| 摘要 |
PURPOSE:To control the temperature of a semiconductor laser device highly stably at a high speed by switching off temperature control of an auxiliary temperature control circuit to an auxiliary heater by an output temperature detection signal by means of limiting means. CONSTITUTION:A limiter circuit 22 is adapted to be controlled in its operation by a difference V between temperature detection voltage V2 from a differential unit 21 and set voltage V0. Insofar as the difference V does not exceed a preset value, a control current from a second temperature controller 20 is allowed to pass through as it is and outputted, whereas if the difference V exceeds the preset value, the control current is interrupted in its passage. Accordingly, an auxiliary heater 13 is heated by the control current passing through the limiter circuit 22 upon ordinary sweeping of wavelength to change the temperature of the semiconductor laser 1 device to a given value responsive to the set voltage V0. Herein, the temperature detection voltage V2 changes following up the change in the laser current to permit the temperature of the auxiliary heater 13 to also change correspondingly at a high speed. |
