PTAB

IPR2014-01166

Cisco Systems Inc v. Capella Photonics Inc

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petition

1. Case Identification

2. Patent Overview

  • Title: Reconfigurable Optical Add-Drop Multiplexers with Servo Control and Dynamic Spectral Power Management Capabilities
  • Brief Description: The ’368 patent describes a reconfigurable optical add-drop multiplexer (ROADM) for use in wavelength division multiplexing (WDM) fiber-optic networks. The apparatus uses a spatial array of beam-deflecting elements, such as micro-electromechanical systems (MEMS) mirrors, to selectively route individual wavelength channels to different output ports (e.g., pass-through, drop, or add ports) and to control the power of those channels.

3. Grounds for Unpatentability

Ground 1: Obviousness over Bouevitch and Smith - Claims 1-6, 9-13, and 15-22 are obvious over Bouevitch in view of Smith.

  • Prior Art Relied Upon: Bouevitch (Patent 6,498,872) and Smith (Patent 6,798,941).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Bouevitch, a reference the Patent Owner acknowledged during reissue, discloses every element of the independent claims except for the use of beam-deflecting elements controllable in two dimensions for power control. Bouevitch teaches a ROADM that uses single-axis MEMS mirrors for both channel switching and power attenuation. Smith was alleged to cure this deficiency by disclosing a very similar MEMS-based ROADM that explicitly uses two-axis tiltable mirrors, with one axis designated for channel switching and the orthogonal axis used for variable power transmission. The combination of Bouevitch’s foundational ROADM architecture with Smith’s two-axis mirror control system was asserted to render the claims obvious. For dependent claims, Smith’s disclosure of a feedback-based control system using a microprocessor and an optical power monitor was argued to teach the "servo-control assembly" and "spectral monitor" limitations of claims 3 and 4.
    • Motivation to Combine: A POSITA would combine these references for several reasons. First, it represented a simple substitution of one known element (Bouevitch's 1-axis mirrors) for a known, improved alternative (Smith's 2-axis mirrors) to achieve predictable results. Smith itself stated that 1-axis and 2-axis mirrors are interchangeable. Second, a POSITA would be motivated to use Smith’s 2-axis mirrors to improve Bouevitch’s design by reducing crosstalk (by separating the switching and power control axes) and increasing port density, which is enabled by two-dimensional beam steering.
    • Expectation of Success: A POSITA would have a high expectation of success because both references operate in the same field (WDM optical switching), address the same problems, and use compatible MEMS-based technology. The effect of tilting a mirror in one or two axes to steer a light beam was entirely predictable.

Ground 2: Obviousness over Bouevitch, Smith, and Lin - Claims 1-6, 9-13, and 15-22 are obvious over Bouevitch in view of Smith and further in view of Lin.

  • Prior Art Relied Upon: Bouevitch (Patent 6,498,872), Smith (Patent 6,798,941), and Lin (Patent 5,661,591).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground was presented as an alternative to Ground 1, specifically to bolster the teaching of the "continuously controllable" limitation. Petitioner asserted that while Bouevitch and Smith sufficiently teach this element, Lin provides an explicit disclosure of continuous, analog control of MEMS mirrors. Lin describes the benefits of analog control over discrete control for achieving higher precision in mirror placement and includes a graph showing a continuous, linear relationship between applied voltage and mirror deflection angle.
    • Motivation to Combine: A POSITA would be motivated to incorporate Lin's analog control method into the Bouevitch/Smith system because continuous control was a known alternative to discrete control for MEMS mirrors. The motivation would be to achieve more precise power control and channel alignment, a known benefit of analog systems. Lin specifically taught that its analog control would be useful in optical switching applications like those in Bouevitch and Smith.
    • Expectation of Success: The expectation of success was high, as incorporating analog control was one of only two known options (analog vs. discrete) for controlling MEMS mirrors, and its implementation to achieve finer control was a predictable outcome.

  • Additional Grounds: Petitioner asserted additional obviousness challenges against claim 12, which recites a specific group of wavelength-selective devices. These grounds added Dueck (Patent 6,011,884) to the primary combinations to explicitly teach the use of "ruled diffraction gratings," a species of the claimed group.

4. Key Claim Construction Positions

  • "[Controllable] in two dimensions": Petitioner argued this term should be construed to mean "in two axes," consistent with the specification's description of mirrors tilting or pivoting about two axes to deflect light.
  • "to control the power..." / "for monitoring power levels...": Petitioner contended that these and similar phrases in the apparatus claims are non-limiting statements of intended use. It argued these clauses describe what the device does rather than what the device is, and therefore add no structural limitations to the apparatus claims under the broadest reasonable interpretation standard. This position was critical, as this language was added during reissue to distinguish over Bouevitch.
  • "Continuously controllable": Petitioner proposed the construction "under analog control," based on the specification's repeated contrast between the invention's continuous adjustment and prior art discrete control, and its equation of continuous control with analog control.
  • "Servo-control assembly": Petitioner argued this term should be construed as a "feedback-based control assembly." This was based on the specification’s description of using a spectral monitor to provide "feedback" to a processing unit that then controls the mirrors.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-6, 9-13, and 15-22 of Patent RE42,368 as unpatentable.