SEMICONDUCTOR LASER DRIVE CIRCUIT

To provide a semiconductor laser drive circuit capable of performing APC control at high speed.SOLUTION: A semiconductor laser drive circuit includes: a plurality of semiconductor laser LD1-LDN connected in series; a current source 2 from which current flows to the plurality of semiconductor laser; a current source drive circuit 3 which drives the current source to control current of the current source; detection means 5 for detecting laser light from the plurality of semiconductor laser; a current control element 4 connected from the final semiconductor laser LDN among the plurality of semiconductor laser to one or more semiconductor laser including the final semiconductor laser; and a current quantity control circuit 6 which controls the current control element on the basis of output of the detection means to control current quantities of one or more semiconductor laser.SELECTED DRAWING: Figure 1 【課題】高速にＡＰＣ制御できる半導体レーザ駆動回路を提供する。【解決手段】直列に接続された複数の半導体レーザＬＤ１〜ＬＤＮと、複数の半導体レーザに電流を流す電流源２と、電流源を駆動して電流源の電流を制御する電流源駆動回路３と、複数の半導体レーザからのレーザ光を検出する検出手段５と、複数の半導体レーザの内の最後の半導体レーザＬＤＮから最後の半導体レーザを含む１個以上の半導体レーザに接続された電流制御素子４と、検出手段の出力に基づき電流制御素子を制御することにより１個以上の半導体レーザの電流量を制御する電流量制御回路６とを備える。【選択図】図１