US 11320256

I'll search for authoritative records on this patent, including any 2026 CAFC activity.

The first searches returned unrelated documents. Let me query more specifically.

Good progress. Let me check for the actual claim text and any litigation/docket records.

US 11,320,256 B2 — Summary

Important caveat up front: the authoritative full text you supplied includes the front matter, classification, and the full descriptive/summary disclosure, but it does not reproduce the granted claim set verbatim. My claim overview below is derived from the "summary of exemplary embodiments" passages of that text and should be treated as a characterization, not a literal quotation of the issued claims. Two of my searches timed out or returned generic/irrelevant hits, so I could not independently pull the USPTO claims pane or a CAFC docket sheet.

Bibliographic data (grounded in the supplied Google Patents full text; cross-checked against PubChem US-11320256-B2)

Abstract (as given in the supplied record)

"Exemplary apparatus can be provided which can include a laser arrangement that is configured to provide a laser radiation, and including an optical cavity. The optical cavity can include a dispersive optical waveguide first arrangement having first and second sides, and which is configured to (i) receive at least one first electro-magnetic radiation at the first side so as to provide at least one second electro-magnetic radiation, and (ii) to receive at least one third electro-magnetic radiation at the second side so as to provide at least one fourth electro-magnetic radiation. The first and second sides are different from one another, and the second and third radiations are related to one another. The optical cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the fourth radiation so as to provide the first electro-magnetic radiation to the first arrangement. The laser radiation can be associated with at least one of the first, second, third or fourth radiations."

Plain-language overview of the independent claims

Based on the summary-of-embodiments section, the independent claims appear to fall into two families — laser/source claims and imaging/method claims:

1. Laser-source apparatus (ring cavity with a two-sided dispersive waveguide). A laser whose cavity contains (a) a dispersive optical waveguide element — e.g., a fiber Bragg grating, chirped FBG, or FBG array — that is addressed from both ends (radiation in one side → radiation out the other, and vice versa, with the second and third radiations related to each other), and (b) an active optical modulator that modulates the returning radiation to re-inject it into the dispersive element. The laser output is one of these circulating radiations. In plain terms: a wavelength-stepped laser that uses a single dispersive element bidirectionally to produce a rapid, stepped-wavelength output.

2. Laser + interferometer + scanner apparatus (imaging system). The same laser arrangement, plus an interferometer that forms a sample-arm beam and a reference-arm beam and generates an interference signal, plus a beam-scanning arrangement that scans the sample beam over the sample. The combination of laser, interferometer, and scanner yields a three-dimensional measurement of an optical property of the sample. Variants add an analog-to-digital acquisition unit clocked by a clock phase-locked to the signal generator driving the modulator, and may use two dispersive elements (which may be FBGs or parts of one FBG) that are reflections off either side.

3. Discrete-frequency ("comb") source apparatus. A laser arrangement producing radiation at N discrete optical frequencies, with each line width < 10 GHz and inter-line spacing > 20 GHz, stepping between frequencies at > 20 million steps/second; the source may use a continuous FBG or FBG array longer than 2 meters. Combined with an interferometer and a beam scanner. In plain terms: a very fast, widely-spaced wavelength-stepping comb source for data-efficient depth ranging.

4. Method / computer-accessible medium — real-time video display. A computer-readable medium causing a computer to display a video stream of a structure from OCT measurements, where the latency between measurement and display is less than 1 second, and where the process is used to interactively guide a medical procedure using that video stream (measurement performed with a frequency-comb source or the laser described above).

5. Method / computer-accessible medium — medical procedure guidance. A parallel claim set directed to performing a measurement in the context of a medical procedure on an anatomical structure (again with the comb source or the described laser).

6. Method / computer-accessible medium — 4D-to-2D compression. Software that transforms four-dimensional interferometric data into two-dimensional video data by compressing one spatial dimension, where the compression includes (i) locating the position of the surface of the structure within the 4D data and (ii) controlling the compression using that surface position; the resulting 2D video stream is displayed. In plain terms: surface-tracking-based flattening of volumetric OCT data into a live 2D display.

The core technical concept across these claims is "optical-domain subsampling" (OS-OCT): a wavelength-stepped (not swept) source with widely spaced discrete wavenumbers causes depth signals to alias into a narrow baseband window, so a large physical depth range (the disclosure cites >3 cm depth of field, ~5 cm subsampled range) can be captured with few measurements and modest digitizer bandwidth, then unwrapped using surface-finding.

Litigation / CAFC check

• I found no CAFC 2026 docket, appeal, or IPR record naming US 11,320,256. My targeted searches for "11320256 CAFC Federal Circuit 2026" and for an infringement docket returned only unrelated Federal Circuit decisions (e.g., Arendi, Gramm v. Deere) and unrelated USPTO petition documents — none mentioning this patent.
• I cannot assert with confidence that no such proceeding exists. My litigation search was limited and did not return a docket-sheet source. A definitive negative would require a direct PACER/Docket Navigator or CAFC docket query, which I was unable to complete.

Residual uncertainty

• Exact granted claim language and claim count are not verified. I could not retrieve the issued claims pane; the overview above paraphrases the specification's summary section, which typically mirrors the independent claims but is not identical to them.
• The 11320256 vs. US 11,320,256 B2 formatting is preserved literally as given; I have not altered any identifier.
• PubChem's "Massachusetts Gen Hospital" and Google Patents' "General Hospital Corp" are treated as the same assignee (The General Hospital Corporation), not as distinct entities.

I'll search for litigation involving US patent 11320256 across patent litigation databases.

Let me refine my search with more specific patent litigation queries.

Let me check the specialized patent litigation databases directly.

Litigation Search Results — US Patent No. 11,320,256

Summary: I found no known litigation involving US Patent No. 11,320,256.

What I searched

I ran multiple targeted queries across general web indexes and patent-litigation-oriented sources, including attempts keyed to:

• The patent number both as 11320256 and as 11,320,256
• The patent title ("Apparatus and methods for high-speed and long depth range imaging using optical coherence tomography")
• The assignee/inventors (The General Hospital Corporation / Massachusetts General Hospital; Vakoc, Siddiqui) in a litigation context
• Unified Patents litigation resources, CourtListener/RECAP, and RPX litigation documents

What the searches returned (and why these are NOT this patent)

Every apparent "hit" on the number was a false positive for a different subject matter:

1. NHTSA complaint ID 11320256 — A Dodge Grand Caravan air-bag/minivan sliding-door consumer complaint. Not a patent at all.
2. Travis County (TX) payroll record "11320256" — An unrelated payroll/ACH entry.
3. Different patents referenced as "'156 Patent" and "'113 patent" — e.g., an Aegis/Maggio patent "No. 15/890,131 / '156 Patent" (a life-sciences patent), and "the '113 patent" in a Jet Dock / UMMG float-dock dispute. These are different patent numbers (note the '156 and '113 designations refer to other patents), not US 11,320,256.
4. General Hospital Corporation v. Sienna Biopharmaceuticals and General Hospital Corp. v. Esoterix Genetic Labs — These involve the same assignee, The General Hospital Corporation, but concern unrelated technologies (nanoparticle hair removal interference; a patent license/royalty contract dispute). They do not involve US 11,320,256.

Important caveats

• Per your instruction not to auto-correct identifiers, I treated 11320256 literally and did not substitute or conflate it with the similarly numbered "'113" or "'156" patents that appeared in search results. Those are distinct patents.
• I cannot rule out litigation with certainty. My search was limited (results were truncated before I could fully query Unified Patents' caselist, PACER, and RPX), and district-court complaints, ITC actions, and PTAB proceedings are not always fully indexed by general web search. A definitive negative requires a direct PACER/Docket Navigator/RPX/Unified Patents lookup by patent number, which I was unable to complete here.

Recommendation for a definitive answer

To confirm the absence (or existence) of litigation, verify directly via:

• Unified Patents litigation portal — https://portal.unifiedpatents.com/litigation
• PACER / CourtListener RECAP — search the patent number in the "Patent Case" query field
• USPTO PTAB (Patent Trial and Appeal Board) for any IPR/PGR involving 11,320,256
• USPTO Patent Assignment / PatentCenter for its current ownership (record shows The General Hospital Corporation), which can reveal assignments associated with enforcement

For the record (patent identification)

• Patent: US 11,320,256 B2 — "Apparatus and methods for high-speed and long depth range imaging using optical coherence tomography"
• Inventors: Benjamin Vakoc; Meena Siddiqui
• Assignee: The General Hospital Corporation
• Priority date: 2016-02-12; Filing: 2020-11-30; Granted: 2022-05-03
• Status (Google Patents listing): Active; anticipated expiration 2037-02-13

If you can supply or authorize a direct PACER/Docket Navigator pull, I can convert this "no litigation found" finding into a verified negative or identify any docketed case.

I'll start by checking the structured data's default against live sources, since ODP ingest can lag.

The first pass returned noise (an unrelated '856 patent from the iRhythm/Bardy dispute). Let me target the specific patent number and its family.

Let me probe a few more angles — PTAB docket databases, the related family member, and any litigation asserting this patent.

Proceedings overview

Total AIA trial proceedings on file for US 11,320,256: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceedings as of the most recent ingest, and my independent web searches surfaced no petition, institution decision, Final Written Decision, or Federal Circuit appeal involving this patent. Because there is nothing to break down by status (0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied), the defensive posture is the inverse of a hardened patent: all claims stand untested at the PTAB, so a defendant gets neither the benefit of a cancellation nor the burden of adverse estoppel findings — the entire invalidity case is still yours to build from scratch, with no prior petitioner's work product to borrow.

Note carefully what this does and does not mean. "No PTAB activity" is a statement about the AIA trial docket, not about patentability. It does not mean the claims are strong — it means nobody has paid to test them. It also does not mean the patent is unasserted or unlitigated; a patent can be litigated for years without attracting an IPR (patent owners frequently prefer district court, and defendants frequently prefer to save the $300k+ IPR cost).

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Proceedings

None to report. No proceeding-specific sections follow, because no proceeding exists on the record.

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What the searches did and did not show

I ran several targeted queries (patent number, patent number + PTAB, patent number + IPR, inventor names Vakoc/Siddiqui, assignee Massachusetts General Hospital / The General Hospital Corporation, and the family members US 12,013,572 B2 and US 2025/0044516 A1).

• No hit referenced US 11,320,256 in any AIA trial context.
• Several queries returned a different "…856 patent" — U.S. Patent No. 11,xxx,856 at issue in the iRhythm/Bardy dispute (cardiac monitoring) and an unrelated PGR on U.S. Patent No. 11,157,256 (Digital Turbine/ironSource), plus a PTAB FWD on U.S. Patent No. 10,562,680 (Tekni-Plex). None of these involve US 11,320,256. Per the operating rules I am not auto-correcting or conflating these numbers; they are simply noise, and I flag them so nobody downstream mistakes a search snippet for a proceeding against this patent.
• The '256 patent's technical family — stretched-pulse mode-locking, optically subsampled OCT, frequency-comb OCT (Siddiqui & Vakoc, Wellman Center for Photomedicine / MGH) — appears in the academic and conference literature (e.g., CLEO_AT-2017-AW4A.2), which is prior-art-adjacent material, not PTAB activity.

Confidence and caveats. I have high confidence in the "zero" figure because it is the canonical answer from the structured ODP block and my searches did not contradict it. My confidence is not absolute: ODP ingest lags, PTAB E2E filings are sometimes not indexed for days-to-weeks after filing, and PETITIONS filed very recently (e.g., within the last 4–8 weeks) may not yet be publicly retrievable. Before relying on this in a brief, verify at PTAB E2E (https://ptacts.uspto.gov/ptabweb/) and re-pull the ODP record.

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Strategic summary

Claim status. Because no claims have been challenged in an AIA trial, every claim of US 11,320,256 is UNTESTED. There are no canceled claims, no substitute claims from a motion to amend, and no claim-level estoppel on the record. For a defendant, this cuts both ways: you cannot knock out an asserted claim by citing a prior FWD (there is none), but you also face no § 315(e)(2) estoppel and no adverse panel construction that would constrain how you read the claims.

Estoppel landscape. With no IPR/PGR file history, no § 315(e)(2) estoppel attaches to anyone on this patent. Every prior-art ground — § 102 anticipation, § 103 obviousness, and § 112 written description/enablement — is fully available in district court and, if you file your own petition, in an AIA trial. Contrast this with a patent that has two FWDs behind it: there, the prior petitioners (and privies) would be locked out of grounds they raised or reasonably could have raised, often leaving a new defendant with a materially thinner invalidity case. Here that problem does not exist. Conversely, note that you would incur estoppel by filing and having a petition instituted — so the choice to file is a real strategic decision, not a free option, especially if parallel district court litigation is already underway.

Pattern signals. No petitioner has filed on this patent — not once, not repeatedly. No defensive aggregator (Unified Patents or similar) appears in the chain. No PTAB-to-CAFC appeal history exists. The practical read: US 11,320,256 has not been a priority target of the patent-challenge bar, even though it issued 2022-05-03 and its § 154(b)-adjusted / 20-year term runs to roughly 2037-02-13 (priority date 2016-02-12; the E2E listing shows an anticipated expiration of 2037-02-13). That is a long runway and a notable absence of third-party interest. It may reflect that the patent has not been broadly asserted against deep-pocketed defendants, or that the technology (high-speed optically subsampled OCT with a stretched-pulse mode-locked source) is used by relatively few commercial players.

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Recommended next steps

If you are a defendant:

1. Do not assume the patent is weak because no IPR was filed. The absence of PTAB activity tells you about other parties' incentives, not about claim strength. Commission your own prior-art search. The specification itself cites dense literature you can mine: the FWD-free path means the named references in the patent (e.g., Vakoc, Optics Letters 31(3) 362-364 (2006); Choma, Optics Letters 28(22) 2162-2164; Kim et al., Opt. Express 15, 18130-18140 (2007); Yezzi et al., IEEE Trans. Med. Imag. 16(2) 199-209 (1997)) and the applicants' own pre-2016 publications (e.g., the Siddiqui/Vakoc CLEO 2017 work and earlier SPML papers) are candidate § 102/§ 103 art.
2. Check the family, not just this patent. US 12,013,572 B2 and US 2025/0044516 A1 claim priority through the same chain. A petition against one family member may be stipulated away or precluded from covering the others, and claim scope across the family may differ — but the same prior art often reaches all of them. Any freedom-to-operate or invalidity opinion should address the family as a unit.
3. Weigh the IPR decision against § 315(e)(2) estoppel. If you file and the Board institutes, you forfeit in district court any ground you raised or reasonably could have raised. Consider whether your district court invalidity contentions already capture the best art; if so, an IPR may forfeit more than it wins. If parallel litigation exists and trial is scheduled before the projected FWD date, expect a Fintiv-style discretionary-denial fight under § 314(a) — note that the current regime (post-Fintiv-memo and the 2025 interim process guidance) makes general § 314(a) denials harder but keeps the longstanding NHK/Fintiv escape hatch alive when trial will clearly precede the FWD.
4. Verify the docket yourself before filing. Pull PTAB E2E (https://ptacts.uspto.gov/ptabweb/) and the ODP application record (https://patents.google.com/patent/US11320256/en and https://patents.google.com/patent/US20210080247A1/en) to confirm the "no proceedings" status on the day you rely on it.

If you are the patent owner: the zero-IPR record is a genuine asset. It means no claim has been canceled, no amendment has narrowed scope, and no panel has construed your terms adversely. Keep it that way by monitoring statutory bars — the one-year § 315(b) window runs from service of an infringement complaint, so a defendant you have sued has a clock running; a defendant you have merely sent a demand letter to does not.

Bottom line: there is no FWD to link to, no disposition to quote, and no panel to name, because there is no proceeding. The absence is a signal, but a weak one — it mainly tells you that this patent, unlike the heavily-IPR'd patents you may be used to seeing, has not yet been stress-tested at the Board.

I'll research the assignment chain for US 11,320,256, starting with the USPTO Patent Assignment Search and related sources.

Let me check Google Patents legal events and any related assignment records.

Ownership Chain Analysis — US Patent No. 11,320,256

Source limitation, stated up front: I was able to retrieve the Google Patents legal-events listing and other third-party mirrors (PubChem patent record, family member front pages), but I was not able to open assignmentcenter.uspto.gov directly — only a web-search tool was available to me, and targeted queries against the Assignment Center index returned no records. Consequently I can confirm the existence, date, parties, and conveyance type of the single recorded assignment, but not its reel/frame number or the correspondent of record. I will not invent those. Everything below is labeled accordingly.

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Inventors

Notes on unusual patterns:

• No departing-inventor pattern. Both named inventors appear as co-inventors on the same assignee's continuing family — US 9,668,652 ("System, apparatus and method for utilizing optical dispersion for Fourier-domain optical coherence tomography," Vakoc, Siddiqui, Tozburun; PCT filed 2014-07-25) and the later continuations US 12,013,572 and US 20 250 044 516. This is the signature of a stable, institution-anchored research group, not a portfolio being orphaned.
• Inventor list is narrower than the parent. Serhat Tozburun appears on US 9,668,652 but not on 11,320,256. That is routine continuation-inventorship trimming, not attrition preceding a sale.
• Both inventors are the assignors on the sole recorded assignment (see below), so there is no inventor-side retained-interest red flag.

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Original assignee

• Entity on the issued patent: The General Hospital Corporation (d/b/a Massachusetts General Hospital), Boston, MA. PubChem's mirrored record lists the assignee as "MASSACHUSETTS GEN HOSPITAL (US)" — the same entity under its common name.
• Line of business: Operating nonprofit academic medical centre and research institution; the patent emerged from its Wellman Center for Photomedicine. This is a hospital/university research organization, not a licensing vehicle.
• Product embodying the claims: The claimed subject matter is an OCT laser/circular-ranging imaging architecture. Mass General does not commercialize hardware directly; the work was published academically (the Nature Photonics 2018 stretched-pulse mode-locked / compressed-sensing OCT work, whose supplementary material describes the same 200 GHz-FSR SPML laser and 543 µm baseband depth cited in the patent's own FIGS. 13–16 discussion). Any commercial embodiment would be licensed, not sold, by MGH.
• Current status: Operating. The parent health system (Mass General Brigham) remains an active, solvent nonprofit. No bankruptcy, dissolution, or acquisition of the assignee is on record.
• Current owner per Google Patents: still The General Hospital Corporation; status "Active," anticipated expiration 2037-02-13.

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Assignment timeline

Recorded assignment(s) on file: one.

• 2020-12-01 (recorded) / execution date not exposed in the fetched record — Reel/frame not retrievable from the sources I could access (see source limitation above).
  • Conveyance: Assignment of assignors' interest ("ASSIGNMENT OF ASSIGNORS' INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Siddiqui, Meena; Vakoc, Benjamin
  • Assignee: The General Hospital Corporation
  • Correspondent: Not determinable from the retrieved record. This is the one field the task specifically flags as the NPE "tell," and I cannot supply it without fabricating. It should be pulled directly from the reel/frame image at the Assignment Center; for an academic medical centre this is typically institutional tech-transfer counsel, but I will not assert a name.
  • Context: Original inventor-to-institution assignment — the standard employer/employee (or sponsored-research) title-capture recordation. It was recorded the day after the 2020-11-30 filing of application 17/106,690, i.e., contemporaneous with the continuation filing rather than any third-party transfer.

No post-issuance assignments exist in the record I could retrieve. There is no assignment to any LLC, no security agreement, no merger, no change of name, and no license recorded against the patent. Google Patents' legal-events table shows only: application filed (2020-11-30) → assignment to The General Hospital Corporation (2020-12-01) → publication US 20 210 080 247 A1 (2021-03-18) → grant (2022-05-03) → priority claim to continuations US 12,013,572 (2022-03-30) and US 20 250 044 516 (2024-05-22).

Family context (not separate assignments to this patent, but relevant to the ownership story): the same assignee filed and owns the sibling/continuing members — US 9,668,652, US 12,013,572, US 20 250 044 516, and EP 3 935 343 (all "The General Hospital Corporation"). A single institutional owner prosecuting a long continuation chain is the opposite of a fire-sale signature.

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Timeline diagram

timeline
    title Ownership of US 11320256
    2016 : Priority date 12 Feb 2016
    2017 : Parent PCT application filed
    2020 : Continuation filed 30 Nov 2020
         : Inventors assign to General Hospital Corp
         : Assignment recorded 01 Dec 2020
    2022 : Patent granted 03 May 2022
         : Child continuation claimed priority
    2024 : Further continuation claimed priority

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NPE / troll-pattern signals

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Verdict

Insufficient data — only the original inventor-to-institution assignment is on record, and I was unable to retrieve its reel/frame or correspondent.

Justification: the sole recorded conveyance is the 2020-12-01 assignment of Siddiqui's and Vakoc's rights to The General Hospital Corporation, recorded one day after the 2020-11-30 filing of application 17/106,690 — a routine institutional title-capture, not a transfer to an asserter. There is no post-issuance assignment, no LLC, no known NPE, no cascading transfer, no bankruptcy sale, and (per the prior section of this analysis) no litigation, so every affirmative NPE signal is either absent or untestable. The practical reading is original-assignee-retained / non-asserting: one of the world's largest hospital research institutions still owns the patent and is actively extending the family (US 12,013,572; US 20 250 044 516), which is inconsistent with troll behaviour — but because I could not confirm the reel/frame and correspondent, "insufficient data" is the honest formal call rather than a clean "non-asserting" one.

Verification links:

• USPTO Assignment Center (search patent number 11320256): https://assignmentcenter.uspto.gov/
• Legacy Assignment Search: https://assignment.uspto.gov/patent/index.html
• Google Patents legal events for this patent: https://patents.google.com/patent/[US11320256B2](/patent/US11320256B2)/en

Single outstanding gap to close: pull the reel/frame image for the 2020-12-01 recording at the link above and read off (a) the reel/frame and (b) the correspondent of record. If that correspondent also appears across the MGH OCT family (US 9,668,652; US 12,013,572; US 20 250 044 516), it merely confirms institutional tech-transfer counsel — and if any future recording shows a different attorney picking up the family, that is the event that would warrant re-running this analysis.

I'll research the specific prior art cited on the face of US Patent No. 11,320,256 and its family, focusing on the references that actually appear in the patent's citation records.

Let me pull the actual front-page "References Cited" list for this specific patent and its family member, and check the related application.

Let me retrieve the patent's actual front page and cited-references via the USPTO/Google Patents PDF.

Prior-Art Analysis — US Patent No. 11,320,256 B2

1. The patent, identified literally

I was asked to analyze US 11,320,256 — interpreted literally, not conflated with the similarly numbered "’113," "’156," or "’256" shorthand references that surface in other dockets.

• Number: US 11,320,256 B2 (application 17/106,690; pub. US 2021/0080247 A1)
• Title: "Apparatus and methods for high-speed and long depth range imaging using optical coherence tomography"
• Inventors: Benjamin Vakoc; Meena Siddiqui
• Assignee: The General Hospital Corporation (Boston, MA)
• Priority: 2016‑02‑12 (provisional 62/294,822); also 62/310,365 (2016‑03‑18)
• Continuity: continuation of 16/077,294 (now US 10,852,121), which is the U.S. national phase of PCT/US17/17664 (pub. WO 2017/139760 A1)
• URL: https://patents.google.com/patent/US11320256/en

2. Important limitation on this analysis (read first)

I could not retrieve the patent's front-page "(56) References Cited" list through the available search tools. The Google Patents mirror for this record (returned in my searches) exposes the description and classifications but did not return the examiner-cited U.S. patent documents, foreign patent documents, or the "Other Publications"/NPL block that normally appears on the front page. Multiple targeted queries for the (56) block returned the citation lists of other patents (US 10,327,767; US 11,344,413; US 8,764,326; etc.) rather than US 11,320,256.

Therefore:

• What I can ground with high confidence is (a) the prior-art references cited within the specification/description of US 11,320,256 itself (these are in the authoritative full text you supplied), and (b) the family/sibling relationships.
• I cannot represent that the list below is the complete examiner-cited (56) record. A definitive (56) list requires a direct pull of the patent PDF front page or PatentCenter/Global Dossier for US 17/106,690. I will flag this explicitly rather than invent references.

I will not fabricate reference numbers, dates, or passages I could not verify.

3. References cited within US 11,320,256 (confirmed from the patent text)

These are the prior-art citations appearing in the specification of the patent. Effective U.S. filing/priority is 2016‑02‑12, so each is analyzed against that date. None of these was retrieved as an examiner-cited (56) entry; they are applicant/specification citations.

Key point for § 102: none of references 1–6, alone, discloses all elements of the flagship independent claim (the laser apparatus of claim 1, reciting a laser arrangement with an optical cavity comprising a dispersive optical waveguide first arrangement having first/second sides, receiving first radiation at the first side and third radiation at the second side, plus an active optical modulator second arrangement). They are individually directed to detection, scanning, image processing, or sub-sampling — i.e., they are more properly cited under § 103 in combination, and would support § 102 only against narrower dependent/method claims (demodulation, scanning, surface-finding, error-correction).

4. Family / sibling references — flagged, but generally NOT prior art

A recurring source of error is treating the patent's own family as prior art. Note these explicitly:

• US 10,852,121 B2 — the parent of US 11,320,256 (continuation). Not prior art under § 102 to the same applicant's later continuation.
• US 2022/0221267 A1 and US 12,013,572 B2 (application 17/708,143, filed 2022‑03‑30) — later continuations of the same ’256 disclosure. Not prior art.
• US 2021/0080247 A1 — the pre-grant publication of the ’256 application itself. Not prior art.

However, one sibling family warrants a § 102 review flag: the General Hospital Corporation family entitled "System, apparatus and method for utilizing optical dispersion for Fourier-domain optical coherence tomography" (US 2019/0082962 A1 and US 2020/0345235 A1), which claims priority to US provisional 61/858,808, filed 2013‑07‑26 — i.e., earlier than the ’256 priority date. That disclosure recites a laser cavity with dispersive first/third arrangements and an active optical modulator second arrangement producing spectral filtering, with the wavelength controlled by the dispersion. It is the closest same-assignee analogue to the ’256 laser claims and should be checked against the ’256 cavity claims under § 102(a)(2)/(e), subject to the § 102(b)(2)(C) common-ownership exception. I could not verify from the tools whether it was cited in the ’256 prosecution.

5. Forward citations (explicitly NOT prior art)

The same Google Patents pages returned listings such as US 11,684,242 B2 (Gentuity), US 11,408,722 B2 (Panasonic), WO 2023/023017 A1 (Spectrawave), and CN 109073356 A/B (the Chinese family member). These are "Cited By"/family entries — i.e., later documents citing the ’256 family, or its own family members. They have no § 102 relevance.

6. § 102 summary judgment

• Single-reference anticipation of the independent laser-cavity claim 1: not established by any reference I could verify. No confirmed reference discloses the full combination of (i) a bidirectional dispersive waveguide in the cavity, (ii) an active optical modulator receiving the returned radiation, and (iii) the resulting >80 nm/µs wavelength-change rate or >20 M steps/s discrete-frequency stepping recited in the dependent claims.
• Strongest § 102 exposure (for narrower claims): the inventors' own Siddiqui, Optics Express 23(5):5508–5520 (2015) (optical subsampling + quadrature error correction) and the Vakoc ’743 publication / Vakoc Optics Letters 2006 (polarization demodulation).
• Likely § 103 clusters: (Siddiqui 2015 + Sidor/dispersive-cavity art) for the laser claims; (Choma 3×3 + Vakoc) for demodulation claims; (Kim MEMS scanner) for the beam-scanning claims; (Yezzi snake model) for the surface-unwrapping method claims.

7. Caveats and recommended verification

• I did not retrieve the actual (56) front-page reference list of US 11,320,256, and I will not simulate it. The citations above are those confirmed inside the patent text; the examiner-cited patent documents (U.S. and foreign) are still unverified.
• To complete a true "each patent citation" analysis, pull directly:
  • USPTO PatentCenter for application 17/106,690 (form PTO/SB/08A/08B and the examiner's "Notice of References Cited"),
  • the patent PDF front page (patentimages/Google Patents),
  • Global Dossier / Espacenet for the PCT/US17/17664 ISR and the EP/CN counterparts' search reports.
• Until that pull is done, treat the § 102 mapping above as provisional and limited to the specification-cited references.

If you authorize a direct PatentCenter/Global Dossier lookup (or paste the patent's (56) block), I can convert this into a complete, reference-by-reference § 102/§ 103 chart with verified numbers and dates.

I'll first try once more to retrieve the actual granted claim text, since a §103 analysis must be anchored to claim language rather than to the specification's "summary of embodiments" passages. Then I'll build the obviousness analysis on the prior-art foundation already established.

Key finds: an EPO search-opinion document that paraphrases the claim-1 architecture of the EP family member, and the inventors' own 2014 Tozburun paper. Let me firm up the dispersion-tuning and stretched-pulse prior art, plus the same-assignee dispersion patent.

Obviousness Analysis — US 11,320,256 B2 under 35 U.S.C. § 103

Building on: the Prior Art section above (which established the specification-cited references: Vakoc Opt. Lett. 31(3):362–364 (2006); US 2007/0035743; Choma Opt. Lett. 28(22):2162–2164 (2003); Kim Opt. Express 15:18130 (2007); Yezzi IEEE TMI 16(2):199–209 (1997); Siddiqui Opt. Express 23(5):5508 (2015)). I do not repeat that mapping here; I extend it.

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1. A better claim-scope proxy than the "summary of embodiments"

The prior sections flagged that the granted US claim text was never retrieved. This round I found an EPO search-opinion document (EP 3 414 518 A4) that paraphrases claim 1 of the European sibling of this family in language that tracks the '256 disclosure nearly verbatim:

"Laser device with an optical cavity comprising: a dispersive waveguide receiving a first electro-magnetic radiation at a side to provide a second electro-magnetic radiation, and a third electro-magnetic radiation at a different side to provide a fourth electro-magnetic radiation, the second and third radiations being related to one another; an active optical modulator receives and modulates the fourth radiation to provide the first electro-magnetic radiation to the waveguide; the laser device outputs one of the first, second, third or fourth radiation. Dependent claims 2-10 deal with details of the dispersive waveguide, define an optical amplifier and an optical polarizer filter."
— EP 3 414 518 A4, Search Division opinion, https://patentimages.storage.googleapis.com/07/cc/8e/edaa2aeb33d4c5/EP3414518A4.pdf

Flag: this is the EP claim set, and my inference that EP 3 414 518 is the regional-phase counterpart of this family's PCT is based on the near-verbatim identity of the radiation-naming scheme — not on a retrieved priority link. Treat it as a high-quality proxy, not as US claim 1. Everything below is written to the architecture (bidirectional dispersive waveguide + intracavity active modulator), which is common to both.

2. POSITA

A person of ordinary skill as of 2016‑02‑12: an M.S. or Ph.D. in optics, electrical engineering, or biomedical engineering with 2–4 years of hands-on fiber-laser and/or OCT system development, or a B.S. with 5+ years of equivalent experience. That person knows without prompting: (i) FBG/chirped-FBG dispersion engineering; (ii) active mode-locking and harmonic cavity drive; (iii) FDML and dispersion-tuned swept sources; (iv) OFDI/SD-OCT interferometry, quadrature detection and complex-conjugate suppression; and (v) galvanometric/MEMS beam scanning.

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3. Ground 1 — The laser-cavity apparatus claims (§ 103)

3.1 The primary reference a POSITA would actually start from

Tozburun, Siddiqui & Vakoc, "A rapid, dispersion-based wavelength-stepped and wavelength-swept laser for optical coherence tomography," Opt. Express 22(3):3414–3424 (2014-02-10) — https://pubmed.ncbi.nlm.nih.gov/24663631/

Abstract (as retrieved): "Optical-domain subsampling requires a wavelength-stepped rather than a wavelength-swept source… introduces a novel design for a rapid wavelength-stepped laser source that uses dispersive fibers in combination with a fast lithium-niobate modulator to achieve wavelength selection. A laser with 200 GHz wavelength-stepping and a sweep rate of 9 MHz over a 94 nm range at a center wavelength of 1550 nm is demonstrated. A reconfiguration of this source design to a continuous wavelength-swept light for conventional Fourier-domain OCT is also demonstrated."

This single reference discloses the entire purpose, architecture family and operating band of the '256's laser claims: dispersive fiber in a laser cavity, a fast LiNbO₃ modulator performing wavelength selection, 200 GHz discrete wavelength stepping, 9 MHz rate, 94 nm at 1550 nm. It is also, functionally, the laser of the '256's own FIG. 6 (positive/negative dispersion compensating fiber + intensity modulator + FP etalons + SOA).

Status check (important, and favorable): published 2014‑02‑10, i.e. more than one year before the 2016‑02‑12 priority date. Under AIA § 102(a)(1) it is prior art, and the § 102(b)(1)(A) inventor grace-period exception is unavailable on timing alone (it protects only disclosures made ≤1 year before the effective filing date). This is the cleanest piece of art in the whole analysis, and it is the applicants' own work.

3.2 The gap in Ground 1 and how it is filled

Tozburun 2014 uses two separate dispersive fibers (a negative-DCF and a positive-SMF path — exactly as the '256 describes its own FIG. 6). The asserted claim 1 requires a single dispersive arrangement having two different sides, addressed from each side.

Filling reference: US 6,292,603 ("BiDCG" — bidirectional dispersion compensation grating). As retrieved from the patent text:

"…a light component with a shorter wavelength… is reflected from a point in the chirped grating fiber 6 that is close to the first optical circulator 7a… the lightwave signal input via the first input terminal 2 is positively dispersed. On the other hand, a lightwave signal… input to the BiDCG 1 by way of the second input terminal 4… is negatively dispersed… the BiDCG 1… can provide dispersion compensations of the same absolute amount but of opposite sign for both two different input lightwave signals, respectively, using the single chirped grating fiber 6. Accordingly, the space required for mounting the BiDCG 1 and the manufacturing cost can be reduced largely as compared with… a prior art DCG."

That is a literal teaching of the "first side / second side, second and third radiations related to one another" limitation — including the express motivation (fewer parts, less space, lower cost) that KSR requires. US 6,292,603 (content verified from the patent PDF; I did not independently verify its exact issue date — the number indicates a 2001 grant).

3.3 Secondary/corroborating references for the same ground

3.4 Ground 1 conclusion and the dependent claims

Claim 1 (in the EP proxy form) reads on Tozburun 2014 + US 6,292,603. Reasonable expectation of success is high because each reference was an experimentally reduced-to-practice fiber laser, and the combination merely replaces two single-ended dispersive fibers with one doubly-addressed grating — a substitution of one known element for another known to perform the same function, with a stated cost/space advantage.

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4. Ground 2 — Laser + interferometer + beam scanner ("3D measurement") claims

Combination: Tozburun 2014 (+ US 6,292,603) + an OFDI interferometer + a scanner.

• Motivation is explicit in the reference itself. Tozburun 2014's stated purpose is "Fourier-domain OCT imaging at high-speeds and extended depth ranges." A POSITA does not need to be told to place an OCT source in an OCT interferometer — sample arm, reference arm, recombination and detection are the definitional elements of the system the paper is addressing.
• Interferometer/demodulation: Vakoc Opt. Lett. 2006 and US 2007/0035743 (polarization-based complex demodulation) and Choma 2003 (3×3 coupler) supply the sample-arm/reference-arm interference measurement and the complex signal recovery.
• Scanner: Kim 2007 supplies a MEMS beam scanner; the '256's own FIG. 12 microscope uses ordinary galvanometers, which are the most routine scanning choice in the field. Motivation: obtaining a 3D dataset from a 2D scan is the standard OCT mode of operation (FDML 2006 demonstrated 3.5 volumes/s in 2006).
• Two dispersive elements, or two parts of one FBG (the alternative in the summary): obvious in view of the BiDCG single-grating teaching and of the '250 family.

Where this ground is strongest: the "3D measurement of an optical property" limitation is the ordinary output of a conventional OCT system; there is no synergy or unexpected result created by the combination.

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5. Ground 3 — The discrete-frequency / comb-source claims

Recitations: N discrete optical frequencies; linewidth <10 GHz**; spacing **>20 GHz; stepping >20 million steps/s; FBG or FBG array longer than 2 m.

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6. Ground 4 — Real-time (<1 s latency) video display and interactive medical guidance

Combination: FDML (2006) + Tozburun 2014 + Kim 2007 + Yezzi 1997 + WO 2009/036861.

• <1 second latency. FDML (2006) already reported 906 frames/s and 3.5 volumes/s and explicitly framed the goal as "high imaging speeds and large imaging depths." When the acquisition is an order of magnitude faster than a video frame, a sub-second measurement-to-display latency reduces to ordinary pipelined and parallelized signal processing — a predictable engineering result, not an inventive one. The '256 concedes the point: "because the speed of such exemplary laser far exceeded the scanning speed, it was possible to average adjacent A-lines."
• Interactive guidance during a medical procedure. This is a purpose limitation. WO 2009/036861 ("Method and measuring device for gauging surfaces") expressly teaches using the interferometric amplitude-vs-wavelength signature as a control variable to reposition the probe — i.e., closing a measurement→actuation loop on the source's output — and describes the source as a fiber ring laser with an SOA and tunable filter operated "in FDML mode" with reference to Huber 2006. Kim 2007 supplies the endoscopic delivery. Motivation: a surgeon manipulating tissue needs the feedback loop the reference already describes for a coordinate-measuring machine; the medical analogue is a predictable application.
• "Measurement performed using a frequency comb optical source" / the Ground-1 laser: both covered above.

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7. Ground 5 — 4D→2D compression controlled by a located surface

Combination: Yezzi 1997 + Siddiqui 2015 + Kim 2007.

• Yezzi supplies surface finding by active contours; the specification cites it for exactly that.
• Compressing one spatial dimension conditioned on the detected surface is the standard "surface flattening" visualization (routine in retinal OCT). The '256 describes it in the same functional terms: locate the surface and unwrap "to generate an image where the tissue is shown with a surface that is approximately constant in depth."
• Motivation: without flattening, an en face projection smears across depth; with it, projection images are anatomically meaningful (the reference's own images 1503–1507, 1601). This is a predictable, conventional data-processing step with no asserted unexpected result.

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8. Motivation-to-combine ledger (KSR rationales, consolidated)

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9. Where the obviousness case is weak — and the counterarguments to expect

1. The >20 M steps/s recitation is not met by the best art. Tozburun 2014 is 9 MHz. This is the one numeric recitation that plausibly carves out the claim from the inventors' own earlier paper, and a patent owner will hammer it. Counter: the specification itself treats the rate as electronically selectable by harmonic order — but expect a "claim a number just above your own prior work" obviousness/§ 112 fight.
2. Common ownership may neutralize the '250/'652 family. Both are The General Hospital Corporation. If those disclosures are available only as § 102(a)(2) art (filed-before, published-after), the § 102(b)(2)(C) / pre-AIA § 103(c) common-ownership exception removes them from both § 102 and § 103. The Tozburun 2014 journal article, by contrast, is § 102(a)(1) art and cannot be excepted. Do not build the case on the '250 family alone.
3. Contradiction to flag with the earlier Prior Art section (per my instructions). That section characterized Siddiqui Opt. Express 23(5):5508 (2015) as "§ 102(b) art" because it is ">1 yr before priority." Two problems: (a) under the AIA (this patent's effective date is 2016, post-March-2013), there is no one-year "102(b)" bar — the provision is § 102(a)(1) subject to the § 102(b)(1)(A) grace-period exception; (b) Optics Express vol. 23, issue 5 publishes in early March 2015, which is less than one year before 2016‑02‑12. If the disclosure is the inventors' own (it is — Siddiqui and Vakoc), the exception is arguably available. Practical consequence: the single best anticipatory reference for the OS-OCT/depth-aliasing and quadrature/spectral error-correction subject matter may be disqualified, which materially weakens the § 102 case against the demodulation and error-correction claims and shifts weight onto Tozburun 2014 and the general error-correction literature. Resolve this before relying on Siddiqui 2015.
4. Numeric thresholds as potential secondary considerations. A patent owner may argue the <10 GHz / >20 GHz / >20 MHz / >2 m / <1 s values reflect unexpected results. The specification undercuts this by describing each as a design choice with stated trade-offs.
5. No objective indicia on record. Per the earlier sections, there is no litigation, no IPR, and no licensing evidence — so no nexus evidence of commercial success, long-felt need or industry praise exists to rebut the prima facie case. That cuts against the patent owner, not for them.

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10. Bottom line

Strongest available single reference: Tozburun, Siddiqui & Vakoc, Opt. Express 22(3):3414 (2014) — same inventors, same assignee, same problem, and outside the grace period.
Weakest link in the case: the >20 million steps/second recitation.
Most consequential unresolved issue: whether Siddiqui 2015 falls inside the AIA grace period (contradicting the earlier section's characterization), and whether the common-ownership exception removes the '250/'652 family from the § 103 analysis.

Verification still required before filing anything: (1) the actual granted US claim set for 17/106,690 via PatentCenter/Global Dossier — everything above is keyed to the EP proxy; (2) the U.S. (56) reference list, which the prior sections could not retrieve; (3) the exact publication date of Opt. Express 23(5); (4) confirmation of the US 6,292,603 issue date and assignee; (5) confirmation of the Tamura/Ippen/Haus stretched-pulse citation, which is training-derived and unverified this session.