| 摘要 |
PURPOSE:To correct the fluctuation value of the ionization time of a thyratron for discharge excitation circuit, and restrain the fall fluctuation of laser output by a method wherein a processor for outputting a control signal to each variable delay circuit is provided, the processor instructs delay time, and further instructs a corrected delay time to a sequential variable delay circuit, when the time difference fluctuation between a detection signal and a repetition pulse signal is detected. CONSTITUTION:The fluctuation period of ionization time is much longer than that of the repetition frequency of excitation pulses of a laser amplifier 1a and the like, e.g., 5KHz, which is determined by a clock signal generator 7. On the contrary, at each clock signal of the clock signal generator, a processor 8 monitors the generation time of excitation pulse applied to the laser amplifier 1a, based on the detection signal from, e.g., a discharge light detector 5a. In the most rapid case, the processor corrects and sets the delay time of a variable delay circuit 6a before the next clock signal. As a result, the delay time setting of the variable delay circuit 6a and the like is capable of tracking correction of ionization time fluctuation of a thyratron 3a and the like. Thereby, the fluctuation of generation time of excitation pulse can be prevented, and the coincidence with the input timing of the pulse laser light from the pre-stage is always enabled, so that the laser light output can be kept constant. |
