| 摘要 |
PURPOSE:To eliminate the need for providing individually a temperature detecting element and to contrive an increase in the reliability of an optical transmitter by a method wherein the temperature of a light-emitting element is detected from the output signal of a photodetector. CONSTITUTION:An optical transmitter is constituted of a light-emitting element 3, a driving circuit 1 of the element 3 consisting of transistors 11 and 12, a photodetector 4, which is housed in the same package as that of the element 3 and monitors part of the luminescent power of the element 3, a temperature detecting circuit 15 consisting of a low-pass filter 13 for inputting a monitoring current and a first amplifying circuit 14, a luminescent power control circuit 16 for inputting similarly the monitoring current, a Peltier element 9 and a temperature control circuit 8. The temperature of the element 3 is detected by the output signal of the circuit 14 connected to the filter 13. Thereby, a detection of the correct temperature of the light-emitting element is made possible and a highly reliable optical transmitter can be obtained. |
