Laser driving device

Abstract

Abstract PURPOSE:To stop sweeping of a gradually increasing current generating means when output of a photodetector reached the prescribed value, and to hold wave length of a laser oscillation at the prescribed value by a method wherein the gradually increasing current generating means and a means to decide that the output of the detector has reached the prescribed value are added to a control electric power source. CONSTITUTION:Laser rays of wave length corresponding to a driving current I supplied from a control electric power source 10 are oscillated from a semiconductor laser device containing a spectral means 1. An output voltage Vsh of the laser rays thereof is compared with a reference voltage VR by a comparator 5, the outputted level is judged, and the judged result thereof is applied to an AND circuit 6 of the electric power source 10. Output of a pulse generator 8 is applied to another input of the circuit 6 thereof, and a clock voltage V0 is applied to a counter 7 when the judged result is in H level. The voltage V0 is increased gradually by the counter 7 thereof according to voltages supplied from terminals 12, 13, and is applied to a D/A converter 9, a gradually increasing analog voltage Vd is generated, and the current I is outputted from an electric power source 11. When the output of the comparator 5 reached the prescribed value, sweeping of the counter 7 is stopped to make oscillating wave length at the prescribed value.

Inventors

• 👤 Shoji Doi
• 👤 土肥　正二
• 👤 Isao Tofuku
• 👤 東福　勲
• 👤 Hiroyuki Ishizaki
• 👤 石崎　洋之

Bibliographic Details