THRESHOLD OF STIMULATED-EMISSION IN MULTIVALLEY LEAD SALTS

A study of the threshold of stimulated emission for optically pumped P bSe and PbTe is presented, The influence of external parameters such a s magnetic field and misfit strain on the threshold as well as the dif ferential quantum efficiency of stimulated emission are analyzed. It i s shown that effective energy gap shifts caused by the external parame ters only weakly influence the threshold, whereas the main effect aris es from the redistribution of the carriers in the multivalley band str ucture when the degeneracy of the carriers in the valleys at the L poi nts of the Brillouin zone is lifted. A consistent qualitative theoreti cal explanation for the effects is given. (C) 1995 American Institute of Physics.