Measurement of Raman gain coefficients of hydrogen, deuterium, and methane

The authors report measurements of the absolute Raman gain of H/sub 2/ Q(1), D/sub 2/ Q(2), and CH/sub 4/ ( nu /sub 1/) at 532 nm using a Raman oscillator/amplifier arrangement. Experimentally determined steady-state gain coefficients are compared to values calculated using spectroscopic data. The dependence of the observed gain on the pressure mismatch in a Raman oscillator/amplifier system is also investigated. The measured values for hydrogen and methane are found to agree with calculated values and with the results of previous measurements. For deuterium the authors find a value of 0.45 cm/GW, which also agrees reasonably well with the calculated value.>