Laser oscillator circuit

Abstract

A discharge pumping circuit of spiker/sustainer type for the Excimer laser oscillator, wherein spiker unit is isolated from the sustainer unit by a switching device such as a magnetic isolator is disclosed. In the pumping circuit, the switching device shifts from its OFF state to its ON state, during the process of charging a spiker capacitor, before its terminal voltage reaches a voltage which initiates the discharge, and a sharp-rise pulse voltage is applied by a transfer of electric charge from said sustainer capacitor to said spiker capacitor, to initiate the discharge for the pumping. In another discharge-pumping circuit which also has a means for preionizing the laser gas, the timing for the preionization is set to start after the initiation of charging the sustainer capacitor and before the initiation of charging the spiker capacitor in a polarity opposite to that of the sustainer capacitor, and is controlled for maintaining the discharge initiating voltage constant for the repetition frequency. In another discharge-pumping circuit, a power source for charging the sustainer capacitor is structured to include a magnetic pulse compression circuit to reduce the stress on a high voltage switch such as a thyratron in the circuit to realize an excellent performance, a long service life and a high reliability.