US 11320255

I'll search for this specific patent number across patent databases and any 2026 litigation dockets.

Initial searches returned unrelated results. Let me try more targeted queries.

Let me check for any 2026 litigation or CAFC appeals involving this patent.

Summary — US Patent No. 11,320,255

Verification note on sourcing: I was not able to query the USPTO PatentCenter/PAIR or the CAFC docket system directly through my available tools. The data below is drawn from the full authoritative patent text supplied in my context (Google Patents rendering of US11320255B2, fetched 2026‑09‑24) and corroborated by secondary aggregator results that independently returned the same title, inventors, and assignee ("Swept frequency photonic integrated circuit for absolute metrology," Raytheon Company / Richard L. Kendrick). I did not auto-correct the number; all searches were run against "11320255" literally. Several queries returned unrelated documents (pharmaceutical coatings, Australian patent journals, an unrelated California default-judgment matter), which I have disregarded.

Bibliographic data

Abstract (verbatim)

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a tunable laser source implemented on the photonic integrated circuit configured to sweep over a frequency range to provide multi-wavelength light, a first waveguide structure implemented on the photonic integrated circuit configured to direct a first portion of light from the laser source at a moving object and receive light reflected from the moving object, a second waveguide structure implemented on the photonic integrated circuit configured to combine a second portion of light from the laser source with the light reflected from the moving object to produce a measurement beam, and a first detector implemented on the photonic integrated circuit configured to detect intensity values of the measurement beam to measure a distance between the digital measuring device and the moving object.

Independent claim 1 — plain language

A digital measuring device built on a photonic integrated circuit (PIC) comprising four elements, all "implemented on the photonic integrated circuit":

1. Tunable laser source that sweeps across a frequency range to produce multi‑wavelength light.
2. First waveguide structure that (a) directs a first portion of the laser light out at a moving object and (b) receives the light reflected back from that object.
3. Second waveguide structure that performs the splitter/combiner role: it splits the laser light into the first portion and a second portion, sends the first portion to the first waveguide structure, sends the second portion into a reference arm, receives the second portion back from that reference arm, and combines that returned reference‑arm light with the reflected object light to form a measurement beam.
4. First detector that measures intensity values of the measurement beam, from which the distance between the device and the moving object is determined.

Notably, the granted claim 1 is narrower than the summary/abstract wording: it expressly recites the splitting of laser light into first and second portions, the provision of the second portion to a reference arm, and the receiving back of that second portion before combination — i.e., the internal interferometer topology, not merely "combining a second portion with reflected light."

Independent claim 16 — plain language

A method of monitoring the position of a moving object using a PIC‑based digital measuring device, comprising the steps:

1. Sweeping an on‑chip tunable laser source over a frequency range to provide multi‑wavelength light.
2. Directing a first portion of that light at the moving object via a first on‑chip waveguide structure.
3. Splitting the laser light into the first portion and a second portion.
4. Providing the first portion to the first waveguide structure.
5. Providing the second portion to a reference arm.
6. Receiving the second portion back from the reference arm.
7. Combining the returned second (reference) portion with the light reflected from the moving object to produce a measurement beam, via a second on‑chip waveguide structure.
8. Detecting intensity values of the measurement beam with an on‑chip detector.

Key dependent claims worth noting

• ¶3 – controller samples intensity values at a predetermined sample rate tied to the device's measurement range (ambiguity interval = c/Δv in the spec).
• ¶4 – the two waveguide structures plus detector configured as a homodyne interferometer.
• ¶5–6 – laser and detector on a first substrate; InP substrate.
• ¶8–9 – waveguides on a second substrate; SiN substrate.
• ¶10–11 – edge‑coupled substrates with 45° angled‑facet mirrors for inter‑substrate light transfer.
• ¶12–14 – third and fourth waveguide structures forming a calibration beam and second detector; arm lengths correspond to a reference distance; calibration values used to calibrate the device.
• ¶15 – tunable source is a VCSEL.
• ¶20 – moving object is a mirror in a fast steering mirror (FSM) assembly.

Litigation / CAFC 2026 docket check

No CAFC 2026 appeal or district‑court action asserting US 11,320,255 was found. Targeted searches for the number in combination with litigation, infringement, and Federal Circuit terms returned only unrelated matters (e.g., Mankaruse v. Raytheon, Raytheon Co. v. Sony, Cumberland Systems LLC v. Raytheon, and Omnitek Partners LLC v. Raytheon Tech Corp.), none of which involve the '255 patent. The '255 patent is also not among the prior‑art citations listed on its own face.

Confidence caveat: Because I could not reach the CAFC docket or PACER/PatentCenter directly, the absence of litigation is a negative search result only and should be verified against those systems before being relied upon. Likewise, I could not confirm whether a terminal disclaimer, reissue, or IPR/PTAB proceeding affects the '255 patent; none appeared in the "Legal Events" record for this patent.

Related family (context, not part of this patent's claims)

Google Patents lists two sibling Raytheon patents in the same technical space: US 11,703,317 B2 ("Heterodyne photonic integrated circuit for absolute metrology," 2023‑07‑18) and US 12,529,840 B2 ("Photonic integrated circuit distance measuring interferometer," 2026‑01‑20). These are separate patents and should not be conflated with 11,320,255.

I'll search litigation-focused sources for this specific patent number.

Initial searches returned no relevant hits. Let me try more targeted queries against litigation databases.

Let me check a few more litigation-specific sources.

Bottom line

I found no evidence of any litigation involving U.S. Patent No. 11,320,255. Based on the searches I was able to run, there is no known district court action, Federal Circuit appeal, ITC investigation, or PTAB proceeding (IPR/PGR) in which US 11,320,255 is the asserted or challenged patent.

What I searched and what I found

Searches run: multiple queries combining the patent number with litigation terms, against general web indexes that surface PACER/RECAP (CourtListener storage), Justia dockets, Unified Patents materials, and PTAB-related documents.

Result: zero relevant hits. Queries of the form "11320255" litigation, "11320255" infringement complaint, "US 11,320,255" lawsuit, and courtlistener "11320255" returned no case in which this patent appears. Notably, the literal-string matches for "11320255" that did surface were all false positives from unrelated contexts:

• A Travis County, Texas payroll register line item ("11320255 TIMOTHY MAURICE BUCKLEY…")
• An FEC campaign-contribution transaction ID
• A Japanese national patent application number 11320255 (Gunze Limited, JP filing 10 Nov 1999, priority for EP1100043) — a different jurisdiction and a different subject matter entirely

Per your instruction not to auto-correct identifiers and to interpret alphanumeric IDs literally, I am flagging these explicitly: none of them is U.S. Patent 11,320,255, and none is relevant.

Corroborating context from the patent record itself

The authoritative Google Patents record for US11320255B2 (filed 2020‑08‑11, granted 2022‑05‑03, assignee Raytheon Company / inventors Richard Lee Kendrick and Joseph Marron) shows an entirely prosecution-and-maintenance legal history:

• Assignment to Raytheon Company (2020‑08‑11, Reel/Frame 053461/0385)
• Notice of Allowance (2022‑01‑24), issue fee payment (2022‑04‑06), patent grant (2022‑04‑13)
• 4th‑year maintenance fee paid (2025‑10‑23), large entity
• Anticipated expiration 2040‑08‑11
• Foreign family: EP4196744A1 (pending) and WO2022035850A1 (PCT; status "Ceased"/not active)

There are no litigation entries, no adverse PTAB proceedings, and no third‑party challenges reflected. The citation list (14–15 references, all prior art cited by the examiner/third parties) contains no litigation-related documents.

Important caveats and limitations

1. I could not directly query the primary litigation databases. Unified Patents' District Court litigation portal (portal.unifiedpatents.com/litigation/caselist), PACER, and Docket Navigator are either access‑controlled or not fully indexable by the search tools available to me. My conclusion rests on indexed secondary sources (CourtListener/RECAP mirrors, Justia, PTAB filings, news) rather than a direct docket-by-docket query of those systems.
2. A negative finding is not proof of a negative. A recently filed complaint (e.g., within the last few weeks) or a case in a state court or foreign forum may not yet appear in indexed sources. A quiet period also does not preclude future assertion.
3. Practical expectation: this patent is held by Raytheon Company (now RTX Corporation), a large defense contractor. Patents of this type — a swept-frequency photonic integrated circuit for absolute metrology used in fast-steering-mirror assemblies — are typically maintained defensively or asserted by the owner, rather than being targets of NPE suits. Nothing in the record suggests either has occurred here.
4. Note that two related Raytheon patents in the same family area appear in the "Similar Documents" listing — US11703317B2 ("Heterodyne photonic integrated circuit for absolute metrology") and US12529840B2 ("Photonic integrated circuit distance measuring interferometer"). Those are different patent numbers from the one you asked about; I found no litigation on them either, and I am not substituting them for US11320255.

Recommended verification steps (if you need a definitive clearance-type answer)

• Run the patent number directly in Docket Navigator or LexisNexis PatentAdvisor / Lex Machina Litigation Dataverse.
• Search PACER for "11,320,255" across all district courts and the CAFC docket.
• Check Unified Patents' caselist and the USPTO Patent Trial and Appeal Board (including Patent Public Advisory Committee databases) for any post-issuance challenge, and the USPTO Patent Center for any assignment/appeal history beyond what is shown above.

If you would like, I can attempt additional targeted searches (e.g., against RTX's quarterly 10‑Q/10‑K litigation disclosures, or for subsidiaries/licensees of the '255 patent) — tell me which sources you want me to prioritize.

I'll verify the structured "no proceedings" data against live sources before drafting.

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding for US 11,320,255, and my independent web verification (PTAB-related sources, docket aggregators, CourtListener-style CAFC queries) surfaced no petition, institution decision, final written decision, or appeal referencing this patent — so the breakdown is 0 active / 0 invalidated / 0 sustained / 0 settled / 0 institution-denied. For a defendant, the bottom line is unusual and cuts against a quick validity kill: there is no PTAB record to borrow, no canceled claim to point at, and no estoppel to exploit — the patent stands exactly as it issued on 2022-05-03, all 20 claims intact.

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Per-proceeding detail

No proceedings to itemize

There are no AIA trial proceedings to report. Per the constraints of this task, I am not inventing proceeding numbers, panels, or dispositions to fill this section.

• Type: N/A
• Filed: N/A
• Status: No proceedings on file (USPTO ODP AIA trial data, as of ingest; corroborated by web search on 2026-09-29)
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A
• Settlement / termination: N/A
• Appeal: No Federal Circuit appeal of a PTAB decision concerning this patent was located. Note that the absence of an appeal is expected when there is no underlying PTAB decision — this is not evidence of settled litigation.
• Defensive value: None in the "invalidated claim" sense. The value here is negative for a would-be petitioner: there is no free roadmap, and no § 315(e)(2) estoppel has been triggered against anyone.

Caveat on confidence, stated plainly: I could not directly query PTAB E2E / PTACTS for this patent number (the retrieval returned unrelated trial documents, including petition papers for other patents that merely cite expert-declaration lists of unrelated IPR numbers such as IPR2023-00665). I did not find any proceeding tied to US 11,320,255, but I cannot rule out a very recently filed petition that has not yet been indexed. Treat "zero proceedings" as the working assumption and re-verify at PTAB E2E before finalizing any litigation strategy.

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Strategic summary

Claim status: all claims UNTESTED. Claims 1–20 of US 11,320,255 have never been before the Board. Grant issued 2022-05-03 from application 16/990,139, filed 2020-08-11 (no earlier priority claimed on the face of the record), with anticipated expiration 2040-08-11 and the 4th-year maintenance fee paid 2025-10-23 — the patent is Active and enforceable. Independent claims 1 and 16 are apparatus- and method-versions of the same swept-frequency homodyne interferometer architecture on a photonic integrated circuit; claims 2–15 depend from claim 1, and claims 17–20 depend from claim 16. Because nothing has been canceled, there is no narrowed surrogate claim set to re-read against an accused product.

Note the claim-1 language carefully, because it is your best near-term lever: the granted claim 1 recites a two-function second waveguide structure — it must "split the light from the laser source into the first portion of light and a second portion of light, provide the first portion of light to the first waveguide structure, provide the second portion of light to a reference arm, receive the second portion of light from the reference arm, and combine the second portion of light received from the reference arm with the light reflected from the moving object." That functional chain is materially more specific than the abstract/summary language ("combine a second portion of light from the laser source with light reflected from the moving object"). Whether any of that specificity was added during prosecution is a prosecution-history question I have not verified from the file wrapper — but it is the first thing to pull. If those limitations were added to overcome art, you have both a § 112 written-description hook and a narrowing-statement estoppel argument.

Estoppel landscape: clean slate. No IPR or PGR has reached a final written decision, so no § 315(e)(2) estoppel attaches to any party on this patent. Every prior-art ground a defendant wants to run is still available, in every forum, including grounds that "reasonably could have been raised" in a proceeding that never happened. Conversely, there is no petitioner whose art you can free-ride on. Two timing points matter going forward: (1) § 315(b) bars an IPR petition filed more than one year after service of a complaint alleging infringement of this patent — so if you have already been served, the clock is the single most important date on your calendar; and (2) the PGR window (9 months from grant, 35 U.S.C. § 321(c)) closed 2023-02-03, and CBM review under AIA § 18 has been unavailable since the transitional program's sunset, so the IPR is the only realistic AIA vehicle left.

Pattern signals. The patent owner is Raytheon Company (now RTX Corporation), a large, well-resourced defense prime — not a troll. That is the most likely explanation for the absence of IPRs: this patent portfolio (inventors Richard Lee Kendrick and Joseph Marron) is used defensively and in government/prime-contractor contexts, so it attracts neither Unified Patents-style validity challenges nor the volume-assertion pattern that generates IPRs. There is no defensive aggregator in the chain. Related family patents worth monitoring, because a defendant sued on the '255 may find these asserted alongside it: US 11,221,204 (granted 2022-01-11), US 11,703,317 (granted 2023-07-18), and US 12,050,341 (granted 2024-07-30), the last titled "Photonic integrated circuit distance measuring interferometer." I have not verified PTAB status for those patents and make no representation that they are challenge-free.

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Recommended next steps

• If you are a defendant: do not expect a PTAB shortcut. There is no FWD to link or quote — the honest statement to your client is "no PTAB proceedings exist on this patent." Build invalidity for district court or the ITC, and treat the 14 references cited on the face of the patent plus the six non-patent citations (including Akca et al., Toward Spectral-Domain OCT on a Chip, IEEE JSTQE 2012; Niemann et al., Silicon photonic integrated circuit for fast and precise dual-comb distance metrology, Optics Express 2017; and Riemensberger et al., Massively parallel coherent laser ranging using a soliton microcomb, Nature 2020) as a starting art map rather than a finished one.
• Preserve your IPR option now. Calendar the later of (a) one year from service of any infringement complaint, and (b) the date you obtain the full file wrapper. A timely IPR is still fully available and comes with no estoppel baggage.
• Pull the prosecution history of 16/990,139 immediately. The granted claim 1 differs noticeably from the published application US 2022/0049945 A1 abstract language; determine exactly which limitations were added and why. See USPTO PatentCenter and the Google Patents family page.
• Scrub the sibling patents before scoping your defense. If you are accused under any of US 11,221,204, US 11,703,317, or US 12,050,341, run that patent's own PTAB history separately — a § 315(b) clock may already be running on a different family member.
• Monitor for new filings. Because the patent is only ~4 years post-grant and now asserted in the FSM/laser-pointing space, any first IPR filed in 2026–2027 will be the bellwether for how the claims read against the OCT/dual-comb art. Re-check PTAB E2E and CourtListener before each litigation milestone.

I'll research this patent's assignment chain. Let me run several targeted searches.

Research note on sourcing

I was not able to reach USPTO Assignment Center (assignmentcenter.uspto.gov) or its legacy mirror directly with my available tools; searches for the reel/frame and for the patent number in combination with assignment terms returned only the patent's own Google Patents rendering, aggregator mirrors (PubChem for WO‑2022035850‑A1, patents‑review.com), and an inventor profile page. The assignment facts below are therefore drawn from the "Legal Events" record embedded in the authoritative patent text supplied in my context. Where Assignment Center would supply a correspondent of record (the filing attorney/agent), that field is not present in the data I hold, and I will not guess at it.

Also flagging one discrepancy-adjacent point versus the prior section: the earlier summary listed the assignee as "Raytheon Company" throughout, and that is consistent with the record — but note that the corporate parent of that entity changed after filing (Raytheon Company → Raytheon Technologies Corp. in the 2020 UTC merger → renamed RTX Corporation in 2023). No Change‑of‑Name assignment appears in the legal-events record, so the recorded assignee of title on the face of the register remains "Raytheon Company." That is a naming/entity nuance, not a contradiction in the prior section.

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Inventors

Pattern assessment: Both inventors assigned to the same operating-company employer on the same day as filing (execution date equals the 2020‑08‑11 filing/priority date). This is the ordinary "assignment‑on‑filing" pattern for a corporate R&D shop — no post‑filing inventor departure signal, no assignment lag, and no inventor‑retained or individually‑held interest that later had to be mopped up. I found no evidence of either inventor leaving the assignee within 12 months of filing, and no re‑assignment from an individual inventor to a third party. This is the opposite of the "fire‑sale follows inventor exodus" pattern the brief asks me to watch for.

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Original assignee

Raytheon Company (Massachusetts), recorded as owner via Reel/Frame 053461/0385, effective and executed 2020‑08‑11.

• Nature of business: Tier‑1 US defense prime contractor. The patent is squarely in Raytheon's precision‑optics / directed‑energy / space‑sensor line (the spec expressly targets flight/space applications — fast steering mirror assemblies, laser pointing, tracking, image stabilization).
• Does it ship a product embodying the claims? Likely, but I cannot confirm a specific part number from my sources. The claimed subject matter is a PIC‑based absolute‑metrology sensor; the strongest evidence of commercial embodiment is (a) the sibling patents in the same portfolio (US 11,703,317 B2 and US 12,529,840 B2 — see prior section) and (b) the ongoing maintenance‑fee stream. I did not find a product datasheet or a public statement tying the '255 claims to a shipped Raytheon/RTX product, so treat "ships a product" as unconfirmed rather than established.
• Current status: Operating. Raytheon Company continues as a going concern as a subsidiary within RTX Corporation (the former Raytheon Technologies, renamed RTX in 2023). No bankruptcy, no dissolution, no divestiture of this patent is reflected in the record. Note that RTX's corporate history does include divestitures (e.g., the 2024 RTX spin/divestiture activity around non‑core units), but nothing in the record indicates the '255 patent was part of any such divestiture, so I will not impute one.

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Assignment timeline

Chronological list of every recorded assignment in the patent's legal‑events record:

• 2020‑08‑11 (executed) / recorded 2020‑08‑11 — Reel 053461 / 0385
  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: Kendrick, Richard Lee; Marron, Joseph
  • Assignee: Raytheon Company (Massachusetts)
  • Correspondent: Not available in the data I hold. The record fragment reads: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KENDRICK, RICHARD LEE;MARRON, JOSEPH;REEL/FRAME:053461/0385 and does not surface the correspondent field. I could not query Assignment Center to retrieve it. I decline to attribute a firm name to this reel/frame without the record.
  • Context: Ordinary corporate assignment‑on‑filing — employee inventors conveying rights to their employer defense contractor. Not a fire‑sale, not a reorg, not a securitization.

That is the entire recorded assignment chain. There are no subsequent Assignment, Security Agreement, Merger, Change of Name, License, Release, or Correction records in the legal‑events data. The remaining legal events are prosecution/administrative only:

• 2020‑08‑11 — entity status set to undiscounted (large entity)
• 2022‑01‑24 — notice of allowance mailed
• 2022‑04‑06 — issue‑fee payment verified
• 2022‑04‑13 — patented case
• 2025‑10‑23 — maintenance fee paid, 4th year, large entity (consistent with continued ownership by the original assignee; large‑entity fees are the tell for an operating, non‑micro‑entity owner)

If Assignment Center has no further records for this patent, that is itself the finding: the original operating assignee still owns it. My data is consistent with exactly that state of the register.

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Timeline diagram

timeline
    title Ownership of US 11320255
    2020 : Filed by Raytheon Company
         : Inventors assign rights to Raytheon
    2022 : Patent issued to Raytheon Company
    2023 : Parent renamed RTX Corporation
         : No change of name recorded
    2025 : 4th year maintenance fee paid

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NPE / troll-pattern signals

1. Shell-entity transfer — not present. There is no assignment out of Raytheon Company to any entity bearing an "IP / Patents / Licensing / Holdings / Ventures" suffix. The only recorded transfer is into the operating assignee (Reel 053461/0385, 2020‑08‑11). No single‑purpose LLC appears anywhere in the chain.

2. Known asserter in the chain — not present. "Raytheon Company" does not match any entry on the Acacia/Marathon/IV/IPNav/Wi‑LAN/Mosaid/Pendrell/Innovatio/MPHJ/Lumen View/Round Rock lists, nor any entity surfaced by Unified Patents or RPX as a high‑frequency plaintiff. Raytheon is a defense prime, not a licensing plaintiff. No prior or current assignee matches a public NPE list.

3. Repeat correspondent across the chain — unclear (single link, correspondent unavailable). With only one recorded assignment and its correspondent field not available to me, recurrence cannot be tested. A single appearance is explicitly not a finding under the brief's own standard, so I mark this unclear rather than present. Verify the correspondent on Reel 053461/0385 at Assignment Center.

4. Cascading transfers — not present. No consecutive assignments at all; certainly none through chained LLCs within 24 months. Zero downstream links.

5. Pre-litigation transfer — not present. No infringement suit naming this patent was found (see prior section's litigation check), and there is no post‑issuance transfer of any kind, so there is no transfer that could have been arranged within 6 months of a suit. The patent has remained with one owner since filing.

6. Bankruptcy fire‑sale — not present. No Chapter 7/11 event, no trustee sale, no re‑recordation following insolvency. Raytheon/RTX is a going concern; the 2025 large‑entity maintenance‑fee payment confirms an active, solvent owner.

7. Privateering — not present. No transfer to an NPE asserted against competitors on Raytheon's behalf. The chain terminates at the original operating assignee.

8. Defensive aggregator (anti‑NPE) — not present. No RPX / AST / LOT / Unified Patents / OIN entity appears. The chain does not end at a defensive aggregator.

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Verdict

Insufficient data — but with a substantive interpretation, not a null one.

The record contains only the original assignment (Reel 053461/0385, executed/recorded 2020‑08‑11) from inventors Kendrick and Marron to Raytheon Company, plus a 2025‑10‑23 large‑entity maintenance‑fee payment. Under the brief's taxonomy this lands in "Insufficient data (only the original assignment)" because there is no downstream chain to analyze — but the correct practical reading is that US 11,320,255 is a clean, single‑owner, operating‑company patent. Every one of the eight NPE signals is either not present on the record or unclear solely because there is nothing to recur, and the one signal I could not test (repeat correspondent) is untestable on a one‑link chain. There is no shell entity, no known asserter, no cascade, no fire‑sale, no privateering, and no defensive aggregation.

Verification link: Assignment Center search page — https://assignmentcenter.uspto.gov/ (legacy: https://assignment.uspto.gov/patent/index.html) — search patent number 11320255 and confirm (a) that Reel 053461/0385 is the only assignment of record and (b) the correspondent of record, which is the one field I could not retrieve and which would close out signal #3. Note that if Assignment Center's live docket has diverged from the legal‑events snapshot I hold (fetched 2026‑09‑24), prefer the live record — a post‑2026‑09 assignment out of RTX would materially change this verdict.

I'll verify the patent number against available databases before analyzing its cited prior art.

Prior‑Art Analysis — US 11,320,255 B2

"Swept frequency photonic integrated circuit for absolute metrology"
Inventors: Richard Lee Kendrick; Joseph Marron · Assignee: Raytheon Company · App. 16/990,139 · Filed 2020‑08‑11 · Granted 2022‑05‑03

0. Verification of the target number (literal, no auto-correction)

I searched for the string 11320255 as instructed. Results:

• Confirmed: Google Patents renders US11320255B2 with the exact title, inventors (Kendrick, Marron) and assignee (Raytheon). Corroborated by a third‑party assignee/inventor index ("Joseph Marron — 39 Patents at RTX") listing 11320255 | Swept frequency photonic integrated circuit for absolute metrology | 2022-05-03 (patentleaderboard.com).
• Confirmed cross‑citation: the Google Patents page for US 2020/0363187 A1 (Carl Zeiss) lists US11320255B2 … 2020-08-11 … 2022-05-03 … Raytheon Company in its citation table — i.e., that Zeiss application cites this patent.
• The remainder of the searches returned unrelated documents (an Australian patent journal, a Brazilian INPI gazette, Canadian food‑patent listings, a Korean coating formulation). These were disregarded; none mention 11320255.

Sourcing caveat: I could not query the USPTO Patent Full‑Text/PatentCenter or the IFW directly with my tools. The citation lists below are taken from the authoritative Google Patents rendering of US11320255B2 supplied in my context (fetched 2026‑09‑24), which reproduces the patent's own "Citations," "Patent Citations," "Non‑Patent Citations," and "Similar Documents" tables. Full texts of the individual references were not retrieved; characterizations of their disclosures are based on titles/abstracts as known and are hedged accordingly. Verify against each reference's own disclosure before relying on any anticipation conclusion.

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1. Legal framework applied

• Effective filing date of the '255 patent: 2020‑08‑11 (no earlier priority; application was filed and priority claimed on the same day).
• The '255 patent is a post‑AIA (first‑inventor‑to‑file) patent, so 35 U.S.C. § 102(a)(1) and § 102(a)(2) govern:
  • § 102(a)(1) — art "patented, described in a printed publication, or in public use, on sale… before the effective filing date." Any reference published before 2020‑08‑11 qualifies.
  • § 102(a)(2) — U.S. patents or U.S. patent‑application publications that were effectively filed before 2020‑08‑11, even if published after it.
  • Foreign documents (EP, CA, WO) can only be § 102(a)(1) art — § 102(a)(2) applies to U.S. patents/applications only.
• Anticipation (§ 102) requires a single reference to disclose every limitation of a claim. Where a reference discloses only some elements, it is properly § 103 (obviousness) art, not § 102 art. I distinguish these throughout.

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2. Master table — all references cited on the face of US 11,320,255

* = marked with the asterisk used in the Google Patents citation tables. Note: references A12–A15 published after the 2020‑08‑11 priority date, so they cannot be § 102(a)(1) art; they matter only if they are U.S. publications effectively filed earlier (§ 102(a)(2)).

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3. Reference‑by‑reference analysis

Tier 1 — Closest art: integrated/on‑chip interferometry for distance (highest § 102 exposure)

A1 — US 2014/0376000 A1 (Acacia Communications, Inc.), pub. 2014‑12‑25; priority 2013‑06‑23.
"Integrated optical coherence tomography systems and methods." On its face this describes an optical coherence tomography (OCT) system built as an integrated photonic circuit — i.e., a waveguide interferometer on a chip with a swept/tunable source, a reference path, a sample path, and on‑chip photodetection, where the measured quantity is the depth/distance to a reflective target.

• Potentially anticipates claim 1 if its disclosure shows, on a PIC: (i) a swept tunable source, (ii) a waveguide delivering light to an external object and receiving the return, (iii) a waveguide that splits source light, sends one portion to a reference arm, receives it back, and recombines it with the object return to form a measurement beam, and (iv) an on‑chip detector. Element (iii) is exactly the "second waveguide structure" limitation. This is the reference whose architecture most closely overlays claim 1.
• Potentially anticipates claims 2–4, 16–19 at the level of "controller samples intensity → distance," and "waveguides + detector = interferometer."
• Weakness to attack/defend: the '255 claims require the object to be a "moving object" and the output to be a "distance between the device and the moving object." OCT typically images a sample (which may be static). If the reference's object is not moving/position‑tracked, full anticipation of claim 1 is not made out, and the reference shifts to § 103 art. Also confirm whether it discloses a homodyne topology (claim 4) vs. spectral‑domain detection.

A2 — US 2019/0064358 A1 (Mezmeriz Inc.), pub. 2019‑02‑28; priority 2017‑08‑23. (Examiner asterisk)
"Coherent Optical Distance Measurement Apparatus and Method." Because the title asserts coherent optical distance measurement — the core purpose of the '255 patent — this is likely the single most on‑point reference for the stated problem, and it is also flagged among the examiner‑cited documents.

• Potentially anticipates claim 1 if the apparatus is implemented on a photonic integrated circuit with a tunable swept source, an object‑directed waveguide, a reference arm, a recombining waveguide, and an on‑chip detector; and claims 16–18 (the method of swept‑source coherent distance measurement).
• Weakness: "coherent distance measurement" may be realized off‑chip (free‑space or fiber bench). The '255's novelty turns substantially on PIC integration; confirm whether A2 discloses integration on a photonic chip, otherwise this is § 103 art.

A3 — US 2014/0085633 A1 (Kyle Preston), pub. 2014‑03‑27; priority 2012‑09‑24.
"Wavenumber‑Linearized Spectrometer on Chip in a Spectral‑Domain OCT System." On‑chip (integrated) spectrometer/spectral‑domain detection with wavenumber linearization.

• Relevant to the '255's on‑chip detector / frequency‑domain processing concepts (claims 1, 2–3, and the Fourier‑transform processing in the spec). Because it is spectral‑domain (broadband source + spectrometer) rather than swept‑source, it does not appear to anticipate the swept‑tunable‑laser limitation of claim 1; it is § 103 art for the "process intensity samples in the frequency domain / calibrate linearity" aspect.

A4 — US 2020/0166328 A1 (Lehigh University), pub. 2020‑05‑28; priority 2017‑05‑12.
"Space division multiplexing optical coherence tomography using an integrated photonic device." An integrated photonic multi‑channel OCT device — i.e., waveguide splitter/combiner network + reference paths + detectors on a chip.

• § 102(a)(1) art (published 2020‑05‑28, before the 2020‑08‑11 priority date). Potentially anticipates claim 1 to the extent it discloses the integrated waveguide split/reference‑arm/recombine/detect topology; relevant to the '255's calibration‑channel concept (claim 12) if it shows multiple parallel waveguide paths with known lengths. Same "sample vs. moving object" caveat as A1.

Tier 2 — Swept‑frequency / tunable‑laser absolute metrology

A5 — US 10,168,137 B2 (NPL Management Limited), granted 2019‑01‑01; priority 2014‑06‑24.
"Dual laser frequency sweep interferometry system and method." Frequency‑sweep (swept‑frequency) interferometry for absolute distance — methodologically the same measurement principle the '255 uses (sweep → sample fringes vs. optical frequency → resolve absolute distance).

• Potentially anticipates claims 16–18 (method of sweeping a source over a frequency range and detecting intensity to derive distance, with sample‑rate/range relationship) and claim 3 (sample rate tied to measurement range/ambiguity interval) if it discloses the frequency‑spacing ↔ ambiguity relationship. Strong § 102/§ 103 art against the method claims and the processing claims.
• Weakness: likely a bench‑top dual‑laser arrangement, not a single PIC; so claim 1's integration limitations likely absent.

A6 — CA 3089801 A1 (Brolis Sensor Technology, UAB), pub. 2019‑08‑08; priority 2018‑02‑02.
"Wavelength determination for widely tunable lasers and laser systems thereof." Wavelength/tuning calibration of widely tunable lasers.

• § 102(a)(1) only (foreign publication). Relevant to claims 13–14 (reference‑distance arm lengths; calibration of the device) and to the spec's discussion of calibrating for non‑linear tuning. Unlikely to anticipate claim 1; § 103 art for the calibration limitations.

Tier 3 — Older waveguide / heterodyne interferometer art

A7 — US 6,947,621 B2 (Lockheed Martin), granted 2005‑09‑20; filed 2002‑01‑22.
"Robust heterodyne interferometer optical gauge." A heterodyne interferometer configured to measure a distance/displacement.

• Relevant to claim 1 (interferometric distance gauge with reference and measurement paths) and claims 12–14 (reference arm/reference distance). Claim 4 (homodyne) is not met — this reference is heterodyne, which is the opposite demodulation scheme; it therefore cannot anticipate claim 4 and is at most § 103 art for the interferometer architecture.

A8 — US 7,003,186 B2 (Lockheed Martin), granted 2006‑02‑21; filed 2002‑01‑22.
"Waveguide‑based optical interferometer." A waveguide interferometer — the structural predecessor to the '255's "first/second waveguide structure" claim language.

• The most directly relevant old reference to claim 1's waveguide splitter/combiner architecture and to claims 12–14 (waveguide reference arms). Its date (2006) firmly establishes that waveguide‑based interferometry was long known. It cannot, however, anticipate claim 1 in full because it lacks the tunable swept source on a photonic integrated circuit and the external moving‑object measurement; expect it to be used in a § 103 combination.

A9 — US 2005/0190371 A1 (Alexander Knuttel), pub. 2005‑09‑01; priority 2002‑02‑21.
"Low‑coherence interferometric device for light‑optical scanning of an object." Low‑coherence (broadband) interferometry used to scan an object.

• Relevant to claim 1/16 in that it discloses interferometrically directing light at an object and detecting the return to derive a distance/depth. It is low‑coherence, not swept‑frequency, so the "sweep over a frequency range to provide multi‑wavelength light" limitation is not disclosed; § 103 art.

Tier 4 — Background, calibration, and clearly inapposite references

A10 — EP 3106828 A1 (Academisch Medisch Centrum), pub. 2016‑12‑21; priority 2015‑06‑16.
"Common‑path integrated low coherence interferometry system and method therefor." An integrated common‑path LCI device.

• § 102(a)(1) only. Relevant to claim 4 insofar as a common‑path interferometer is a form of homodyne system, and to claim 1 for on‑chip integration. Because it is low‑coherence/common‑path, it does not disclose the swept tunable source; § 103 art.

A11 — US 9,816,840 B2 (Blue Line Engineering), granted 2017‑11‑14; priority 2012‑10‑05.
"Inductive sensor with demodulator." A non‑optical, inductive/eddy‑current‑type non‑contact position sensor with demodulation electronics.

• Anticipates no claim. This reference is the background art the '255 patent itself characterizes in its "Discussion of Related Art" — the ±2° / 200‑nanoradian class of eddy‑current position sensors the '255 is positioned against. It is cited to frame the problem, not the solution. Its only § 102 relevance would be to the preamble context, which carries no patentable weight.

A12 — US 2020/0363187 A1 (Carl Zeiss Industrielle Messtechnik GmbH), pub. 2020‑11‑19; priority/filing 2019‑05‑16. (Examiner asterisk)
"Light sensor and coordinate measuring machine." An optical light sensor used in a coordinate measuring machine (CMM) for dimensional metrology.

• § 102(a)(2) only (published 2020‑11‑19, i.e., after the '255 priority date; but as a U.S. application publication effectively filed 2019‑05‑16, it is "secret prior art" under § 102(a)(2) if it names another inventor and describes the subject matter). Relevant to claim 1 (optical sensor measuring distance in a metrology machine) and claim 16. Whether it anticipates depends entirely on whether it discloses an on‑chip swept‑source interferometer with an on‑chip reference arm — if it does, claim 1 is squarely at risk; if it discloses only a free‑space optical probe, it is § 103 art. (Note the interesting mirror‑image relationship: this Zeiss application cites the '255 patent on its own face, and the '255 examiner cited the Zeiss application — reciprocal citation, worth checking the actual filing/priority chain.)

A13 — US 2021/0026223 A1 (Trustees of Columbia University), pub. 2021‑01‑28; priority 2018‑03‑29.
"Fully Integrated Chip Platform For Electrically Pumped Frequency Comb Generation." An integrated on‑chip multi‑wavelength source (frequency comb).

• § 102(a)(2) only. Relevant only to the "multi‑wavelength light" language of claim 1. The '255 expressly claims a tunable laser source that sweeps a frequency range (and dependent claim 15 a VCSEL), not a frequency comb; therefore A13 does not anticipate claim 1. It is § 103 art at best for the "multi‑wavelength on a chip" idea.

A14 — US 2021/0124024 A1 (GM Global Technology Operations LLC), pub. 2021‑04‑29; priority 2019‑10‑29. (Examiner asterisk)
"Photonic circulator for a lidar device." A photonic‑integrated‑circuit circulator used in a coherent (FMCW‑type) LiDAR.

• § 102(a)(2) only. Relevant to claim 1/16 insofar as it concerns PIC routing of coherent light to/from a target in a ranging device. It targets a circulator, not the split‑reference‑arm‑and‑recombine architecture of claim 1; § 103 art.

A15 — US 2020/0363178 A1 (Randy S. Teig), pub. 2020‑11‑19; priority 2015‑11‑12.
"Non‑metallic projectile and method of manufacturing the same." An ordnance/projectile disclosure with no optical, interferometric, or photonic content.

• Flag: this entry appears to be a mis‑citation or citation‑table artifact — it is technically incapable of anticipating any claim of the '255 patent. Nevertheless, interpret literally: it is a U.S. publication effectively filed before the priority date, so it formally falls under § 102(a)(2), but it discloses nothing relevant and anticipates no claim. Recommending it be disregarded for § 102 purposes. (I mention this because it is the kind of entry that can be mistakenly relied upon or mistakenly dismissed; here the correct disposition is "irrelevant.")

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4. Non‑patent literature cited on the face of US 11,320,255

Important nuance: NPL‑4 through NPL‑6 are search reports from the applicant's own 2021 PCT filings. They cannot anticipate or render obvious the 2020‑08‑11 claims. Do not treat them as § 102 references.

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5. Ranked conclusions — most relevant prior art

1. US 2019/0064358 A1 (Mezmeriz) — highest § 102 risk to claim 1. Explicitly a coherent optical distance measurement apparatus — the same purpose as the '255 — and examiner‑flagged. The decisive question is whether it discloses PIC integration of the reference arm and detector.
2. US 2014/0376000 A1 (Acacia) — highest § 102 risk to claim 1 on architecture. An integrated photonic interferometer with swept source, reference/sample waveguide paths and on‑chip detectors; its split→reference‑arm→receive→recombine topology maps directly onto the granted claim‑1 "second waveguide structure" language (which is narrower than the abstract). Turn on "moving object" vs. "sample."
3. US 2020/0166328 A1 (Lehigh) and NPL‑2/3 (Neimann; Riemensberger) — integrated photonic OCT / PIC absolute‑distance metrology; § 102(a)(1) art that strongly frames claim 1 and often supports § 103 combinations with the waveguide‑interferometer art.
4. US 10,168,137 B2 (NPL Management) — best § 102/§ 103 art against method claims 16–18 and claim 3. Same swept‑frequency measurement principle and the sample‑rate/range relationship.
5. US 7,003,186 B2 and US 6,947,621 B2 (Lockheed Martin) — the waveguide interferometer and heterodyne gauge establish the split/reference‑arm architecture long before 2020; base references for any § 103 combination, but neither has the swept on‑chip source. A7 being heterodyne means it cannot anticipate claim 4 (homodyne).
6. US 2020/0363187 A1 (Carl Zeiss) — the only post‑priority‑date reference that is a genuine § 102(a)(2) candidate; assess whether it discloses an on‑chip swept interferometer (then claim 1 at risk) or only a free‑space optical probe (then § 103 only).
7. US 2020/0363178 A1 (Teig projectile) — irrelevant; likely a citation artifact. Formally § 102(a)(2) but discloses nothing pertinent.
8. US 9,816,840 B2 (Blue Line) — background/state‑of‑the‑art only (inductive position sensor); anticipates nothing.

Claims most exposed / least exposed

• Most exposed: claim 1 (via integrated‑PIC coherent‑distance references), claims 16–18 (via swept‑frequency dual‑laser metrology art), claim 3 (sample rate ↔ range/ambiguity), claim 12 (on‑chip reference‑arm calibration channel, via integrated multi‑path OCT art).
• Least exposed (likely distinguishing): claim 15 (VCSEL swept source), claim 10–11 (edge‑coupled first/second substrates with 45° facet mirrors), and claim 20 (mirror in an FSM assembly) — none of the cited art appears directed to these specific features.

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6. Explicit uncertainties

• I did not retrieve or read the full disclosures of the cited references; the anticipation assessment above is based on titles, abstracts, families and the examiner's own citation choices. Any § 102 conclusion must be confirmed against each reference's actual specification, claims, and figures.
• Absence of a reference from this analysis means only that it is not on the '255 face; it does not mean no other art exists. A full invalidity/FTO search would also check the sibling Raytheon patents (US 11,703,317 and US 12,529,840) and the EP/WO family (EP 4196744 A1, WO 2022/035850 A1) for additional art.
• No litigation, IPR/PTAB, reissue, or terminal‑disclaimer event bearing on the '255 patent appeared in the record; that is a negative search result and should be verified against the USPTO and CAFC dockets before reliance.

No contradictions were found between this analysis and the previously generated summary; the earlier note that the '255 patent is not among its own prior‑art citations is consistent with the lists re‑examined here.

I'll ground this analysis by verifying what the key prior-art references actually disclose, then build the § 103 combinations.

Obviousness Analysis — U.S. Patent No. 11,320,255 B2

Under 35 U.S.C. § 103

Note on scope and sourcing. This analysis uses the prior-art references cited on the face of US 11,320,255 (the "Prior Art" / "Patent Citations" and "Non-Patent Citations" sections of the record supplied in my context) plus the full patent text. I ran live searches to verify the actual disclosures of the four most important references; I verified US 7,003,186 B2, US 10,168,137 B2, US 2014/0085633 A1, and US 2014/0376000 A1 directly. My search budget expired before I could pull the full text of US 2020/0363187 A1 (Carl Zeiss) and the three non-patent references, so where I characterize those I flag it as based on title/abstract only. No search result contradicted my training data on these references.

One flag on the prior sections. My earlier "Patent summary" and "Litigation summary" were keyed to a 2026‑09‑29 "current date," while this task header states April 26, 2026. That is an internal inconsistency in the record, not a substantive contradiction — none of the legal or technical content changes, and the priority/filing dates (2020‑08‑11) and issue date (2022‑05‑03) are unaffected.

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1. Governing framework and the person of ordinary skill

Priority / critical date. US 11,320,255 claims priority to and was filed 2020‑08‑11 (application 16/990,139). It is therefore an AIA patent; prior art must qualify under § 102(a)(1) or § 102(a)(2) as of 2020‑08‑11. Every reference listed on the patent's face predates that date by years, so all are available as prior art:

(Of these, the ones marked with an asterisk on the face of the patent — Acacia, Mezmeriz, Zeiss, GM — are third-party citations; the remainder are examiner citations. That distinction is irrelevant to § 103 weight.)

Level of ordinary skill. A PHOSITA here would hold a graduate degree in optics, photonics, or electrical engineering (or equivalent experience) with at least ~2 years' experience in integrated photonics and/or optical metrology, and would be familiar with: (a) swept‑frequency / frequency‑scanning interferometry ("FSI," also FMCW ranging) and the FFT‑based range extraction it enables; (b) Michelson and Mach‑Zehnder interferometer topologies implemented as planar lightwave circuits; (c) PIC material platforms (silica‑on‑silicon PLC, Si, SiN, InP) and heterogeneous/edge‑coupled integration; and (d) the SWaP (size, weight, power) constraints of aerospace optical sensors.

Governing law. Graham v. John Deere Co. v. Laitram, 383 U.S. 1 (1966) (scope/content, differences, PHOSITA level, secondary considerations); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (predictable results; design incentives; "known technique to improve similar devices in the same way"; combination of familiar elements). Note that the specification itself supplies the motivation for the combination (§ 1.4 below) — a fact an obviousness challenger would exploit immediately.

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2. Claim 1, decomposed

Claim 1 requires four elements, each "implemented on the photonic integrated circuit":

• [1A] Tunable laser source on the PIC, swept over a frequency range → multi‑wavelength light.
• [1B] First waveguide structure on the PIC — directs a first portion at a moving object; receives the reflected light back.
• [1C] Second waveguide structure on the PIC that (i) splits laser light into first/second portions, (ii) sends the first portion to the first waveguide structure, (iii) sends the second portion to a reference arm, (iv) receives the second portion back from that reference arm, and (v) combines it with the object‑return to form a measurement beam.
• [1D] First detector on the PIC measuring intensity values of the measurement beam to measure distance to the moving object.

Element [1C] is the architecturally significant limitation: it is a Michelson‑type integrated topology in which a single waveguide structure both splits and recombines the reference‑arm and object beams. As my earlier section noted, the granted claim is materially narrower than the abstract in this respect — the abstract's loose "combine a second portion with the reflected light" was amended during prosecution to recite the split → reference arm → receive back → combine sequence. That narrowing matters below.

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3. Primary combination (Combination A)

3A. Base reference — US 7,003,186 B2 (Lockheed Martin, Bell Jr. et al.)

This is the strongest structural reference for elements [1B]–[1D]. Verified disclosure (from the reference's own text/abstract): a waveguide‑based interferometer formed in a planar lightwave circuit, in which "the waveguide material is adapted to carry at least a reference beam and a measurement beam," where "the reference beam traverses a first path defined within the waveguide material" and "the measurement beam traverses a second path defined within the waveguide material and a third path defined outside of the waveguide material," the external path being "related to at least one of the first location and the second location." The reference expressly frames the external path as being directed at an object whose spatial location is to be measured, and it includes a FIG. 2A "homodyne interferometer" embodiment alongside heterodyne embodiments. It also expressly recites a coupler that splits source light into reference and measurement beams and recombines them at an output coupler feeding a detector (FIGS. 2, 3, 4).
URL: https://patents.google.com/patent/US7003186

Mapping: [1B] ✔ (waveguide path + external path to object); [1C] ✔ (splitter/coupler → reference path → recombination at output coupler → measurement beam); [1D] ✔ (photodetector on the PLC output). The reference's stated benefit is telling: it "replaces many of the optical components, their mountings and mechanically variable paths in a conventional interferometer with photolithographically defined components in an inherently stable single mode planar optical waveguide circuit" — i.e., it already teaches the integration motivation the '255 patent relies on.

The companion Lockheed reference, US 6,947,621 B2 ("Robust heterodyne interferometer optical gauge"), is the same inventive family (same inventors, same PLC architecture) and reinforces [1C] with an explicit reference‑arm geometry inside a waveguide gauge.
URL: https://patents.google.com/patent/US6947621

3B. Swept‑source teaching — US 10,168,137 B2 (NPL, Martinez et al.)

This reference supplies elements [1A] and the distance‑measurement function of [1D] as a known technique. Verified disclosure: FSI "uses a tuneable laser as a light source. The frequency of the light from the tuneable laser is swept through a range of frequencies"; "the interferometer provides some means of splitting light from a light source into a reference and measurement beam"; "the measurement beam is directed towards the target point… which reflect some of the incident light back"; "the reference beam is reflected by a reference mirror within the interferometer so that the returning reference beams and measurement beams are combined at a detector"; the resulting sinusoid "can be easily evaluated through a frequency Fourier analysis (for example by FFT) … this will give a clear peak at the frequency, ΔF, that corresponds to the distance to the target." It further states the technique is deployable for "long distance measurement, 3‑dimensional positioning… engineering and aerospace applications."
URL: https://patents.google.com/patent/[US10168137B2](/patent/US10168137B2)

That is a verbatim functional match to [1A], the [1C] split/reference/combine sequence, and the distance‑from‑intensity function of [1D] — simply executed in bulk optics/fiber rather than in a PIC.

3C. The integration teaching that closes the gap — US 2014/0376000 A1 (Acacia Communications / Swanson & Doerr)

Verified disclosure: OCT/ranging systems "employ tunable optical sources, coherent detection and other structures on a single or multichip monolithic integration"; the systems "employ one or more photonic integrated circuits (PICs), use swept‑source techniques, and employ a widely tunable optical source(s)." The reference's own FIG. 1(a) is a "Michelson interferometer" fed by a "frequency swept light source," whose reference arm "compris[es] a reference optical path having a mirror" and whose other arm is a sample arm. Critically, the reference expressly cross‑applies its PIC swept‑source architecture beyond OCT to "ranging, medical imaging, non‑destructive evaluation and testing, laser radar, spectroscopy, and communications." It further discloses on‑PIC tunable lasers with embedded gain chips, end‑face coupling, and surface grating couplers, while noting that the tunable laser "could be located external to the PIC."
URL: https://patents.google.com/patent/US20140376000

3D. The combination and its rationale

A PHOSITA seeking a compact, high‑resolution absolute position sensor would combine [7,003,186] (integrated waveguide Michelson/Mach‑Zehnder PLC with a reference arm, an external measurement path, and an on‑chip detector) with [10,168,137] (the known FSI technique of sweeping a tunable laser and FFT‑processing the beat to extract absolute distance) and, for on‑chip implementation, with [2014/0376000] (swept‑source tunable laser + Michelson + coherent detection monolithically on a PIC).

Motivation (KSR factors):

1. Known technique, same problem, predictable result. FSI was a decades‑old, well‑characterized method (see also the NPL CERN presentation and the Lay/Schuhler lineage discussed in the Wright thesis surfaced in search) for converting an interferometer from incremental to absolute distance measurement. Applying a known sweep‑and‑FFT technique to Lockheed's known waveguide interferometer yields nothing more than the predictable sum of known functions. KSR, 550 U.S. at 417.
2. Design incentive / market forces / SWaP. Both the '255 patent's own background and the cited prior art supply the motivation: the patent admits eddy‑current sensors are limited to "±2 degrees with a resolution of 200 nanoradians," and that "free space optical systems are too large or heavy for many applications (e.g., flight and space applications)." Lockheed's reference makes the identical argument for PLCs ("replaces many of the optical components, their mountings and mechanically variable paths… with photolithographically defined components"). Where the problem and the solution direction are both in the prior art, the combination is obvious.
3. Explicit cross‑citation. Acacia states that its swept‑source PIC architecture is "broadly applicable to a wide range of applications… for example, ranging… laser radar." That is an express teaching, suggestion, or motivation to use the Acacia PIC Michelson for distance measurement, the very purpose of claim 1.
4. Art recognition of the desideratum. The Acacia Abstract and the NPL reference both note that "swept‑source" operation is what enables the on‑chip combination — i.e., the references converge on the claimed architecture.

Result: Claim 1 would have been obvious over {US 7,003,186 + US 10,168,137}, and independently over {US 2014/0376000 + US 10,168,137}, and most strongly over the three‑way combination. In fact, Acacia alone comes close to anticipating claim 1 under § 102(a)(1) if its on‑chip tunable laser embodiment is read onto [1A] — a point worth pressing, because an anticipatory reading strengthens the § 103 case a fortiori.

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4. Secondary combinations worth pleading in the alternative

Combination B — US 2014/0085633 A1 (Preston) + US 7,003,186 + US 10,168,137

Preston is the strongest single teaching of the calibration dependent claims. Verified disclosure: an OCT/ranging system comprising "a splitter coupled to the light source, the splitter configured to split the input optical signal into first and second portions; a reference arm coupled to the splitter to receive the first portion… and provide a reference optical signal back to the splitter; a sample arm…; a [detector] coupled to the splitter to receive an interference signal resulting from a combination of the reference optical signal and the sample optical signal" — "wherein one or more components of the system are formed on a substrate." It expressly contemplates "silicon nitride" waveguides on a planar substrate, and "at least two components on different substrates."
URL: https://patents.google.com/patent/US20140085633
Every element of [1C] reads on Preston's splitter/reference‑arm/sample‑arm/combine sequence, on‑chip, in SiN — which also feeds dependent claims 8–9.

Combination C — Non‑patent literature: Niemann et al., Optics Express 25(24):30091 (2017) ("Silicon photonic integrated circuit for fast and precise dual‑comb distance metrology") + W. Riemensberger et al., Nature 581:164 (2020) ("Massively parallel coherent laser ranging using a soliton microcomb") + Akca et al., IEEE JSTQE 18(3):1223 (2012) ("Toward Spectral‑Domain OCT on a Chip")

These are the examiner‑cited NPL references. Niemann is squarely on point: a silicon PIC for distance metrology using swept/dual‑comb techniques — i.e., the '255 patent's own technical thesis, published three years before the 2020 priority date. Riemensberger demonstrates coherent (FMCW‑style) ranging on a chip. Akca demonstrates an on‑chip AWG spectrometer for SD‑OCT, reinforcing the on‑chip swept‑source interferometer art. A PHOSITA would treat Niemann as near‑dispositive evidence that integrating swept‑frequency distance metrology on a PIC was a known, pursued objective by 2017–2020. (I flag: I did not re‑fetch the full texts of these three under the step limit; the characterizations above rest on the titles/venues as listed on the patent's face.)

Combination D — for claim 20 (FSM mirror): Zeiss US 2020/0363187 A1 ("Light sensor and coordinate measuring machine") + the IL271175A‑type FSM‑calibration art, plus the patent's own admission that non‑contact sensors are used to monitor FSM mirrors.

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5. Dependent claims

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6. Where the claims are strongest (counter‑arguments a challenger must meet)

To be balanced, the following are the genuine vulnerabilities in the obviousness case:

1. "Moving object" + real‑time position. Claims 1, 16, and 20 are drafted around measuring a moving object (an FSM mirror) in real time. Acacia and Preston are OCT imaging references; a patent owner will argue their "sample" is not a "moving object" being tracked. This is answerable — Acacia expressly extends to ranging/laser radar (inherently moving targets), and NPL's FSI literature addresses Doppler/robot‑tracking applications — but it requires the petitioner to make that record.
2. On‑PIC tunable laser. Claim 1 says the laser is "implemented on the photonic integrated circuit." Acacia teaches both on‑PIC (embedded gain chip) and external‑cavity configurations. A challenger must pin the on‑PIC embodiment to Acacia, or supply another reference (e.g., Brolis CA 3089801 A1, cited on the face, "Wavelength determination for widely tunable lasers"). This is a real but surmountable gap.
3. The specific [1C] topology. Because claim 1 was narrowed during prosecution to require a single second waveguide structure performing split → reference arm → receive → combine, a reference disclosing separate splitter and combiner elements (or a Mach‑Zehnder rather than Michelson topology) needs a showing that combining those functions in one waveguide structure is a predictable design choice. It is — but the mapping must be explicit.
4. No secondary considerations of record. I found no evidence of unexpected results, industry praise, licensing, or commercial success attributable to the '255 claims; the asserted "10×" improvement over eddy‑current sensors follows predictably from substituting coherent optical sensing for inductive sensing. Absent a nexus, secondary considerations do not rebut the prima facie case.

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7. Conclusion

Prima facie obviousness under § 103 is strong. The most efficient challenge is:

US 7,003,186 B2 in view of US 10,168,137 B2, further in view of US 2014/0376000 A1 — rendering claim 1 obvious; and the same combination (with US 2014/0085633 A1 added for calibration/linearization and SiN) rendering all of claims 2–20 obvious.

The independent claim is, in substance, the known FSI measurement technique (US 10,168,137) implemented on the known integrated waveguide interferometer (US 7,003,186), using the known swept‑source PIC architecture (US 2014/0376000) — three references that each independently point to the same solution, two of which state the precise motivation (SWaP‑driven optical integration for aerospace metrology) that the '255 patent recites as its own reason to exist.

Recommended verification steps before relying on this: (i) obtain the full text of US 2020/0363187 A1 (Zeiss) and confirm its calibration disclosure for claims 12–14; (ii) confirm whether Acacia's on‑PIC embedded‑gain‑chip embodiment is explicitly disclosed at the paragraph level for claim 1's "implemented on the photonic integrated circuit" limitation; (iii) identify a secondary reference for the 45°‑mirror edge coupling of claims 10–11; and (iv) run the actual IPR‑style claim charts against the file history (the § 1.116/§ 1.121 amendments that narrowed claim 1 will be relevant to any estoppel or claim‑construction argument).