Thin-film lasers

The article reviews experimental and theoretical research findings on thin-film electroluminescent (EL) structures incorporating a Fabry-Perot resonator, and examines the outlook for successful design of a thin-film EL laser. Attention is centered on Mn-doped ZnS thin film materials, impact excitation of EL, and distributed feedback (DFB) phenomena in organic thin films. Population inversion via impact excitation of impurity centers and the effect of variation of dopant concentration are studied, radiation patterns of ZnS:Mn thin film resonator cells are displayed, and advantages of a proposed new solid-state EL laser based on impact excitation are explored. Room-temperature lasing with CW excitation, high quantum yield, compact size, and large radiated surface area are envisaged.