Engineering the kinetics of copper vapor lasers
Abstract
Pulsed copper lasers have a unique capability to produce high average powers at high beam quality (near diffraction-limited) in the visible. Elemental copper vapour lasers (CVLs) have been scaled to very large volumes to give single-device extracted powers of hundreds of watts, but generally this is at the expense of reduced (optimum) repetition rates, lowered efficiencies and lowered specific powers (especially at high beam quality). We recently completed a comprehensive program of experimental and computer modelling studies of CVL discharges, aimed at understanding the complex and interactive processes which determine the power and efficiency of CVLs over a wide range of conditions. Based on these studies we have developed a new technique (called "kinetic enhancement") for power scaling of CVLs using trace gas additives in the laser mixture to moderate key plasma kinetic processes previously limiting performance. Dissociative electron attachment of added hydrogen chloride is used to control interpulse plasma relaxation, and consequently the prepulse electron density, permitting efficient laser excitation to be maintained at elevated metal vapour densities and pulse repetition rate. Output power increases for small-to-medium scale KECVLs of a factor of 3, at wall-plug efficiencies double those of CVLs of similar size, have been demonstrated. Laser power continues to scale to the maximum prf ( ~25kHz) investigated to date, and high-beam-quality performance is greatly improved.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 1998
- Bibcode:
- 1998APS..GEC.NW201P