| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser controller capable of correctly controlling individual light outputs of a plurality of laser elements depending on a variation in temperature characteristics or a temperature change among the plurality of laser elements, and to provide its control method. SOLUTION: Laser diodes (LD) 11A-11D have bias current I<SB>b</SB>applied by first current sources 14A-14D, and further modulation current I<SB>m</SB>is generated by a modulation circuit 30 and second current sources 17A-17D and superposed on the bias current I<SB>b</SB>via the modulation circuit 30 and couplers 15A-15D. A MPU 23 for controlling the first and second current sources superposes a current variationΔI as test current on the bias current and the modulation current, and controls the bias current I<SB>b</SB>of the LDs 11A-11D so that an average light output value from the LDs 11A-11D is constant depending on a light output variation of the LDs 11A-11D during the superposition. COPYRIGHT: (C)2008,JPO&INPIT
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