OPTICAL RECEIVER

摘要

PROBLEM TO BE SOLVED: To obtain an output signal current stable at all times by adhering a Peltier element and a temperature sensor to a heat sink on which a light receiving element is closely fixed and controlling drive of the Peltier element so as to make the temperature of the heat sink constant based on a sensed temperature of the temperature sensor thereby keeping the temperature of the light receiving element constant even when ambient temperature changes. SOLUTION: A Peltier element 13 and a temperature sensor 14 are adhered to a heat sink 12 to which a light receiving element 11 is adhered closely. The temperature sensor 14 senses a temperature of the heat sink 12. The detection signal is fed to an arithmetic circuit 15, where a current to be supplied to the Pettier element 13 is calculated so that the heat sink 12 reaches a preset temperature. A Peltier element drive circuit 16 drives the Pettier element 13 based on the calculation result. The Peltier element 13 conducts heating/cooling based on the current flowing therethrough to keep the temperature of the heat sink 12 constant. Thus, the light receiving element 11 adhered closely to the heat sink 12 is kept to be at a constant temperature.