Patent ID: 7535940
Filing Date: 2009-05-19
Classification: H01S

Abstract:
1. An optical transmitter, comprising: a laser diode; a laser driver for driving the laser diode; a thermoelectric controller for controlling a temperature of the laser diode; a TEC driver for driving the thermoelectric controller by receiving a temperature monitor signal corresponding to the temperature of the laser diode and a target signal corresponding to the target temperature of the laser diode, the TEC driver outputting an error signal corresponding to a difference between the temperature monitor signal and the target signal; and a master controller, by receiving the error signal output from the TEC driver, for generating a driver enable signal to enable the laser driver when the error signal output from the TEC driver is within a first convergent range and a rate of change of the error signal is within a second convergent range, wherein the master controller includes a range monitor, a slope monitor, a driver controller, and a memory, the range monitor enabling a first signal when the error signal output from the TEC driver is within the first convergent range and outputting the first signal to the driver controller, the slope monitor enabling a second signal when the rate of change of the error signal is within the second convergent range and outputting the second signal to the driver controller, the driver controller outputting the driver enable signal when the first signal and the second signal are both enabled, the memory storing an error signal previously compared by the TEC driver, and wherein the slope monitor calculates the rate of the change of the error signal by subtracting the error signal currently input from the TEC driver from the error signal previously input and stored in the memory.