Laser induced molecular dissociation and ionization of potassium vapour

Abstract

We report a single photon molecular dissociation of potassium vapour, K 2 → h ̷ ω K(4s 2S 1/2)+ K ∗(4 p) 2 P 1/2,3/2 and subsequent excitation and ionization using a Nd:YAG pumped dye laser in conjunction with a thermionic diode detector. The even parity n s 2 S 1 2 and n d 2 D 3 2 , 5 2 Rydberg series resulting from the absorption of another photon from the same laser pulse by the excited ( 4 p 2 P 1 2 , 3 2 ) atomic potassium have been detected over the wavelength range 494 to 456 nm. Using this excitation and ionization technique, high Rydberg levels excited from both the 4p fine structure components: 4 p 2 P 1 2 → n d 2 D 3 2 (10 ≤ n ≤ 24) and n s 2 S 1 2 (10 ≤ n ≤ 26), 4 p 2 P 3 2 → n d 2 D 3 2 , 5 2 (8 ≤ n ≤ 33) and n s 2 S 1 2 (10 ≤ n ≤ 29) are observed for the first time. The relative intensities of the Rydberg series attached to these fine structure components demonstrate that the potassium dimer dissociates predominantly to the 4 p 2 P 3 2 level of the potassium atom.