| 摘要 |
PURPOSE:To eliminate the need for temperature control by a Peltier element, etc., and to stabilize the memory of optical informations by controlling currents fed to an electrode on the loss region side of a bistable semiconductor laser on the basis of the temperature of an active layer. CONSTITUTION:A transistor 201 is fitted adjoined to a laser 200 so as to be kept at the same temperature as the bistable semiconductor laser 200. When the current value IC of a constant current circuit 202 is kept constant, the temperature T of an active layer in the bistable semiconductor laser 200 can be detected by the base-emitter voltage VBE of the transistor 201. A voltage detecting circuit 203 controls the current value i2 of a variable current circuit 207 in response to the base-emitter voltage VBE of the transistor 201, and reduces the current value i2 of the variable current circuit 207 in response to the rise of the base-emitter voltage VBE of the transistor 201 when base-emitter voltage VBE rises. The input/output characteristics of the voltage detecting circuit 203 are determined so that the temperature change of the i1-Pout characteristics of the bistable semiconductor laser and a current value offsetting the change of said characteristics by i2 are generated in the variable constant-current circuit 207. |
