PTAB

IPR2014-01382

Fujitsu Network Communications Inc v. Thomas Swan & Co Ltd

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Petition
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1. Case Identification

2. Patent Overview

  • Title: Optical Device
  • Brief Description: The ’683 patent relates to an optical device using a reflective Liquid Crystal on Silicon (LCOS) Spatial Light Modulator (SLM) with an array of phase-modulating elements. The device is designed to receive a multiplexed beam of optical signals at different wavelengths, separate the signals into groups, and process at least one group adaptively.

3. Grounds for Unpatentability

Ground 1: Anticipation - Claim 18 is anticipated by Parker Thesis under 35 U.S.C. §102.

  • Prior Art Relied Upon: Parker Thesis (a November 1996 Ph.D. dissertation titled "Dynamic Holograms for Wavelength Division Multiplexing").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Parker Thesis discloses every limitation of independent claim 18. Parker describes a space-wavelength switch that uses a pixelated Ferroelectric Liquid Crystal (FLC) SLM coupled with a mirror, constituting a reflective LCOS SLM. The device receives a multiplex of optical signals in a common beam, uses a transmissive grating to separate the signals into wavelength groups, and processes at least one group using the SLM. Petitioner asserted that Parker’s described "folded 2f architecture" employing a reflective SLM on a silicon backplane directly reads on the claim's requirement for a "reflective LCOS SLM."

Ground 2: Obviousness over Core Cambridge Research - Claims 18, 20, 22, 24, and 25 are obvious over Parker Thesis in view of Warr Thesis under 35 U.S.C. §103.

  • Prior Art Relied Upon: Parker Thesis (a 1996 Ph.D. dissertation) and Warr Thesis (a July 1996 Ph.D. dissertation titled "Free Space Switching for Optical Fibre Networks").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Parker provides the foundational optical device as outlined in Ground 1. Warr Thesis was argued to supply the teachings for the dependent claims, specifically disclosing that an SLM can be divided into distinct "sub-hologram routeing areas" to process different input signals. Warr teaches using CMOS VLSI technology for control circuitry to address individual pixels or blocks of pixels, and to display distinct, independently controlled holograms on these blocks to achieve an arbitrary routing pattern. This combination was alleged to render the limitations of dividing the SLM into blocks of pixels and using control circuitry to manage them obvious.
    • Motivation to Combine: A POSITA would combine Parker and Warr because both theses originated from the same research group at Cambridge University, addressed nearly identical problems in optical routing, cited each other’s work, and in some cases used the same equipment. Petitioner argued a POSITA would be motivated to incorporate Warr's more advanced sub-hologram routing technique into Parker's space-wavelength switch to improve functionality and routing efficiency for multiple wavelengths.
    • Expectation of Success: Success would be expected, as the combination involved applying a known technique (sub-hologram routing from Warr) to a similar, compatible system (the optical switch in Parker) to achieve the predictable result of more granular signal processing.

Ground 3: Obviousness with Power Control - Claims 29, 30, 31, and 34 are obvious over Parker Thesis, Warr Thesis, and Crossland under §103.

  • Prior Art Relied Upon: Parker Thesis, Warr Thesis, and Crossland (a December 2000 journal article titled "Holographic Optical Switching: The ‘ROSES’ Demonstrator").

  • Core Argument for this Ground:

    • Prior Art Mapping: Building on the combination of Parker and Warr, Petitioner asserted that Crossland teaches the specific limitations related to power control. The Crossland article, which lists the ’683 patent’s inventor as a co-author, describes a switch demonstrator using a reflective FLC/Si SLM where the hologram acts as a phase-only diffraction grating. By controlling the "phase modulation pattern (the hologram)," the system can control the deflection angle and, critically, the power coupled into the output waveguide. This, Petitioner argued, directly teaches the claimed concept of displaying a "power control hologram" to selectively control the attenuation of an incident light beam.
    • Motivation to Combine: A POSITA would combine Crossland with the Parker/Warr system because all references are in the same technical field of holographic optical switching and originate from the same research community. Adding a known method for signal attenuation (from Crossland) to a routing switch (from Parker/Warr) would be a logical and well-understood step to create a more complete and functional optical processing system.
    • Expectation of Success: The combination would predictably result in a switch with integrated power control, as adding attenuation functionality is a standard design choice in optical systems.

  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of Parker and Warr with Rancuret (Patent 6,958,841), Crossland Patent (Application # 2001/0050787), Tomlinson (Patent 6,549,865), and Cohen (a 1999 journal article) to teach limitations related to pixel block reconfiguration, guardbands, and adjacent channel filtering, respectively.

4. Key Claim Construction Positions

  • "phase-modulating elements": Petitioner proposed this term means "components, such as pixels, which can change the phase of incident light under certain conditions, such as application of voltage." This construction was argued to be consistent with the specification and necessary to understand the function of the claimed array.
  • "hologram": The petition contended the term is potentially indefinite but, if not, should be construed as "a set of modulation values for achieving the desired change in incident light." This construction was presented as crucial for interpreting how the prior art’s phase patterns meet the claim limitations.
  • "SLM" / "spatial light modulator": Petitioner proposed a construction of "a device that modifies a property of light as a function of time and position across the device, and is at least somewhat polarisation-independent," arguing the specification disclaims devices that are not polarization insensitive.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 18, 20, 22, 24-31, 34, 38, 39, and 42-44 of the ’683 patent as unpatentable.