Operation of an unstable resonator TE CO2 laser with large electrode spacing using additives
Authors:
G. Salvetti
Affiliation:
Department of Applied Physics, University of Hull, Hull, HU6 7RX, UK
Abstract:
A study of a pulsed transversely excited (TE) CO2 laser using an unstable resonator configuration is reported. It is shown that a large aperture (4.75 cm) wire-triggered device can successfully operate at pressures of up to 650 torr with undoped gas mixtures whose molecular gas concentration exceeds 35%. These results are utilised for a comparative study of the influence of an organic additive on the performance of the system. It is observed that the addition of traces of tri-n-propylamine leads to significant improvements of the laser output characteristics even under conditions where a glow discharge could be obtained without the additive. With the doped TE CO2 laser employed using a relatively low magnification unstable resonator (M = 1.45) near diffraction-limited performance has been achieved and a peak radiance of 4.5 × 1013 W cm−2 sr−1 has been obtained with a peak power of 65 MW.