HIGH-FREQUENCY POWER SOURCE AND LASER OSCILLATOR

摘要

PURPOSE:To set laser heads of a discharging load to an excellent impedance matching state before and after the discharge is started. CONSTITUTION:A high-frequency power source 34 comprises a high-frequency power source unit 11 having a DC power source 12 and an inverter 14, and a matching circuit 16 for supplying high-frequency power from the unit 11 to a laser gas-excited laser head 27 by high-frequency AC discharging. A PLL control unit 20 of the controller 30 detects an output voltage VA and an output current IA of the unit 11, and so PLL-controls an output frequency of the inverter 14 through an inverter control unit 23 that phases of the both substantially coincide. A phase detection signal level deciding unit 31 of the controller 30 stops control of the unit 20 of the unit 11 when the voltage VA and the current IA of the phase detection signal are less than predetermined levels, and instead fixes the output frequency of the unit 11 to an initial value F0 by a frequency initial value reference signal generator 32.