Fine structure in the stimulated emission spectra of organic dye solutions

A study was made of the stimulated emission from liquid and solid solutions of 2, 5-diphenyloxazole. These solutions were characterized by electronic spectra with a vibrational structure and they were excited by the second harmonic of ruby laser radiation which not only produced coherent radiation but also caused resonant stimulated Raman scattering (RSRS) of light in the ultraviolet part of the spectrum at 160–293°K. Two RSRS lines were observed at 1543 and 1606 cm^–1. The line intensities increased with rising temperature. The line positions were independent of the nature of the solvent, concentration of the solution, temperature, and Q factor of the resonator; only the relative intensities of the lines were affected by these factors.