Invalidity dossier
US 5913000
Method and apparatus for guiding optical signals
Current assignee: Nokia of America Corp
Added 9/24/2026, 2:04:32 AM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 5,913,000
Title: Method and apparatus for guiding optical signals
Patent number: US5913000A
Application number: US08/580,951
Inventors: Christopher Richard Doerr, Martin Zirngibl, Charles H. Joyner
Original assignee (as listed): Individual; later assignments recorded to Lucent Technologies Inc. Current assignee listed as Nokia of America Corp.
Dates: Priority/filing date 1995-12-29; granted/publication date 1999-06-15; anticipated expiration 2015-12-29. Legal status: Expired – Lifetime.
Purpose (plain language): The patent addresses waveguide grating routers (AWGs) used to guide optical signals. In prior-art routers, a channel can contain multiple passbands at the same relative power, which can cause multimode lasing and unstable laser output when used in a multi-frequency laser. The invention seeks an apparatus with only one dominant passband (one peak power/frequency) per channel.
Scope (plain language): The apparatus comprises a first waveguide coupler, a second waveguide coupler, and M grated waveguides connected between them, each having a length l_m. Rather than uniform length increments, the invention controls l_m non-uniformly — e.g., l_m = (m + γ_m)Δl_t where γ_m is the deviation from a non-chirped "test" grating, and l_m ≠ l_{m+1} − Δ with Δ > 0. Length relationships use constants Δl_a (which sets channel spacing and alignment) and Δl_b (which sets envelope location, width and periodicity), with an arbitrary non-linear function g(m) determining envelope shape. Embodiments include a two-grating design (each arm split into two gratings with slightly different periods) and an "M-grating" design. Reflective mirrors may be operably connected to the grated waveguides. The result, per the described FIGS. 3A/3B and 4, is that all but one passband per channel is reduced in power.
Source: https://patents.google.com/patent/US5913000/en
What the excerpt does not establish: It is an excerpted Google Patents page (claims text is not included here), so full claim scope, the complete specification, and all drawing details are not established. Assignee data and legal status are noted by the source as assumptions, not legal conclusions.
Generated 10/1/2026, 9:30:54 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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