Effect of buffer gas on the generation of eye-safe 1.54 μm radiation using the stimulated Raman scattering technique in CH4
✍ Scribed by K. Sentrayan; A. Michael; U.N. Singh; V.S. Kushawaha
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 618 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0030-3992
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✦ Synopsis
Experimental results on the generation of 1.54 pm eye-safe radiation in pure CH4, CH4:He and CH4:Ar mixtures pumped by the fundamental of an Nd:YAG laser, using the stimulated Raman scattering (SRS) technique, are described. A decrease in the energy conversion efficiency and degradation in the beam quality of S1 was observed in pure CH4 at high pump energies. This problem was overcome in CH4: He and CH4:Ar mixtures. Compared with the first Stokes (1.54pm) energy conversion efficiency in pure CH4, at a pump energy of 126 mJ, an enhancement of 50% in energy conversion efficiency was observed in the CH4:Ar mixture (60% argon concentration) and as much as 100% in the CH4: He mixture (60% helium concentration).
The use of these buffer gas mixtures improved the spatial beam quality of the Stokes radiation considerably and also resulted in raising the pump threshold for optical breakdown of the Raman gain medium. 01997 Elsevier Science Ltd.