Impedance stabilization by trigger modulation in copper vapor laser.

A novel approach to stabilize the laser's discharge plasma impedance by trigger modulation is presented. The discharge plasma impedance of laser drops due to increased charge carriers during laser operation. The absence of intermittent high voltage discharge pulses provides enhanced time for recombining charge carriers, thus restricting the fall in the laser impedance. It has been observed that by missing 0.1% of discharge pulse, the drop in the laser voltage is improved from 4.3 to 2.3%, and an increase in the laser head current is limited to 3% from 3.6% in 6 h of laser operation. The drop in the optical output power is reduced by 10% at the end of 6 h. Further, the controlled intermittent discharge missing ceases the thermal loading at the cathode fall and lowers the probability of thermal instability in discharge plasma. This will improve the discharge stability and reduces the jitter in the metal vapor laser. We believe this approach of manipulating trigger to attain stable impedance and prevent instability, can be applied to other applications requiring high current large volume stable discharges. [ABSTRACT FROM AUTHOR]