| CPC H04B 10/077 (2013.01) [H04B 10/503 (2013.01); H04B 10/516 (2013.01); H04J 14/02 (2013.01)] | 8 Claims |
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7. An optical access system comprising:
an optical transmitting device; and
an optical receiving device, wherein
the optical transmitting device includes
a plurality of optical transmitters configured to output optical signals with different wavelengths,
a multiplexer configured to wavelength-multiplex the plurality of the optical signals output from the plurality of optical transmitters, and
an amplifier configured to amplify the wavelength-multiplexed optical signal,
wherein
the plurality of optical transmitters each include
a monitoring control signal applicator configured to add a monitoring control signal to a constant current for driving a laser to generate a driving signal and apply the driving signal to the laser, the monitoring control signal being a same signal at the plurality of optical transmitters and including information on free wavelength,
a laser configured to output an optical signal in accordance with the driving signal applied to the monitoring control signal applicator, and
a modulator configured to modulate the optical signal output from the laser with a main signal, and
wherein
the optical receiving device includes
a photoelectric converter configured to convert the optical signal into an electric signal, and
a demodulator configured to demodulate the monitoring control signal based on the electric signal,
wherein the optical transmitting device further comprises a synchronizer synchronizes the plurality of monitoring control signal applicators,
wherein the plurality of monitoring control signal applicators apply the driving signal at the same timing to different lasers in accordance with synchronization signals for synchronizing an application timing of the driving signal supplied from the synchronizer,
the amplifier is an Erbium Doped Fiber Amplifier (EDFA) and is operated in a saturation region of a gain.
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