Spectral structure of CuBr vapor laser lines

Studies on the spectral purity of copper–hydrogen bromide laser radiations

“…The rate of increase of the linewidth of the yellow component was higher as compared to that of the green component. These results can be readily compared with those of an elemental CVL of ∼7 and ∼11 GHz and a CuBr laser of 5-6 GHz and 6-8 GHz, respectively, for the green and yellow lines [17,20,21]. Similarly, the variation in linewidths of the green and yellow lines with different levels in HBr concentration, taken at a wall plug electrical input of ∼8 kW, is shown in Fig.…”

“…In addition, several hyperfine transitions originate from the same hyperfine upper level, which lead to gain completion among the transition components. Experimentally, it was observed in a CuBr laser (without any hydrogen additive) that in standard operating conditions, the green line displays a single complex line shape, while the yellow line displays several distinct components [20,21]. Therefore, it is possible that as the input power coupled to the discharge increased, the local fluctuations, such as temperature and refractive indices, etc., also increased.…”

“…These two approximations basically differ in terms of exclusion/inclusion of hyperfine splitting of the energy levels and isotope shifts of copper [28]. The linewidth-governing major intrinsic physical processes in a CVL/Cu-HBrL are isotope shift, hyperfine splitting of the laser levels, and their broadening as well as gain distribution effects, associated with the radiating copper atoms [17,20,21,28]. The broadening effects in a Cu-HBrL include both homogenous and inhomogeneous components.…”

“…In this context, it is highly essential to carry out a study on the spectral linewidth and frequency characteristics of a Cu-HBrL. In the literature, few studies on the linewidth issues are reported in elemental CVLs (operating temperature, ∼1500°C; gas mixture, copper neon) and copper bromide/chloride lasers (operating temperature, ∼500°C; gas mixture, copper bromide∕chloride neon), at threshold or very low laser output power and using a Fabry-Perot interferometer [17][18][19][20][21][22]. However, these spectral purity aspects have not been reported in the case of a Cu-HBrL in general, and in particular for high average laser power levels.…”