Optical transmitter

An optical transmitter used for a time and wavelength division multiplexing system, comprising:

• a FP-LD, for generating and outputting multiple-longitudinal mode light wave, wherein the FP-LD is also driven by an electrical signal, and modulating the electrical signal to an optical carrier;
• an optical coupler, coupled with the FP-LD, wherein the optical coupler is used for feeding the multiple-longitudinal mode light wave from the FP-LD to a fiber Bragg grating with tunable wavelength;
• the fiber Bragg grating with tunable wavelength is for filtering the received multiple-longitudinal mode light wave according to a predetermined parameter, and feeding back the optical signal generated after being filtered to the optical coupler;
• the optical coupler is for dividing the optical signal to a first branch optical signal and a second branch optical signal, wherein, the first branch optical signal is fed back to the FP-LD, and the second branch optical signal is fed to a detector;
• the detector is used for judging whether the wavelength and power of the second branch optical signal meet a predetermined condition;
• when the predetermined condition is not met, the FP-LD reflects the first branch optical signal to the optical coupler, and the optical coupler, the fiber Bragg grating with tunable wavelength, the optical coupler and the detector in turn repeat respectively the operations of the feeding, the filtering and feedback, the dividing and the judging;
• when the predetermined condition is met, the detector outputs the second branch optical signal to an output port of the optical transmitter;
• wherein, the optical transmitter further includes a controller, the controller is used for receiving a control signal from an optical line terminal, and adjusting the predetermined parameter of the fiber Bragg grating with tunable wavelength according to the control signal.