Title :
Transverse mode propagation and gain coefficients in a planar waveguide CO2 laser amplifier
Author :
Cao, Qiusheng ; Baker, Howard J. ; Hall, Denis R.
Author_Institution :
Dept. of Phys., Heriot-Watt Univ., Edinburgh, UK
fDate :
3/1/2001 12:00:00 AM
Abstract :
The transverse mode propagation and amplification characteristics of a large electrode area, planar waveguide carbon dioxide laser amplifier have been investigated. Amplification of an imperfectly mode-matched input produces varying output beam quality with changing discharge conditions, through the modification of the propagation constants of the waveguide modes by the gas thermal lens. For improved mode-matching to the amplifier, a near ideal TE1 output is obtained without discharge-induced variations. The maximum gain coefficient for propagation in the fundamental mode is shown to be dependent on the radio frequency discharge conditions through the frequency dependence of the minimum stable power density. At 81 MHz, a gain coefficient of 0.65 m-1 at 50 torr pressure is obtained
Keywords :
carbon compounds; gain measurement; gas lasers; high-frequency discharges; laser beams; laser modes; laser variables measurement; lenses; mode matching; nonlinear optics; optical planar waveguides; waveguide lasers; 50 torr; 81 MHz; CO2; CO2 laser amplifier; amplification characteristics; discharge conditions; frequency dependence; fundamental mode; gain coefficient; gain coefficients; gas thermal lens; imperfectly mode-matched input; large electrode area; maximum gain coefficient; minimum stable power density; mode-matching; near ideal TE1 output; planar waveguide laser amplifier; propagation; propagation constants; radio frequency discharge conditions; transverse mode propagation; varying output beam quality; waveguide modes; Carbon dioxide; Electrodes; Gas lasers; Laser beams; Laser modes; Optical propagation; Planar waveguides; Propagation constant; Thermal lensing; Waveguide lasers;
Journal_Title :
Quantum Electronics, IEEE Journal of
