PTAB

IPR2026-00122

Eoptolink Technology USA Inc v. Applied Optoelectronics Inc

Log In
Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Transmitter Optical Subassembly with Vertically-Mounted Monitor Photodiodes
  • Brief Description: The ’890 patent discloses a transmitter optical sub-assembly (TOSA) module designed to reduce housing dimensions and improve radio frequency (RF) signal quality. The purported novelty centers on using a feedthrough device to provide a vertical mounting surface for monitor photodiodes (MPDs), which are positioned transverse to the laser diode (LD) mounting surface to receive back-side emissions.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claim 1 - Claim 1 is anticipated by Takashi under 35 U.S.C. §102.

  • Prior Art Relied Upon: Takashi (Japanese Patent Publication No. JP 2010-161146).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Takashi discloses every limitation of claim 1. Takashi’s optical transmission module includes a circuit board (17) that serves as the claimed "base portion." This base portion includes ceramic blocks (17a, 17b) with electrode pads and conductors, forming a "feedthrough device." This feedthrough device provides a vertical PD carrier (19) for mounting a monitor photodiode (18), which constitutes the claimed "vertical MPD mounting surface." Takashi’s monitor photodiode is positioned to receive rearward-emitted light from the laser diode (14), and the vertical mounting surface (19) extends substantially transverse to the LD mounting surface (21a), meeting all claim limitations.

Ground 2: Obviousness over Takashi and Sato - Claims 2-9 are obvious over Takashi in view of Sato.

  • Prior Art Relied Upon: Takashi (Japanese Patent Publication No. JP 2010-161146) and Sato (Patent 9,385,830).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Takashi provides the base TOSA structure as detailed in Ground 1. Sato, which describes a multi-channel transmitter module, supplies the remaining limitations of the dependent claims. Sato explicitly teaches key features such as a hermetically sealed housing (for claim 3), a thermoelectric cooler (TEC) mounted on a sidewall (for claim 4), the use of multiple laser diodes emitting at different wavelengths (for claim 7), and an optical multiplexer, which may be an arrayed waveguide grating (AWG), to combine the signals (for claims 8-9).
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Takashi’s compact and efficient TOSA design with Sato’s multi-channel capabilities to develop a modern Wavelength Division Multiplexing (WDM) transmitter. The motivation would be to achieve the well-known benefits of WDM systems, such as increased bandwidth and network capacity, by adapting Takashi’s single-channel design for multi-channel applications using the conventional components taught by Sato.
    • Expectation of Success: A POSITA would have reasonably expected success because both references operate in the same field of optical transmitters and use standard, well-understood components. The combination represents a predictable integration of known elements (a multi-channel architecture from Sato) with an improved component (the compact TOSA from Takashi) to achieve a known goal.

Ground 3: Obviousness over Ho, Takashi, and Sato - Claims 15-19 are obvious over Ho in view of Takashi and further in view of Sato.

  • Prior Art Relied Upon: Ho (Patent 9,306,671), Takashi (Japanese Patent Publication No. JP 2010-161146), and Sato (Patent 9,385,830).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addresses the broader "multi-channel optical transceiver module" claims. Petitioner argued that Ho provides the primary framework, disclosing a multi-channel optical transceiver that includes a multi-channel TOSA coupled to a printed circuit board assembly (PCBA). A POSITA would find it obvious to replace Ho’s generic TOSA with the improved, space-saving TOSA taught by Takashi to enhance optical coupling efficiency and reduce the length of electrical interconnects. To implement the multi-channel aspect required by Ho and the claims, the POSITA would incorporate the teachings of Sato, which explicitly discloses using multiple LDs and corresponding MPDs in a WDM transmitter.
    • Motivation to Combine: A POSITA developing a multi-channel transceiver like Ho’s would be motivated to use a more efficient and compact TOSA design, such as that disclosed in Takashi. To make this improved TOSA suitable for a multi-channel WDM system as described by Ho, the POSITA would naturally turn to established techniques for implementing multiple lasers and detectors, as taught by Sato. The combination aims to leverage the benefits of each reference: Ho’s system, Takashi’s efficiency, and Sato’s multi-channel functionality.
    • Expectation of Success: The proposed combination would have been a routine design choice with a high expectation of success. It involves integrating an improved sub-component (Takashi's TOSA) into a known system (Ho's transceiver) and adapting it for multi-channel operation using well-understood methods (from Sato), yielding predictable results.

4. Arguments Regarding Discretionary Denial

  • Petitioner provided a Sotera-Plus stipulation to weigh against discretionary denial under Fintiv. Petitioner stipulated that if the inter partes review (IPR) is instituted, it will not pursue in the parallel district court litigation the specific grounds raised in the petition or any other grounds that reasonably could have been raised based on patents or printed publications.

5. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-9 and 15-19 of Patent 10,714,890 as unpatentable.