Abstract
A high-efficiency microchip violet-green laser converter based on a molecular-beam epitaxy grown green-emitting (Zn) CdSe quantum dot (QD) II-VI laser heterostructure, optically pumped by emission of a cheap violet InGaN laser diode (LD) was demonstrated. The active region of the II-VI laser heterostructure consisted of three electronically coupled (Zn) CdSe QD sheets in a single ZnSe quantum well (QW) placed asymmetrically inside a graded-index ZnMgSSe/ZnSe superlattice optical waveguide. The cavity length of the cleaved-facet II-VI laser was 130 mu m which is a nearly optimal value for minimizing the excitation power. InGaN LD radiation was focused into a narrow stripe on the surface of the II-VI laser by a microlens optical system. The converter showed laser emission at 541 nm with threshold excitation power of similar to 0.5W. The maximal output pulse power and conversion efficiency of 1.5W and similar to 15%, respectively, were achieved. The device was mounted in a standard TO-18 LD package. Photograph of the operating violet-green microchip laser converter. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim