He - Sr Recombination laser with helium pressure up to 5 ATM

• Published in: Journal of Russian laser research Vol. 15; no. 1; pp. 66 - 68
• Main Authors: Atamas’, S. N., Latush, E. L., Sèm, M. F.
• Format: Journal Article
• Language: English
• Published: United States 01.01.1994
• Subjects: 426002 - Engineering- Lasers & Masers- (1990-); ALKALINE EARTH METALS; BINARY MIXTURES; DISPERSIONS; ELEMENTS; ENGINEERING; FLUIDS; GAS LASERS; GASES; HELIUM; LASERS; METALS; MIXTURES; NONMETALS; POWER; PRESSURE DEPENDENCE; RARE GASES; RECOMBINATION; STRONTIUM
• ISSN: 1071-2836; 1573-8760
• DOI: 10.1007/BF02581048

The He-Sr recombination laser is an effective source of coherent radiation in the violet (430.5 nm). A self-heating longitudinal laser with an active-medium volume [approximately] 100 cm[sup 3] and a helium pressure [approximately] 500 torr usually delivers an average lasing power at a [approximately] 1-W level, an efficiency [approximately] 0.1%, and a pulse repetition frequency 4-6 kHz. With forced water cooling of the active part of the discharge the power reached 3.9 W from a tube 1.1 cm in diameter and 33 cm long, by raising the pulse repetition frequency to 29 kHz. The need for high buffer-gas pressures is determined by the recombination mechanism of the laser-transition pumping: elastic collisions of the electrons with the helium and atoms and ions in the afterglow of the discharge cool the electron gas, contributing to an ever more effective recombination process and consequently to a rise of the pump level. The present paper attempts to determine the helium pressure at which the output power and the lasing-pulse energy of an He-Sr laser begin to sag.