PTAB

IPR2015-01958

Ciena Corp v. Capella Photonics Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Wavelength Selective Switch and Method Therefor
  • Brief Description: The ’368 patent describes an optical add-drop apparatus, specifically a reconfigurable optical add-drop multiplexer (ROADM), for use in wavelength-division multiplexing (WDM) fiber-optic communication systems. The technology uses a spatial array of beam-deflecting elements, such as Micro-Electro-Mechanical Systems (MEMS) mirrors, to selectively switch, route, and control the power of individual wavelength channels. The patent is a reissue of Patent 6,879,750, and key amendments made during reissue added limitations requiring the beam-deflecting elements to be controllable in two dimensions to control the power of the optical channels.

3. Grounds for Unpatentability

Ground 1: Obviousness over Bouevitch and Carr - Claims 1, 2, 5, 6, 9-12, and 15-21 are obvious over Bouevitch in view of Carr.

  • Prior Art Relied Upon: Bouevitch (Patent 6,498,872) and Carr (Patent 6,442,307).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Bouevitch discloses a configurable optical add-drop multiplexer (COADM) that uses an array of MEMS mirrors to switch spectral channels between ports. However, Bouevitch’s mirrors operate with only one axis of rotation. Carr was argued to cure this deficiency by disclosing a MEMS mirror device featuring a two-dimensional array of double-gimbaled mirrors that can be tilted about two perpendicular axes to any desired orientation. Critically, Carr also teaches using this two-axis control for power attenuation by intentionally misaligning the mirrors so only a portion of the reflected signal enters an output fiber. The combination of Bouevitch’s COADM architecture with Carr’s two-axis, power-controlling mirrors allegedly renders the key limitations of the independent claims obvious.
    • Motivation to Combine: A POSITA would combine Bouevitch and Carr because both references address optical switching in WDM systems using MEMS-based wavelength selective switches. Petitioner asserted that implementing Carr's known two-axis mirrors in Bouevitch's system would be a predictable and obvious improvement. This modification would provide better control over beam positioning to compensate for system alignment errors—a known problem in the field. The combination was presented as a simple substitution of a known element (two-axis mirrors for one-axis mirrors) from a finite number of predictable solutions to improve a known device.
    • Expectation of Success: A POSITA would have a high expectation of success, as two-axis mirrors were a well-known and available technology at the time, and the effect of tilting mirrors to steer a light beam was entirely predictable.

Ground 2: Obviousness over Bouevitch and Sparks - Claims 1-4, 17, and 22 are obvious over Bouevitch in view of Sparks.

  • Prior Art Relied Upon: Bouevitch (Patent 6,498,872) and Sparks (Patent 6,625,340).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presents a similar combination to Ground 1. Bouevitch discloses the base COADM system with one-axis mirrors. Sparks, like Carr, discloses an optical switch using movable micromirrors with two-axis movement for attenuating signals via deliberate misalignment. Thus, the combination of Bouevitch and Sparks was argued to teach the core limitations of two-dimensional power control. Further, Petitioner contended that Sparks explicitly discloses a closed-loop servo control system to monitor optical power and control the mirror misalignment to achieve a predetermined output power. This teaching was argued to render the "servo-control assembly" limitations of claims 3 and 4 obvious.
    • Motivation to Combine: Petitioner incorporated the motivations from Ground 1, arguing that combining Sparks’ two-axis mirror system with Bouevitch’s COADM would be an obvious substitution to yield predictable results. Additionally, a POSITA would be motivated to integrate Sparks' internal closed-loop servo control system into Bouevitch's device. This would provide a known method to ensure that the desired degree of attenuation is achieved for each channel, thereby improving the performance and stability of the system without requiring external feedback mechanisms.
    • Expectation of Success: A POSITA would have a high expectation of success for the same reasons as in Ground 1, as the combination involves implementing known components (two-axis mirrors and servo control) to achieve their predictable functions in a similar system.

4. Key Claim Construction Positions

  • "in two dimensions": Petitioner argued for a construction of "in two axes." This construction was based on the ’368 patent specification, which consistently describes the beam-deflecting elements as mirrors that pivot or tilt along two axes ("biaxially") to switch beams between ports and to control power.
  • "continuously controllable": Petitioner proposed the construction "under analog control." The petition asserted that the specification explicitly contrasts the invention with prior art by stating that a "distinct feature" is the "analog control such that its pivoting angle can be continuously adjusted."
  • "beam-deflecting elements": Petitioner argued for the construction "moveable mirrors." This was supported by specification language describing the elements as "silicon micromachined mirrors, reflective ribbons (or membranes), or other types of beam-deflecting elements known in the art," which are pivoted or rotated.
  • "servo-control assembly" (Claims 3 & 4): Petitioner proposed construing this term as an "assembly that uses automatic feedback to control a device in response to a control signal." This was based on the specification’s description of the assembly using a spectral monitor to provide "feedback control" of the micromirrors to maintain a predetermined power level.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6, 9-12, and 15-22 of the ’368 patent as unpatentable.