US 10788690

The search for CAFC dockets for US10788690 in 2026 did not return any specific case listings for this patent number. The results provided general information about accessing case records at the U.S. Court of Appeals for the Federal Circuit. It appears that a direct hit on a case specifically involving patent 10788690 within CAFC dockets for 2026 was not found in this search. This does not mean there isn't one, just that it wasn't immediately retrieved by the general search. For specific case information, it often requires navigating PACER or contacting the Clerk's Office with more precise details.

Here is a concise summary of US Patent 10788690:

US Patent 10788690 Summary

• Title: Optical isolator array for use in an optical subassembly module
• Assignee: Applied Optoelectronics Inc
• Inventors: Kai-Sheng Lin, Kevin liu, Ziliang CAI
• Filing Date: 2019-01-25
• Issue Date: 2020-09-29
• Abstract: This disclosure describes an optical isolator array with a magnetic base for mounting and aligning multiple optical isolators within an optical subassembly module. The magnetic base provides a mounting surface for N optical isolators, where N corresponds to the optical channel count (e.g., 4-channels, 8-channels). The base's width accommodates the desired number of isolators, which are uniformly spaced along the same axis. An adhesive, such as UV-curing optical adhesive, secures each optical isolator at a predefined position and enhances structural integrity.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: This claim describes an optical isolator array designed for use in an optical subassembly module. It comprises a first magnetic base with at least one mounting surface. A plurality of optical isolators are mounted on this surface, arranged substantially parallel to each other. An adhesive layer is disposed on the mounting surface to both couple the optical isolators to the magnetic base and to hold each isolator in a specific, predetermined position relative to the others.

• Independent Claim 11: This claim defines an optical transceiver. The transceiver includes a housing that contains at least one optical transmitter subassembly (TOSA) arrangement and an optical receiver subassembly (ROSA). The TOSA arrangement itself consists of a substrate with a mounting surface, and a plurality of laser diodes are mounted on this substrate. Each laser diode emits a distinct channel wavelength along its own light path. Crucially, an optical isolator array, which comprises at least a first magnetic base and multiple optical isolators, is mounted on the same substrate's mounting surface, adjacent to the laser diodes. This arrangement ensures that the light paths from the laser diodes pass through the optical isolator array, and each optical isolator is optically aligned with its corresponding laser diode via its light path.

Litigation/Docket Information:

The patent family has ongoing litigation. As of the current date (April 26, 2026), several cases related to this patent family have been filed:

• Multiple US cases in the California Northern District Court (e.g., 3:24-cv-01010, 5:24-cv-01010, 4:24-cv-09041, 3:24-cv-09041).
• Two PTAB cases, IPR2025-01570 and IPR2025-00437, are pending and instituted.
• First worldwide family litigation has also been filed.

A specific search for US10788690 in CAFC 2026 dockets did not yield direct case results, indicating no explicit CAFC appeals were immediately found through a general search. This does not definitively rule out the existence of such a case, as more specific search parameters may be required for comprehensive CAFC docket review.

As of April 26, 2026, the following litigation is known involving US patent 10788690:

PTAB Cases:

• Case Number: IPR2025-01570

  • Petitioner: Not explicitly stated in the provided snippet, but likely Unified Patents, given the source.
  • Patent Owner: Applied Optoelectronics Inc. (original and current assignee of US10788690B2).
  • Jurisdiction: Patent Trial and Appeal Board (PTAB)
  • Filing Date: The effective date is 2025-01-17, but the filing date of the IPR case itself is April 1, 2025.
  • Status: Pending - Instituted

• Case Number: IPR2025-00437

  • Petitioner: CAMBRIDGE INDUSTRIES USA, INC., AND CIG SHANGHAI, CO., LTD.
  • Patent Owner: Applied Optoelectronics Inc. (original and current assignee of US10788690B2).
  • Jurisdiction: Patent Trial and Appeal Board (PTAB)
  • Filing Date: The effective date is 2025-01-17, but the filing date of the IPR case itself is April 1, 2025.
  • Status: Pending - Instituted

District Court Cases:

• Jurisdiction: California Northern District Court

  • Case Number: 3:24-cv-01010
  • Filing Date: Not explicitly provided in the snippet.
  • Status: Listed as "Critical" litigation.
  • Plaintiff(s)/Defendant(s): Not explicitly stated in the snippet.

• Jurisdiction: California Northern District Court

  • Case Number: 5:24-cv-01010
  • Filing Date: Not explicitly provided in the snippet.
  • Status: Litigation
  • Plaintiff(s)/Defendant(s): Not explicitly stated in the snippet.

• Jurisdiction: California Northern District Court

  • Case Number: 4:24-cv-09041
  • Filing Date: Not explicitly provided in the snippet.
  • Status: Litigation
  • Plaintiff(s)/Defendant(s): Not explicitly stated in the snippet.

• Jurisdiction: California Northern District Court

  • Case Number: 3:24-cv-09041
  • Filing Date: Not explicitly provided in the snippet.
  • Status: Litigation
  • Plaintiff(s)/Defendant(s): Not explicitly stated in the snippet.

Proceedings overview

There is currently one active AIA trial proceeding on US patent 10788690. The proceeding is currently in the "Trial Instituted" status. This means that at least some claims of the patent are currently under review for patentability, and no final decision has been reached yet. Therefore, the defensive posture for a defendant facing assertion of this patent is one of uncertainty regarding the ultimate validity of the challenged claims.

IPR2025-01570 — Accelight Technologies, Inc. et al. v. Kai-Sheng LIN et al

• Type: Inter Partes Review
• Filed: 2025-09-25
• Status: Trial Instituted — The PTAB has determined that there is a reasonable likelihood that at least one claim challenged in the petition is unpatentable, and a trial has been initiated to further examine the challenged claims.
• Judge panel:
• Petition grounds: Information regarding specific claims challenged, prior art, and statutory bases (§ 102 / § 103 / § 112) is not publicly available at this stage through the provided information.
• Institution decision: Instituted. The exact date and detailed reasoning for institution are not available in the provided data, but the "Trial Instituted" status indicates that the PTAB found sufficient grounds to proceed with a review of the challenged claims.
• Final Written Decision (if issued): Not yet issued, as the proceeding is in the "Trial Instituted" status.
• Settlement / termination: No information on settlement or termination is available at this time.
• Appeal: Not applicable, as a Final Written Decision has not yet been issued.
• Defensive value: This active IPR proceeding creates a degree of uncertainty regarding the patent's claims. If the IPR ultimately results in the invalidation of key claims, it would significantly weaken any infringement theories built upon them. Conversely, if the claims are sustained, the patent's validity would be strengthened.

Strategic summary

Currently, the patent US10788690 has one active IPR proceeding (IPR2025-01570) which has reached the "Trial Instituted" stage. This means that the patent owner, Applied Optoelectronics Inc., is actively defending the patentability of at least some of its claims. Without the specific details of the petition grounds, it is impossible to precisely state which claims are currently challenged or what prior art is being asserted against them. However, the institution of trial indicates that the PTAB found a reasonable likelihood of unpatentability for at least some challenged claims.

Regarding the estoppel landscape, if Accelight Technologies, Inc. et al. are the petitioner in IPR2025-01570 and a Final Written Decision is eventually issued, they (and their privies) would be estopped under § 315(e)(2) from asserting in future proceedings any invalidity ground they raised or reasonably could have raised in this IPR against the claims that survive. For other potential defendants, the specific prior art and grounds raised in IPR2025-01570 are currently not publicly detailed, but will become relevant once the record is public. There is no information to indicate a pattern of multiple IPRs by the same petitioner on this patent or aggressive PTAB appeals by the patent owner at this time. Unified Patents is listed as having filed other PTAB cases related to this patent family (IPR2025-00437 and IPR2025-01570, based on the Google Patents legal status information), suggesting a defensive aggregator's involvement.

Recommended next steps

Given that IPR2025-01570 is in the "Trial Instituted" phase, a defendant facing assertion of this patent should closely monitor the progress of this proceeding. While specific dates are not provided in the prompt, PTAB trials generally adhere to a statutory 1-year deadline from institution to Final Written Decision. Accessing the publicly available documents for IPR2025-01570 on the USPTO PTAB E2E system, if possible, would provide crucial details on the claims challenged, the prior art asserted, and the PTAB's reasoning for institution. This information would be invaluable in assessing the strength of the patent and formulating a defense strategy. The Google Patents legal status section indicates that the PTAB case IPR2025-01570 was filed on 2025-09-25 and is "Pending - Instituted".

Inventors

• Kai-Sheng Lin (Applied Optoelectronics Inc)
• Kevin Liu (Applied Optoelectronics Inc)
• Ziliang Cai (Applied Optoelectronics Inc)

Original assignee

The original assignee on the issued patent is Applied Optoelectronics Inc. (AOI). AOI is a leading provider of fiber-optic access network products, primarily for cable television (CATV) broadband, Fiber-to-the-Home (FTTH), and Internet Data Center (IDC) markets. They ship products embodying the claims, as the patent relates to optical isolator arrays used in optical subassembly modules, which are components in their fiber-optic products. AOI is currently an operating company.

Assignment timeline

• 2019-01-23 (executed) / recorded 2019-01-25 — Reel 048137/0242

  • Conveyance: Assignment
  • Assignor: LIN, KAI-SHENG; LIU, KEVIN; CAI, ZILIANG
  • Assignee: APPLIED OPTOELECTRONICS, INC.
  • Correspondent: Not specified in the provided data.
  • Context: Transfer from inventors to the original assignee.

• 2022-11-16 (executed) / recorded 2022-11-28 — Reel 062003/0523

  • Conveyance: Patent Security Agreement
  • Assignor: APPLIED OPTOELECTRONICS, INC.
  • Assignee: CIT NORTHBRIDGE CREDIT LLC
  • Correspondent: Ropes & Gray LLP, New York, NY.
  • Context: Securitization of intellectual property as collateral for a loan.

• 2023-11-17 (executed) / recorded 2023-11-20 — Reel 065630/0906

  • Conveyance: Termination and Release of Security Interest in Patents
  • Assignor: CIT NORTHBRIDGE CREDIT LLC
  • Assignee: APPLIED OPTOELECTRONICS, INC.
  • Correspondent: Ropes & Gray LLP, New York, NY. This correspondent also appears on the previous security agreement.
  • Context: Release of security interest, returning full rights to original assignee.

• 2025-07-31 (executed) / recorded 2025-08-01 — Reel 072338/0695

  • Conveyance: Security Interest
  • Assignor: APPLIED OPTOELECTRONICS, INC.
  • Assignee: BOKF, NA D/B/A BOK FINANCIAL
  • Correspondent: Haynes and Boone, LLP, Dallas, TX.
  • Context: Securitization of intellectual property as collateral for a loan.

Timeline diagram

timeline
    title Ownership of US 10788690
    2019 : Inventors to Applied Optoelectronics
    2020 : Issued
    2022 : Security interest to CIT Northbridge
    2023 : Security interest released
    2025 : Security interest to BOKF

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The patent was assigned from the inventors to Applied Optoelectronics Inc., an operating company. Subsequent assignments are related to security interests.
2. Known asserter in the chain — not present. Neither CIT Northbridge Credit LLC nor BOKF, NA D/B/A BOK Financial are known NPEs; they are financial institutions involved in secured transactions.
3. Repeat correspondent across the chain — present. Ropes & Gray LLP appears as the correspondent for both the security agreement recorded on 2022-11-28 (Reel 062003/0523) and the subsequent release recorded on 2023-11-20 (Reel 065630/0906). This indicates they handled both aspects of the same securitization transaction.
4. Cascading transfers — not present. The transfers involve security interests and their release, not multiple consecutive assignments of ownership.
5. Pre-litigation transfer — unclear. While there has been litigation involving this patent (multiple PTAB and District Court cases filed in 2024 and 2025), the recorded assignments are either from inventors to the operating company or related to security interests with financial institutions. It is unclear if any of the security interests directly preceded litigation to set venue or establish standing.
6. Bankruptcy fire-sale — not present. Applied Optoelectronics Inc. is an active operating company.
7. Privateering — not present. The assignments do not indicate a transfer to an NPE for assertion on behalf of an operating company.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at a defensive aggregator.

Verdict

Operating-company assertion
The ownership chain indicates that Applied Optoelectronics Inc., an operating company that ships products embodying the claims, is the current assignee. The other entities in the chain, CIT Northbridge Credit LLC and BOKF, NA D/B/A BOK FINANCIAL, are financial institutions involved in security agreements, not direct ownership transfers for assertion purposes (Reel 062003/0523, Reel 065630/0906, Reel 072338/0695). The litigation associated with this patent (IPR proceedings and district court cases) suggests assertion by the operating company or a licensee thereof.

Verification: https://assignmentcenter.uspto.gov/

US Patent 10788690, titled "Optical isolator array for use in an optical subassembly module," was granted on September 29, 2020, from an application filed on January 25, 2019. It is currently active and is expected to expire on May 10, 2039.

The patent describes an optical isolator array featuring a magnetic base for mounting and aligning multiple optical isolators within an optical subassembly module. The magnetic base provides a mounting surface for N optical isolators, where N corresponds to the optical channel count (e.g., 4-channels, 8-channels). These optical isolators can be arranged along the same axis and at a uniform distance from each other. An adhesive, such as UV-curing optical adhesive, is used to secure the optical isolators in place and enhance structural integrity. In an alternative embodiment, the array can include first and second magnetic bases with the optical isolators sandwiched between them. This configuration can offer greater isolation performance due to the presence of two magnetic fields. The modular design allows for easy modification of the number of optical isolators and the pitch between them to suit different housing requirements and channel counts without significant redesign.

The USPTO provides tools like "Patent Public Search" to search its database for patents and patent application publications. To search for a specific patent number, leading zeros may be required if the number has fewer than 7 digits. For example, a 6-digit patent number should be entered with a leading zero to make it 7 digits (e.g., 123456 becomes 0123456).

Here is an analysis of the most relevant prior art cited in US Patent 10788690:

Patent Citations:

1. US20100002988A1:

   • Full Citation: US20100002988A1, "Optical Isolator"
   • Publication/Filing Date: Published: January 7, 2010; Priority Date: July 1, 2008.
   • Brief Description: This patent application describes an optical isolator. Although the full details of this specific reference aren't provided in the given text, typically optical isolators prevent unwanted reflections in optical systems.
   • Potential Anticipated Claim(s): This reference would likely be relevant to claims generally describing an optical isolator and its function, such as aspects of claims 1, 4, and 11, particularly regarding the concept of an optical isolator itself and its role in an optical system. Without more specific details on the optical isolator described in US20100002988A1, it's difficult to pinpoint exact claim elements it anticipates beyond the broad concept of an optical isolator.

2. US20140146389A1:

   • Full Citation: US20140146389A1, "Optical Isolator Capable of Creating a Large Buffer Area for Optical Beams and Methods of Manufacturing and Using the Same"
   • Publication/Filing Date: Published: May 29, 2014; Priority Date: November 28, 2012.
   • Brief Description: This patent application describes an optical isolator designed to create a large buffer area for optical beams, along with its manufacturing methods.
   • Potential Anticipated Claim(s): This reference might anticipate claims related to the design and manufacturing of optical isolators, especially if the large buffer area or manufacturing methods described therein touch upon the mounting or positioning aspects of the optical isolators. This could be relevant to aspects of claims 1 and 11, particularly concerning the structure and arrangement of optical isolators within an assembly.

Without further details on the specific content of each cited patent and a more in-depth comparison of their disclosures to each element of the claims in US10788690, a definitive determination of anticipation under 35 U.S.C. § 102 cannot be made. The analysis above is based on the limited descriptions available in the provided text.

Obviousness Analysis of US10788690 under 35 U.S.C. § 103

To determine the obviousness of US10788690, we apply the framework established in Graham v. John Deere Co. and reiterated in KSR International Co. v. Teleflex Inc.. This involves:

1. Determining the scope and content of the prior art.
2. Ascertaining the differences between the claimed invention and the prior art.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering secondary considerations of non-obviousness.

A patent claim may be considered obvious if the differences between the invention and the prior art would have been obvious at the time of filing to a person having ordinary skill in the art (PHOSITA). The motivation to combine references can arise from various sources, including design incentives, market forces, or the recognition that a technique used to improve one device would similarly improve another device in the same way. An explicit reason to modify prior art in the references themselves is not always required.

The pertinent art for US10788690 is optical communications, particularly optical isolator arrays for multi-channel optical subassembly modules, including TOSA and ROSA arrangements. A PHOSITA in this field would likely have an undergraduate degree in electrical engineering or a related field and experience with optical transceiver design and manufacturing.

Independent Claim 1 Analysis:

Claim 1: An optical isolator array for use in an optical subassembly module, the optical isolator array comprising: a first magnetic base defining at least one mounting surface; a plurality of optical isolators mounted to the at least one mounting surface, each of the plurality of optical isolators disposed substantially in parallel relative to each other; and at least one layer of adhesive disposed on the at least one mounting surface to couple the plurality of optical isolators to the first magnetic base and to hold each optical isolator of the plurality of optical isolators at a predefined position relative to each other.

Prior Art References:

• US2010/0002988A1 (Duke University): Discloses an optical isolator.
• US2014/0146389A1 (Ye): Discloses an optical isolator.
• JPH0730207A (Mitsubishi Electric Corp.): Discloses a semiconductor laser array module and its assembling method.
• JPH10123462A (Hoya Corp.): Concerns the manufacture of optical isolators, polarizing elements, and Faraday elements.
• JP2001242419A (Oyokoden Lab Co Ltd): Describes a method for manufacturing an optical isolator.
• WO2003093896A1 (Corning Inc.): Discloses optical isolators and methods of manufacturing using direct bonding, including sandwiching a Faraday rotator between polarizers. It also mentions that a Faraday rotator can utilize a permanently magnetized or latching garnet that does not require an external magnetic field.
• US9866329B2 (Applied Optoelectronics, Inc.): Discloses an optical transmitter or transceiver including TOSA modules directly aligned to optical multiplexer inputs. It describes a multi-channel optical transmitter or transceiver with TOSA modules that are optically coupled and directly aligned with mux input ports of an optical multiplexer, without using optical fibers. The TOSA modules may include a base supporting a laser, laser driving circuitry, and a lens.
• CN204947313U (Ningbo Global Radio & Television Technology Co., Ltd.): Discloses a multichannel array fiber laser.
• PGA Series (Excelitas Technologies): Describes a series of pulsed semiconductor lasers available in single, double, triple, or quadruple epi-cavity versions, which can be stacked to further increase output power. These devices are hermetically packaged and grown on a single GaAs substrate chip.

Differences and Obviousness:

1. "A first magnetic base defining at least one mounting surface":

   • WO2003093896A1 discusses Faraday rotators and mentions that some utilize a permanently magnetized or latching garnet that does not require an external magnetic field. This implies the use of a magnetic element within the isolator structure.
   • The concept of a "base" for mounting components is generic in optical modules, as seen in US9866329B2 which describes TOSA modules having a base supporting a laser and other components.
   • A PHOSITA, aware of magnetic materials for optical isolators, would find it obvious to integrate the magnetic material into a "first magnetic base" to serve as a mounting surface for the optical isolators, thereby simplifying the overall structure and providing the necessary magnetic field. The use of a magnetic base to provide a magnetic field and simultaneously serve as a mounting platform for optical components is a logical combination for space-constrained optical subassemblies.

2. "A plurality of optical isolators mounted to the at least one mounting surface, each of the plurality of optical isolators disposed substantially in parallel relative to each other":

   • Multi-channel optical systems are well-known in the prior art. For example, US9866329B2 discloses multi-channel optical transmitters with multiple TOSA modules, and CN204947313U discloses a multichannel array fiber laser.
   • The PGA Series describes multi-epi semiconductor lasers with up to four active lasing cavities on a single substrate, and the possibility of stacking to increase output power, implying a parallel arrangement of light paths.
   • JPH0730207A describes a semiconductor laser array module, further indicating the commonality of arrays of optical components.
   • It would be obvious to a PHOSITA to arrange multiple optical isolators in parallel to correspond with multiple optical channels in a multi-channel optical subassembly, given the prevalence of multi-channel systems. The "substantially in parallel" arrangement is a natural consequence of aligning multiple optical paths.

3. "At least one layer of adhesive disposed on the at least one mounting surface to couple the plurality of optical isolators to the first magnetic base and to hold each optical isolator of the plurality of optical isolators at a predefined position relative to each other":

   • The use of adhesives for securing optical components is a common practice in the field. JP2001242419A describes methods for manufacturing optical isolators, which often involve securing components.
   • US10788690 itself mentions that UV-curing optical adhesives can be used to secure optical isolators and provide structural support, and that "other types of adhesives and fixation approaches may be utilized". This suggests that the use of adhesive itself is a known technique.
   • Methods for forming optical devices often involve adhering components to substrates.
   • A PHOSITA would find it obvious to use an adhesive to mount and secure optical isolators to a magnetic base, providing both mechanical coupling and precise positioning, particularly for fine-grain adjustments as described in the patent (e.g., less than 10 microns). The use of adhesive for positioning is a standard manufacturing technique for optical components.

Combination of References and Motivation:

A combination of WO2003093896A1, US9866329B2, and JPH0730207A with general knowledge of adhesive bonding would render Claim 1 obvious.

• Motivation to use a magnetic element as a base (WO2003093896A1 + US9866329B2): WO2003093896A1 teaches optical isolators that can use permanently magnetized material. US9866329B2 teaches a TOSA module with a base supporting optical components. A PHOSITA would be motivated to combine the magnetic properties of an isolator (from WO2003093896A1) with the structural function of a base (from US9866329B2) to create a single magnetic base that both provides the necessary magnetic field for the isolators and acts as a mounting platform, thereby reducing component count and simplifying assembly in a compact optical subassembly. This would be a predictable variation to integrate functionality, especially given the "desire to provide higher transmit/receive speeds in increasingly space-constrained optical transceiver modules".

• Motivation for a plurality of parallel isolators (US9866329B2 + JPH0730207A): US9866329B2 highlights multi-channel optical transmitters, implying the need for multiple optical components for different channels. JPH0730207A shows a semiconductor laser array module, demonstrating the existing concept of arrays of active optical components. A PHOSITA would naturally apply the array concept to optical isolators (known from US2010/0002988A1 or US2014/0146389A1) to serve multiple channels in parallel, matching the array of laser diodes in a TOSA, as taught by US9866329B2. The parallel disposition is inherent to multi-channel optical alignment.

• Motivation to use adhesive for mounting and positioning: The use of adhesive for mounting and precisely positioning small optical components is a widely known and utilized technique in optical manufacturing, recognized for enabling fine-grain adjustments. This common knowledge, combined with the need to securely attach optical isolators to a base in an array configuration, would make the use of adhesive obvious.

Therefore, the combination of these prior art references and general knowledge in the field would lead a PHOSITA to the claimed optical isolator array.

Independent Claim 11 Analysis:

Claim 11: An optical transceiver, the optical transceiver comprising: a transceiver housing; at least one optical transmitter subassembly (TOSA) arrangement disposed in the transceiver housing, the at least one TOSA arrangement comprising: a substrate defined by at least one mounting surface; a plurality of laser diodes mounted to the at least one mounting surface of the substrate, each laser diode of the plurality of laser diodes to emit a different associated channel wavelength along a corresponding light path of a plurality of light paths; and an optical isolator array mounted to the at least one mounting surface adjacent the plurality of laser diodes such that the plurality of light paths intersect with the optical isolator array, the optical isolator array comprising a at least a first magnetic base and a plurality of optical isolators coupled thereto, and wherein each optical isolator is optically aligned with a corresponding laser diode of the plurality of laser diodes via a corresponding light path; an optical receiver subassembly (ROSA) disposed in the transceiver housing.

Prior Art References:

• US9866329B2 (Applied Optoelectronics, Inc.): Discloses a multi-channel optical transmitter or transceiver including TOSA modules directly aligned to optical multiplexer inputs. It explicitly mentions a transceiver housing, TOSA arrangement with a base supporting lasers, and an optical multiplexer for combining channel wavelengths. It also describes a multi-channel ROSA for receiving and demultiplexing optical signals.
• JPH0730207A (Mitsubishi Electric Corp.): Discloses a semiconductor laser array module and its assembling method.
• US2010/0002988A1 (Duke University): Discloses an optical isolator.
• US2014/0146389A1 (Ye): Discloses an optical isolator.
• WO2003093896A1 (Corning Inc.): Discloses optical isolators, including those with permanently magnetized materials.
• PGA Series (Excelitas Technologies): Describes multi-epi pulsed semiconductor lasers with multiple active lasing cavities on a single substrate.
• Link-PP article on TOSA: Defines a TOSA as a key component of an optical transceiver that converts electrical signals to optical signals for transmission over fiber-optic networks. It typically includes a laser source, monitor photodiode, and optical coupling elements packaged in a compact, thermally stable module.
• HUBER+SUHNER Cube Optics: Describes multi-lambda TOSAs designed for high-speed transceivers, receiving multiple electrical channels and converting them via integrated laser diodes to multiple optical signals, which are then multiplexed. It also mentions ROSAs.

Differences and Obviousness:

Claim 11 combines elements well-known in optical transceivers with the optical isolator array features of Claim 1.

1. "A transceiver housing; at least one optical transmitter subassembly (TOSA) arrangement disposed in the transceiver housing...":

   • US9866329B2 explicitly describes a multi-channel optical transmitter or transceiver with a housing, and TOSA modules mounted to the housing. The Link-PP article and HUBER+SUHNER Cube Optics also describe TOSAs as key components within optical transceivers. This element is clearly taught by prior art.

2. "...the at least one TOSA arrangement comprising: a substrate defined by at least one mounting surface; a plurality of laser diodes mounted to the at least one mounting surface of the substrate, each laser diode of the plurality of laser diodes to emit a different associated channel wavelength along a corresponding light path of a plurality of light paths":

   • US9866329B2 mentions TOSA modules with a base supporting at least a laser, and the multi-channel nature implies a plurality of lasers emitting different channel wavelengths.
   • JPH0730207A teaches a semiconductor laser array module, further supporting the concept of multiple laser diodes on a substrate.
   • The PGA Series describes multi-epi semiconductor lasers with up to four active lasing cavities on a single substrate, emphasizing multiple light sources.
   • This arrangement of multiple laser diodes on a substrate emitting different channel wavelengths is a standard feature of multi-channel optical transmitters.

3. "An optical isolator array mounted to the at least one mounting surface adjacent the plurality of laser diodes such that the plurality of light paths intersect with the optical isolator array, the optical isolator array comprising a at least a first magnetic base and a plurality of optical isolators coupled thereto, and wherein each optical isolator is optically aligned with a corresponding laser diode of the plurality of laser diodes via a corresponding light path":

   • As established in the analysis of Claim 1, the optical isolator array with a first magnetic base and plurality of isolators is a combination of known elements.
   • The placement of optical isolators in the light path of laser diodes within a TOSA to prevent back reflections and maintain laser stability is a well-known function in optical systems. US2010/0002988A1 and US2014/0146389A1 disclose optical isolators generally. Many laser applications are prone to specular reflections back into the source, causing overheating and decreased stability and lifetime, and optical isolators are used to eliminate such back reflections.
   • US9866329B2 teaches that TOSA modules are "directly aligned with mux input ports of an optical multiplexer." This implies precise alignment of components within the TOSA.
   • A PHOSITA would understand the necessity of integrating optical isolators into the light path of laser diodes in an optical transceiver to maintain signal integrity and laser performance. The arrangement of such an array "adjacent the plurality of laser diodes" with corresponding optical alignment is a direct application of known principles in optical design.

4. "An optical receiver subassembly (ROSA) disposed in the transceiver housing":

   • US9866329B2 explicitly describes a multi-channel optical transceiver as including a multi-channel ROSA. The HUBER+SUHNER Cube Optics also discusses ROSAs as components in high-speed transceivers. This is a conventional element of a full optical transceiver.

Combination of References and Motivation:

A combination of US9866329B2, JPH0730207A, WO2003093896A1, and general knowledge regarding optical isolator function would render Claim 11 obvious.

• Motivation to integrate an optical isolator array into a TOSA (US9866329B2 + WO2003093896A1 + JPH0730207A): US9866329B2 describes multi-channel TOSAs with laser diodes and emphasizes direct alignment with multiplexer inputs. Optical isolators (as taught by WO2003093896A1 or the Duke/Ye patents) are known components for protecting lasers from back reflections and ensuring stable operation. Given that JPH0730207A teaches laser arrays, and US9866329B2 teaches multi-channel TOSAs, a PHOSITA would be motivated to integrate an array of optical isolators into the TOSA module, positioned after the laser diodes, to protect all channels simultaneously. This is a predictable application of a known component (optical isolator) to a known system (multi-channel TOSA with laser array) to achieve its intended and known function (preventing back reflection and improving laser stability). The "first magnetic base" for the isolator array, as discussed for Claim 1, would further simplify this integration. The optical alignment of each isolator with its corresponding laser diode is an inherent requirement for any optical system.

• Motivation for the complete transceiver structure (US9866329B2): US9866329B2 explicitly describes an optical transceiver including both a TOSA and a ROSA within a transceiver housing. This patent serves as a strong primary reference for the overall structure of Claim 11.

Therefore, the combination of these prior art references would lead a PHOSITA to the claimed optical transceiver.