Oyster Optics, LLC v. Infinera Corporation, Coriant (USA) Inc., Coriant North America, LLC and Coriant Operations, Inc.

CourtDistrict Court, E.D. Texas
DecidedJuly 23, 2020
Docket2:19-cv-00257
StatusUnknown

This text of Oyster Optics, LLC v. Infinera Corporation, Coriant (USA) Inc., Coriant North America, LLC and Coriant Operations, Inc. (Oyster Optics, LLC v. Infinera Corporation, Coriant (USA) Inc., Coriant North America, LLC and Coriant Operations, Inc.) is published on Counsel Stack Legal Research, covering District Court, E.D. Texas primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Oyster Optics, LLC v. Infinera Corporation, Coriant (USA) Inc., Coriant North America, LLC and Coriant Operations, Inc., (E.D. Tex. 2020).

Opinion

IN THE UNITED STATES DISTRICT COURT FOR THE EASTERN DISTRICT OF TEXAS MARSHALL DIVISION OYSTER OPTICS, LLC, § § Plaintiff, § v. § § INFINERA CORPORATION, CORIANT § Case No. 2:19-cv-00257-JRG (USA) INC., CORIANT NORTH § AMERICA, LLC, and CORIANT § OPERATIONS, INC., § Defendants. § CLAIM CONSTRUCTION MEMORANDUM OPINION AND ORDER In this case, Oyster Optics, LLC, alleges Infinera Corporation, Coriant (USA) Inc., Coriant North America, LLC, and Coriant Operations, Inc., (collectively, “Defendants”) infringe certain claims of U.S. Patent No. 6,665,500 (the “’500 Patent”). The abstract of the’500 Patent describes it as concerning a fiber optic telecommunications system and method that each create phase-modulated optical signals from a data stream in one mode and amplitude-modulated optical signals from a data stream in another mode. The parties dispute only one aspect of claim scope: whether the claimed inventions exclude the use of amplitude modulation when operating in the phase-modulation mode. Having considered the parties’ claim-construction briefing, the Court concludes such a broad exclusion is not proper. I. BACKGROUND A. The ’500 Patent According to the ’500 Patent, prior-art fiber optic networks included a laser, an amplitude

modulator that “pulses or alters the laser output to create an amplitude-modulated optical signal representative of [an] electronic data stream,” and a receiver that “typically includes a photodiode to convert the optical signals back into the electronic data stream.” ’500 Patent at 1:12–22. The patent characterizes the laser and amplitude modulator together as “a transmitter for transmitting the optical signal over an optical fiber” to the receiver. Id. at 1:16–19. But these types of networks are vulnerable to “tapping”: [O]ptical fibers can be spliced or even merely clamped so as to obtain optical signals from the fiber. It also may be possible to tap fibers without physically touching the optical fiber, for example by reading energy emanating or dissipating along the fiber. Amplitude-modulated optical signals, with their ease of detection from a photodiode, require that only a small amount of energy be tapped and passed through the photodiode in order to be converted into a tapped electronic data stream. Id. at 1:28–37. The patent describes a number of prior-art references that attempt to address this vulnerability using phase modulation rather than amplitude modulation, but ultimately concludes the teachings of those references are not compatible with existing receivers. See id. at 1:57–2:22. To address this lack of compatibility, the ’500 Patent teaches a system and method for transmitting and receiving either phase-modulated or amplitude-modulated signals. Id. at 4:4–20. More specifically, the patent describes using one of three transmission modes: phase-modulation, amplitude-modulation, or both phase- and amplitude-modulation. Id. at 2:41–44. Each of the claims recites using amplitude modulation in one mode and phase modulation in another mode. For example, Claim 1 recites: An optical data transmitter comprising: a laser; a phase modulator for phase modulating light from the light source; and a controller having an input for receiving an electronic data stream, the controller in a first mode controlling the phase modulator so as to create phase-modulated optical signals in the light from the laser as a function of the electronic data stream and the con- troller in a second alternate mode amplitude-modulating the light from the laser as a function of the electronic data stream, the first mode and the second mode occurring at different times. Id. at 8:29–40 (emphasis added). Claim 16 similarly recites: A dual-mode optical transmission system comprising: a transmitter having a laser for transmitting amplitude- modulated signals in a first mode and phase-modulated signals in a second mode and a controller for switching an output of the laser between the first mode and the second mode, the second mode occurring at a different time than the first mode; an optical fiber connected to the transmitter; and a receiver having an interferometer being connected to the optical fiber. Id. at 10:1–11 (emphasis added). And method Claim 17 requires: phase modulating light from a laser during a first transmission mode so as to transmit phase-modulated optical data; and amplitude modulating light from the laser during a second alternate transmission mode so as to transmit amplitude-modulated opti- cal data, the second alternate transmission mode occurring at a time separate from the first transmission mode. Id. at 10:14–21 (emphasis added). The parties now dispute whether the claimed invention excludes the use of any amplitude modulation during the phase-modulation mode. Oyster claims the ’500 Patent provides no intrinsic reasoning for such an exclusion. Defendants, on the other hand, contend the ’500 Patent so dispar- ages amplitude modulation that exclusion is warranted, which aligns with the Court’s construction

of “phase modulate” in other litigation between these parties. Defendants also argue prosecution history and two forms of estoppel support their proposed construction. B. The Related Litigation This is not a new dispute to these parties. They first contested the meaning of “phase mod- ulate” in Oyster Optics, LLC v. Coriant Am. Inc. et al., No. 2:16-cv-01302-JRG (“Oyster I”), a lawsuit concerning seven patents that also relate to fiber optic data systems and have the same named inventor as the ’500 Patent. Three of the Oyster I patents concern “phase-modulated fiber optic telecommunications system[s]” intended to “improv[e] security and data transmission over fiber optic networks.” U.S. Patent No. 6,469,816 at (54), 1:14–16; see also U.S. Patent No.

6,594,055 at (54), 1:9–11; U.S. Patent 6,476,952 No. at (54), 1:14–16. The other four patents dis- close embodiments of fiber optic transceiver cards “for providing secure optical data transmission over optical fiber.” U.S. Patent No. 7,620,327 at 2:18–20; see also U.S. Patent No. 6,476,952 at 2:27–28; U.S. Patent No. 8,374,511 at 2:22–24; U.S. Patent No. 8,913,898 at 2:24–26. In Oyster I, Defendants argued “phase modulate” should exclude amplitude modulation for three reasons. First, the Oyster I patents expressly describe “phase-modulated signals” as having constant amplitude. Dkt. No. 73-4 at 11. Second, varying the amplitude during phase modulation defeats the purpose of the inventions by exposing the data to photodiode optical taps. Id. at 11–13. Third, the specifications consistently disparage amplitude-modulated signals as easily tapped. Id. at 13–14. Oyster, however, argued “phase modulate” should not exclude amplitude modulation, relying on expert testimony, the doctrine of claim differentiation, and excerpts from the specifications stating that amplitude-modulated transmitters could be used. Dkt. No. 73-5 at 5–6. Ultimately, Chief Judge Gilstrap held that phase modulation, as used in the claims of the Oyster I patents, required “keeping the amplitude of the light constant . . . .” Dkt. No. 73-6 at 18.

Judge Gilstrap reasoned that the patents repeatedly distinguish between phase modulation and amplitude modulation and “disparage amplitude-modulated optical signals as being easily tapped.” Id. at 14. Thus, wrote Judge Gilstrap, “the specification explains that the desired benefits of phase modulation are obtained only in the absence of amplitude modulation.” Id. at 17 (citing ’898 Patent at 4:44–52). The Court acknowledged that amplitude and phase modulation were not necessarily mutually exclusive. Id. at 16. But the Court concluded that “on balance, in light of the disparagement of prior art involving amplitude modulation, and in light of the disclosures of the advantages of using phase modulation instead of amplitude modulation, the ‘phase modulate’ terms should be interpreted so as to exclude amplitude modulation.” Id. at 17.

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Oyster Optics, LLC v. Infinera Corporation, Coriant (USA) Inc., Coriant North America, LLC and Coriant Operations, Inc., Counsel Stack Legal Research, https://law.counselstack.com/opinion/oyster-optics-llc-v-infinera-corporation-coriant-usa-inc-coriant-txed-2020.