Diode Pumped Cesium Laser

Review of alkali laser research and development

“…30 We used a narrowband diode laser operating at 852 nm (SDL-8630, linewidth is less than 1 MHz) and a 5-cm-long Cs vapor cell with 100 torr of ethane buffer gas. The gain medium was longitudinally pumped through the one of the cavity mirrors.…”

“…The first really efficient lasing in pulsed and continuous wave (CW) operation in Rb and Cs vapors was observed in 2003 to 2005, 28,29 using a Ti:sapphire laser for optical pumping. The first diode pumped alkali laser (based on Cs vapor) was demonstrated in 2005, 30 and the first optically pumped Potassium laser was realized in 2007. 31 After these first demonstrations of efficient alkali lasers operation, several research groups in the United States and abroad started extensive experimental and theoretical studies of all aspects of diode pumped alkali laser (DPAL) operation such as collisional processes, line broadening, DPAL modeling, etc.…”

Developments toward a reliable diode-pumped hydrocarbon-free 795-nm Rubidium laser

“…In 2002 researchers at Lawrence Livermore National Laboratory demonstrated a new class of laser, combining features from both the gas and solid state laser families, based on diode excitation of atomic alkali vapors [1]. Since that first demonstration of a rubidium resonance transition laser, multiple demonstrations of alkali resonance transition lasers have been reported in the scientific literature using Rb [2], Cs [3,4,5,6] and K [7] as the gain media. These systems are pumped on the alkali D 2 (n 2 S 1/2 →n 2 P 3/2 ) transition and lased on the D 1 (n 2 P 1/2 →n 2 S 1/2 ) transition.…”

“…The advantage of using isotopically enriched 3 He stems from its lower mass and therefore higher thermal velocity at a given temperature in comparison with naturally occurring He. The higher thermal velocity associated with 3 He increases the F-S mixing rate, 4 He by approximately 4/3 1.15 ≈ , which not only benefits the F-S mixing rate which depends directly on v r , but also improves thermal management in the cell. Since the thermal conductivity κ of a gas to lowest order is proportional to the mean particle velocity, κ of 3 He is larger than that of 4 He by the same factor.…”

“…The higher thermal velocity associated with 3 He increases the F-S mixing rate, 4 He by approximately 4/3 1.15 ≈ , which not only benefits the F-S mixing rate which depends directly on v r , but also improves thermal management in the cell. Since the thermal conductivity κ of a gas to lowest order is proportional to the mean particle velocity, κ of 3 He is larger than that of 4 He by the same factor. Secondly, the F-S mixing cross section itself has a velocity dependence that is expected to give a Rb- 3 He value larger than the Rb- 4 He value at a given cell temperature due to the difference in thermal speeds of the two He isotopes [10].…”