METHOD OF CONTROLLING IN STABLE FASHION PULSE LIGHT SOURCE AND PHASE DIFFERENCE OF PULSE LASER LIGHT

摘要

A pulse light source (1) according to the present invention comprises: a master laser (112); a slave laser (212); a phase comparator (232); a loop filter (234); an adder (235); and a phase comparator (306). The master laser (112) detects a master laser light pulse whose repetition frequency is controlled to a prescribed value. The slave laser (212) outputs a slave laser light pulse. The phase comparator (232) detects the phase difference of an electrical signal of a frequency of a prescribed value and an electrical signal based on the optical intensity of the slave laser light pulse. The adder (235) adds a repetition frequency control signal having a fixed repetition frequency to the output of the loop filter (234). The phase comparator (306) measures the phase difference between pulses, constituting the phase difference of the master laser light pulse and the slave laser light pulse. The repetition frequency of the slave laser light pulse is varied in accordance with the output of the adder (235). The magnitude of the repetition frequency control signal is controlled so that the measured phase difference between pulses matches the target value of the phase difference between pulses.