High-efficiency operation of a gas discharge XeCl laser using a magnetically induced resonant voltage overshoot circuit

Abstract

An electrical to optical efficiency of 5% has been demonstrated in an x-ray preionized XeCl discharge laser using an improved prepulse-mainpulse circuit, based on resonant charging of the peaking capacitor. In contrast to known prepulse-mainpulse circuits, the new scheme has no time delay between prepulse and mainpulse nor a voltage reversal on the electrodes. We present three possible configurations of the scheme and one of them has been realized for demonstrating its high-efficiency capabilities.

<title>High-average power XeCl laser with x-ray preionization and spiker-sustainer excitation</title>

“…We also investigated the performance of the pre-pulse-main-pulse circuit. This circuit, figure 5, can operate in two modes called the 'resonant overshoot' mode [13] and the 'charge' mode [15] respectively. 'Resonant overshoot' mode is obtained when the pre-pulse is triggered at about the reversal of the charging current.…”

“…A number of electrical circuits and modes of operation has been studied during the course of the project [13,14,15]. Application of x-ray switching [16], where the pre pulse circuit and the main switch can be omitted simplifies the circuit significantly.…”

The influence of charge-mode operation of a XeCl laser on the beam profile

“…2 shows the electrical circuit schematically. The laser could operate in the 'resonant overshoot mode' [6] and in the 'charge mode' [7]. The spiker circuit includes a one-step pulse compression circuit that has two functions: Firstly, it increases the rise time and duration of the current pulse through the spiker thyratron which helps to increase the life time of this thyratron at high repetition rate operation and secondly it plays an important role when the circuit operates in the charge mode.…”

Optimisation of the pulse duration of a discharge-pumped XeF(B?X) excimer laser

“…There are a number of factors such as the electrical circuit, halogen concentration, total pressure, output coupling mirror transmission and electrical energy deposition which influence the rare-gas halide laserpulse duration. Recently, the use of magnetic-spiker sustainer excitation circuits for XeC1 rare-gas halide lasers has resulted in a higher efficiency, longer optical pulse durations and higher beam quality compared to conventional electrical discharge excitation circuits [1][2][3]. …”