Mirrorless Lasing in Optically Pumped Rubidium Vapor
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
Pagination or Media Count:
Mirrorless lasing has been successfully demonstrated in a Rubidium heat pipe. Lasing was observed on the 62Psub 32-62Ssub 12 energy transition at 2.73 microns and on the 62Psub 12-62Ssub 12 transition at 2.79 microns. The transitions were optically pumped from 52Ssub 12-62Psub 32 at 420.2 nm and from 52Ssub 12-62Psub 12 at 421.7 nm, respectively. The 52Ssub 12-62Psub 32 transition was excited over a 36 GHz band, while the 52Ssub 12-62Psub 12 transition was excited over a 24 GHz band. Both pump transitions showed a high degree of saturation and only a small fraction 1 of the incident pump energy was absorbed. Output energies of up to 5 nJ were obtained at 2.73 microns and of up to 5.4 nJ at 2.79 microns when pumped at pulse energies of 4 mJ. Both transitions experienced bleaching at this 4 mJ pump energy, limiting further IR output energy. Increasing rubidium concentration at bleached pump energies showed no increase in laser energy after 170 deg. C, likely due to second order processes. Slope efficiency for both transitions, however, increased linearly with rubidium concentration up to 11 x .000001 The addition of small amounts of argon, helium, and ethane 5-45 Torr were found to fully quench lasing action on both transitions.
- Lasers and Masers