Laser spectroscopy of some HgCd spin-orbit states.

Abstract

Fluorescence and excitation spectra arising from transitions between excited states of the HgCd exciplex molecule were produced in a mixture of Hg and Cd vapors following pump-and-probe laser excitation. The vapor mixture, contained in a sealed quartz cell, was irradiated by pulsed pump (3261 \AA{}) and probe (4300\char21{}4750 \AA{}) laser beams, delayed by 450 ns relative to one another. The fluorescence bands were recorded with a monochromator, a photomultiplier, and a digitizing oscilloscope controlled by a microcomputer. In addition to the previously reported and analyzed ``blue-band'' fluorescence that can be excited with a single laser, we observed short-lived and structured fluorescence bands as well as the corresponding excitation bands in the blue spectral region, which we assigned to transitions between specific states of HgCd. An analysis of the bands yielded the vibrational constants for some of the states, as well as their relative internuclear equilibrium separations. These results provide an initial basis for the draft of a partial potential-energy diagram consisting of spin-orbit states correlated to the 5 $^{3}$P manifold in Cd.