Optical multiplexing circuit and light source
AssigneeNippon Telegraph and Telephone Corporation
InventorsJunji Sakamoto, Toshikazu Hashimoto
Life of this patent
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Abstract
To provide an optical multiplexing circuit that can accurately monitor light of a plurality of wavelengths, and that can tolerate degradation of LDs. An optical multiplexing circuit includes m sets of multiplexers configured to multiplex light output from n connection waveguides being a plurality of connection waveguides wherein a multiplexing unit configured to input and multiplex light output from the m sets of the multiplexers from m input waveguides, an output waveguide configured to output light multiplexed by the multiplexing unit, and n×m or m branching units being inserted into n×m connection waveguides of the plurality of connection waveguides or the m input waveguides are provided on a same substrate.
Claims5
A light source with a monitoring function, comprising:
- m sets of multiplexers configured to multiplex light output from n connection waveguides being a plurality of connection waveguides,
- a multiplexing unit configured to input and multiplex light output from the m sets of the multiplexers from m input waveguides,
- an output waveguide configured to output light multiplexed by the multiplexing unit,
- n×m or m branching units being inserted into n×m connection waveguides of the plurality of connection waveguides or the m input waveguides,
- n×m laser diodes each optically coupled to a corresponding one of the connection waveguides, the n×m laser diodes being mounted to a laser diode mount that is separte from a substrate that mounts the m sets of multiplexers, the n connection waveguides, the output waveguide, and the n×m or m branching units,
- wherein a first one of the n×m laser diodes is configured as an active laser diode and a second one of the n×m laser diodes is configured as a standby laser diode, the monitoring function configured to:
- detect a degradation in an operation of the first one of the n×m laser diodes, and
- in response, switch to the operation of the second one of the n×m laser diodes by moving the laser diode mount such that a fixed position occupied by the first one of the n×m laser diodes before the laser diode mount is moved is occupied by the second one of the n×m laser diodes after the laser diode mount is moved.
Dependencies are inferred from the claim text.