PTAB

IPR2025-00435

Cambridge Industries USA Inc. v. Applied Optoelectronics, Inc.

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1. Case Identification

2. Patent Overview

  • Title: Optical Transceiver Module
  • Brief Description: The ’116 patent relates to an optical transceiver module containing an arrayed waveguide grating (AWG) chip. The technology focuses on using a tapered, angled region at one end of the AWG to reflect demultiplexed light towards an output interface on the same side as the substrate, intended to improve optical coupling and component layout.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-11 - Claims 1-11 are unpatentable under 35 U.S.C. §102 as anticipated by Soldano.

  • Prior Art Relied Upon: Soldano (Patent 9,768,901).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Soldano teaches every element of independent claim 1. Specifically, Soldano disclosed a photonics module with an AWG demultiplexer on a silicon photonics chip (the "substrate"). Petitioner asserted that Soldano’s polished angled end face (409) is a "tapered region" that receives light from output waveguides and reflects it towards photodetectors (the "exposed output interface region") located on the same side as the substrate, without the light passing through the substrate.
    • Key Aspects: Petitioner noted that Soldano was cited in an Information Disclosure Statement (IDS) during prosecution of the ’116 patent but was not applied in any rejection by the Examiner.

Ground 2: Anticipation of Claims 1-11 - Claims 1-11 are unpatentable under §102 as anticipated by Shen.

  • Prior Art Relied Upon: Shen (Application # 2016/0349451) and its corresponding provisional application.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Shen disclosed an optical receiver module with an AWG chip (200) mounted on a substrate (100). Shen’s angled end (400) was identified as the claimed "tapered region" that redirects light from waveguides (278) to a photodetector array (300). Petitioner argued this structure inherently meets the limitation that the output interface region emits light on the same side as the substrate without passing through it.
    • Key Aspects: Shen was also cited in an IDS during prosecution but was not used in a rejection. Petitioner asserted that Shen’s disclosure of a reflector angle between 40° and 50° anticipates the range recited in dependent claim 4 (41° to 45°).

Ground 3: Obviousness of Claims 1-11 - Claims 1-11 are obvious over Kanazawa in view of Sasaki.

  • Prior Art Relied Upon: Kanazawa (JP 2012-034314A), Sasaki (JP 2003-215371A).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Kanazawa disclosed a multi-channel optical receiver with a PLC including a demultiplexer and 45-degree mirrors (15) to redirect light to photodetectors. Sasaki disclosed a PLC with an angled end (4) for orthogonally redirecting light between horizontal waveguides and vertical photodetectors. Petitioner contended it would have been obvious to replace Kanazawa's embedded mirrors with Sasaki's simpler, integrated angled end structure.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Kanazawa and Sasaki to increase signal density, improve compactness, and simplify the manufacturing and assembly of the photonics module. Both references address the same technical problems in the same field.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in this combination because it involved substituting one known light-redirecting optical structure (mirrors) for another (an angled end face) to achieve a predictable improvement in manufacturability.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 12-19 are obvious over Soldano in view of Lurie (Patent 5,351,327) or Tomita (Patent 4,978,193); claims 12-19 are obvious over Shen in view of Soldano, Lurie, or Tomita; and claims 12-19 are obvious over Kanazawa and Sasaki in further view of Lurie or Tomita. These grounds primarily relied on Lurie and Tomita to teach the use of angled physical contact for input coupling to reduce back-reflections, a well-known technique.

4. Key Claim Construction Positions

  • "substrate" and "disposed on the substrate": Petitioner argued that, based on the ’116 patent’s specification and prosecution history, "substrate" should be construed narrowly as "a silicon or silicon-based layer on which the cladding and core layers are deposited to form the PLC." This construction is critical because the patentee allegedly added the limitation that light is emitted "without passing the received light through the substrate" to overcome prior art. Petitioner contrasted this with the Patent Owner’s broader construction in co-pending litigation ("a supporting structure for an AWG device"), which Petitioner argued is improper and would render the distinguishing limitation meaningless.

5. Arguments Regarding Discretionary Denial

  • §325(d) (Same or Similar Art): Petitioner argued against discretionary denial under §325(d), asserting that the primary references in its main grounds (Soldano, Shen, Kanazawa, Sasaki) were either not applied or not cited at all during prosecution. Therefore, the petition raised art and arguments with material differences from those previously before the Examiner.
  • §314(a) (Fintiv Factors): Petitioner contended that discretionary denial under Fintiv is inappropriate. The parallel district court case is in a very early stage, with claim construction not scheduled until April 2025 and trial not until June 2026. Petitioner argued the court will not have invested significant resources before the Board’s institution decision, and Petitioner stipulated that, if instituted, it would not pursue the same invalidity grounds in district court, thus streamlining the parallel proceeding.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-19 of the ’116 patent as unpatentable.