Excimer laser performance under various microwave excitation conditions

摘要

Abstract: Microwave pumped rare-gas halide mixtures feature excimer laser emission without preionization. The performance of a XeCl excimer laser is investigated with an optimized waveguide coupling geometry. Parameters such as the microwave power, duration of the microwave pulse, and the rise time of the microwave pulse from 25 ns to 220 ns were varied. The pulsed microwave L-band transmitter had a power of up to 10 MW, an adjustable pulse duration (500 ns to 6000 ns), and a pulse repetition frequency up to 400 Hz. The coupling geometry consisted of a double ridge waveguide. The discharge tube was a quartz capillary placed between the ridges. Two tubes were used. One had an outer and inner diameter of 10.3 mm and 2.6 mm, the other 8 mm and 5.8 mm, respectively. The total active length was 438 mm. A study of a microwave power of 2.5 MW deposited into the discharge yielded at low repetition frequencies a non-homogeneous deposition. With a new resonant coupling geometry, a XeCl laser energy of up to 1.8 mJ in a 16 ns long pulse was achieved.!