Microwave discharge has been proposed for high power laser oscillator. However, there are few practical high power (over 1 kW) microwave excited carbon-dioxide laser oscillator since it is difficult to establish a homogeneous discharge region across and along a laser tube for coaxial fast gas flow laser. This paper proposes a practical high power microwave excited carbon-dioxide laser oscillator by (1) employing orthogonal crossing electric field for radial homogeneity of the discharge, (2) dividing the axial discharge region of the laser tube into several discharge sections for stable discharge, and (3) selecting the optimized gas flow to maximize the laser output laser power. Applying these technologies, the experimental apparatus achieved 270 W laser output at 1.4 kW input microwave power per the waveguide. The equipment is also able to scale up by connecting tubes, which consist of five waveguides per tube, and confirmed 1.8 kW for the same volumetric gas flow rate and the structure of a conventional 1.8 kW dc laser. The proposed methods may provide a practical high power microwave excited carbon-dioxide laser oscillator that exceeds the conventional dc discharge one.

Date Published: 4 April 1997
PDF: 5 pages
Proc. SPIE 3092, XI International Symposium on Gas Flow and Chemical Lasers and High-Power Laser Conference, (4 April 1997); doi: 10.1117/12.270218

Published in SPIE Proceedings Vol. 3092:
XI International Symposium on Gas Flow and Chemical Lasers and High-Power Laser Conference
Denis R. Hall; Howard J. Baker, Editor(s)