High-Resolution Laser Spectroscopy of Aluminium, Gallium and Thallium

Abstract

Applying the techniques of resonant and off-resonant Doppler-free 2-photon laser spectroscopy, we have studied a number of transitions in the group IIIa elements Al, Ga and Tl with the thermionic diode. In order to check the accuracy of the experimental set-up and the spectroscopic method applied, the hfs of the intermediate state 3d 2D3/2,5/2 of 27Al has been determined from the spectra of the 3p 2PJ-3d 2DJ-nf 2FJ or -np 2PJ transitions and compared with more precise values by other authors from atomic beam magnetic resonance measurements. From 4p 2P1/2-nf 2FJ and 4p 2PJ-4d 2DJ-nf 2FJ or -np 2PJ transitions in 69,71Ga, we have deduced the hfs and the residual isotope shifts (RLIS) of the intermediate states (4d 2D3/2,5/2) and the RLIS of the 4p 2P1/2,3/2 ground states. In Tl, we have measured the 6p 2P1/2-nf2F5/2 (n = 6-9) and -10p 2P3/2 lines. From the experimental results we have determined the residual level isotope shift (205,203Tl) of the 6p 2P1/2 state and the hfs of the 10p 2P3/2 level.