The threshold pump energies at 1.06 µm and Raman gain coefficients of stimulated Raman scattering (SRS) at 1.54 µm have been measured in both single-pass and half-resonator configurations at various methane pressures. In the single-pass configuration, the Raman gain coefficients of the backward and forward SRS are 0.32 and 0.23 cm/GW at 95 atm, respectively. The backward Raman gain coefficient is higher than the forward Raman gain coefficient. This gain reduction is caused by the depletion of local pump intensity, the phase-matching conditions, and the transient effect of the high amplification rate in the forward SRS process. In the half-resonator configuration, the Raman gain coefficient was 0.46 cm/GW at 75 atm of methane.
© 2001 Optical Society of America
Original Manuscript: November 18, 1999
Revised Manuscript: June 22, 2000
Published: April 20, 2001
Young Soo Choi, "Asymmetry of the forward and backward Raman gain coefficient at 1.54 µm in methane," Appl. Opt. 40, 1925-1930 (2001)