Cs 894.3 nm laser pumped by photoassociation of Cs-Kr pairs: excitation of the Cs D2 blue and red satellites

摘要

Lasing on the D 1 transition ( 6 P 1 ∕ 2 2 → 6 S 1 ∕ 2 2 ) of Cs has been observed by photoassociating Cs–Kr atomic pairs with a tunable, pulsed dye laser. Pumping of the blue or red satellites of the Cs D 2 line ( 6 P 3 ∕ 2 2 ⇆ 6 S 1 ∕ 2 2 ) , peaking at ∼ 841.1   nm and ∼ 853   nm (respectively) in Cs ∕ Kr ∕ C 2 H 6 gas mixtures, provides a photodissociation laser in which the CsKr excimer parent molecule is not, at any point in the pumping process, in a bound electronic state. Relative to the absorbed pump pulse energy, laser slope efficiencies ≳ 5 % have been measured when the Cs number density is in the range of 5 × 10 14 – 1.5 × 10 15   cm − 3 and the pump wavelength is 841.1   nm . Direct photoexcitation of the Cs 6 P 3 ∕ 2 2 state at 852.1   nm under these conditions is a less efficient pathway for pumping the 894.3   nm laser, presumably as a result of competing nonlinear optical processes such as 1 + 2 resonantly enhanced multiphoton ionization of the alkali atom.