Patent ID: 7450844
Filing Date: 2008-11-11
Classification: H04B,H04J

Abstract:
1. WDM optical equipment comprising: a plurality of optical transmitters outputting optical signals having different wavelengths, respectively; and a multiplexer inputting the optical signals output from the plurality of optical transmitters into ports of the corresponding wavelengths, and multiplexing the optical signals, each of the plurality of optical transmitters including; wherein when the standby panel is reset during the active panel being in operation the standby optical transmission circuit is set to output an optical signal having a wavelength different from a wavelength of an optical signal output from the active optical transmission circuit, and an attenuation amount of the standby attenuator is set to the maximum, and subsequently, the wavelength of the optical signal output of the standby optical transmission circuit is set to a target wavelength identical to the wavelength of the optical signal output from the active optical transmission circuit; and an optical amplifier controlling to maintain a level of the optical signals multiplexed by the multiplexer to be constant, wherein the active and standby optical transmission circuits include laser diodes having characteristics such that wavelengths of optical signals emitted from the laser diodes vary with the temperature, and when controlling the attenuation amount of the attenuator in the standby optical transmission circuit to the maximum, the laser diode in the standby optical transmission circuit is either heated or cooled so as to enable the laser diode to output an optical signal having a wavelength in an opposite direction relative to the center of the wavelength control range determined by the temperature at time of resetting, to the wavelength of the optical signal output from the corresponding active optical transmission circuit so as to output the optical signal of the target wavelength.