Abstract

Stimulated Raman scattering of H₂ + CH₄ mixture was investigated using frequency doubling of Nd³⁺:YAG lasers (532 nm) as a pumping source. A Raman cell, 1000 mm long, 15-mm diameter, was first filled with 10-atm H₂ then CH₄ was gradually pressed into the cell. As the CH₄ increased, it was observed that the intensity of the first-order Stokes line of H₂ became weaker and that of the first-order anti-Stokes line became stronger. Then, as the intensity of both S₁ and AS₁ weakened and the profiles of the lines broadened, suppression and coupling between H₂ and CH₄ appeared. The frequencies of S₁ and AS₁ [obtained by an optical spectrum analyzer (OSA) WP-4] shifted with changing CH₄ pressure. A preliminary explanation of the mechanism of the frequency shift is given.

© 1986 Optical Society of America