Suppression of stimulated emission in the phonon wing of a naphthalene crystal with ββ'-dinaphthylethylene impurity by an off-resonance field

An investigation was made of the 4.2°K stimulated emission spectrum of a naphthalene crystal with a high concentration of ββ'-dinaphthylethylene when this crystal was illuminated with off-resonance radiation. The crystal was excited by the third harmonic of a neodymium laser (λ=0.35 μ) and the offresonance radiation was the second harmonic of the same laser (λ=0.53 μ). Simultaneous illumination with the λ=0.35 μ and λ=0.53 μ radiation resulted in a strong reduction in the intensity of stimulated radiation emitted at a frequency in the phonon wing. This effect was attributed to the Raman scattering of the λ=0.53 μ radiation by nonequilibrium phonons.