LASER EMITTING POWER CONTROL METHOD AND LASER DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of noise in a laser device which feedback controls emitting power of laser beams. SOLUTION: The laser device is provided with a laser beam source 1, a laser modulator (EMO: electro optical modulator) 4 which variably controls the transmissivity of laser beams 11 emitted from the light source 1 and a control circuit (ALC: auto laser power control) 8 which detects output levels of the laser beams outputted from the EOM4 and outputs a bias voltage Vb to variably control the transmissivity of the EOM4. The ALC 8 controls the voltage Vb so that the output of the EOM4 becomes a beforehand set output. The laser device is also provided with a noise detecting circuit 9 which detects noise in the laser light beams outputted from the EOM4 and outputs power fine adjusting signals Sp and a laser light beam level varying means (a laser power supply 2) which changes output levels of the laser beams that are outputted from the laser beam source 1 and made incident on the EOM4 when the signals Sp are received.