Using a sodium Raman laser that is pumped by a single-frequency cw dye laser, we have measured the narrowband Raman gain that exists in the vicinity of the sodium D1 line. Large gains (>10 cm−1) are measured at moderate pump intensities and sodium densities. The high gain allows us to detect directly a 1.772-GHz beat on the pump beam after it makes only a single pass through the sodium cell. By scanning the frequency of the sodium Raman laser while keeping the pump intensity and frequency constant, we are able to map out the Raman gain profile. The narrowness of the Raman gain is consistent with the narrow beat signal between the Raman-laser beam and the pump beam that was reported earlier [Opt. Lett. 16, 1853 (1991)].
© 1992 Optical Society of America
Original Manuscript: September 23, 1991
Published: March 15, 1992
Matthew Poelker and Prem Kumar, "Sodium Raman laser: direct measurements of the narrow-band Raman gain," Opt. Lett. 17, 399-401 (1992)