Copper chloride vapor laser. Processes limiting the output power

Abstract

An experimental investigation was made of transient processes in a CuCl laser, excited by trains of electric discharge pulses. It was found that the lasing parameters were determined mainly by the diffusion processes feeding the CuCl the discharge zone and causing the copper atoms to migrate to the walls. It was proved experimentally that the reduction in the laser output power at temperatures above the melting point of CuCl (~430°C), observed when the copper chloride was located directly in the discharge zone, was caused by the loss of the optical transparency of the active medium due to the scattering by CuCl droplets which appeared in the gas under the action of the discharge. A discharge tube design was proposed and realized in which the medium remained transparent up to 600°C (for a fivefold increase in the average laser output power Pav over that from the usual design, due to a raising of the optimal temperature of the evaporator Tevopt to 57O°C). A theoretical laser model proposed in this work correctly described the experimental results obtained in the temperature range 400–600°C for excitation-pulse repetition frequencies ƒ = 10–50 kHz. The conclusions drawn from the model that Pav depends quadratically on ƒ and that Tevopt rises with increasing ƒ were confirmed experimentally.