| 摘要 |
PURPOSE:To increase the speed of response of the control of an optical output, to remove the difference of optical outputs on a continuous output and on pulse modulation while lowering loss in a control system and to reduce power consumption by detecting the peak value of laser output beams and comparing the peak value with a reference signal. CONSTITUTION:A gate is opened only when there is an output from a laser diode 1 in a gate circuit 3, and the gate circuit 3 is synchronized with a pulse modulation circuit 9, thus operating the gate circuit 3 so as to prevent the leakage of a peak-output detection circuit 4. The peak output detection circuit 4 detects the peak value of laser output beams 11 from the laser diode 1 and transmits it over a comparator 5, compares it with the reference voltage Vs of a reference supply 6, and controls a current control circuit 7 by a control signal 13 on the basis of the comparison. Accordingly, speed detection-responding to the fluctuation of a laser output is increased, the difference of optical outputs on a continuous output and on pulse modulation is removed while the loss of a control system is lowered, and power consumption can be reduced. |
