Studies on Spatial, Spectral, and Energy Characteristics of Copper-HBr Laser Radiations

This paper presents, for the first time, a study on the pulse-to-pulse variation in the spatial, spectral, and energy characteristics (pointing instability, divergence, intensity, as well as the emission line-width and their fluctuations) of both green and yellow radiations of a copper-HBr laser (Cu-HBrL). The experimental study was performed in a high power (specific power: 70 W/L, total power: 72 W), 18 kHz repetition rate Cu-HBrL for different wall plug electrical input powers (6-9.5 kW) and HBr concentrations (5%-9%). These observations are supplemented with studies on near field spatial intensity and temporal profiles under all working conditions. It is observed that the characteristics are widely different for the two radiation components. The experimental observations are supported by comprehensive analysis in terms of input power coupling, laser gain and its radial distribution, thermally induced wave-front aberrations, optical noise contribution, and laser kinetics.