Characteristics of stimulated emission from CdS by electron-beam pumping

The results of electron-beam experiments on undoped single-crystal CdS are presented. A description of the beam-injection apparatus is given. The relevance of various indications for lasing in this type of structure is discussed, and an operational definition of lasing threshold current is described. In this paper intensity versus pumping carves, stimulated-emission moding curves, and measurements of the frequency- and time-dependent characteristics of the stimulated emission from undoped CdS will be presented and discussed. New data show that there is a 1.1 Å/ns shift of the stimulated peak emission to longer wavelengths which is independent of the pumping current density. This effect is not understood but is crucial to the understanding of the CdS electron-beam-pumped semiconductor laser.