Patent ID: 6323976
Filing Date: 2001-11-27
Classification: H04B

Abstract:
A light source device for frequency division multiplexed optical communications, comprising:a first light source for outputting light having a frequency which oscillates at a first modulation frequency centered about a first optical frequency;first splitting means for splitting output light from said first light source into two parts, and outputting one part to an output end;a second light source for outputting light having a frequency which oscillates at a second modulation frequency different from said first modulation frequency centered about a second optical frequency different from said first optical frequency;second splitting means for splitting output light from said second light source into two parts, and outputting one part to the output end;multiplexing means for receiving and multiplexing the other parts of the light outputted by said first splitting means and said second splitting means;transmitting means for transmitting the respective components of light in the output of said multiplexing means at specified transmission rates corresponding to the optical frequencies of said components of light;light receiving means for detecting the output light transmitted by said transmitting means;first control means comprising a bandpass filter for receiving an output signal from said light receiving means and outputting only a signal having the first modulation frequency corresponding to said first light source, a phase detector for phase-detecting the frequency component at said first modulation frequency in the output signal from said light receiving means with a signal of said first modulation frequency from said first light source as a reference signal, and controlling said first light source by feedback such that the output of the phase detection is held at zero; andsecond control means comprising a bandpass filter for receiving an output signal from said light receiving means and outputting only a signal having the second modulation frequency corresponding to said second light source, a phase detector for phase-detecting the frequency component at said second modulation frequency in the output signal from said light receiving means with a signal of said second modulation frequency from said second light source as a reference signal, and controlling said second light source by feedback such that the output of the phase detection is held at zero.