Patent ID: 7398021

Claim:
An optical transmitter comprising: a multi-lambda source to output injection light consisting of a plurality of injection channels; a circulator having a first port, a second port, and a third port, the circulator receiving the injection light at the first port, outputting the received injection light to the second port, receiving signal light at the second port, and outputting the received signal light to the third port; an arrayed waveguide grating having a multiplexing port connected to the second port of the circulator, and a plurality of demultiplexing ports, the circulator receiving the injection light at the multiplexing port, spectrum-slicing the received injection light into a plurality of injection channels, and outputting the injection channels to the demultiplexing ports, respectively, and receiving a plurality of signal channels at the demultiplexing ports, respectively, multiplexing the received signal channels into signal light, and outputting the signal light to the multiplexing port; and a plurality of reflective semiconductor optical amplifiers connected to the demultiplexing ports of the arrayed waveguide grating, each of the reflective semiconductor optical amplifiers receiving an associated one of the injection channels, and amplifying the associated injection channel to generate an associated one of the signal channels, wherein the arrayed waveguide grating has a transmission line width equal to or larger than a line width of each injection channel.