Vertical cavity surface emitting laser action of an all monolithic ZnO-based microcavity

We report on room temperature laser action of an all monolithic ZnO-based vertical cavity surface emitting laser (VCSEL) under optical pumping. The VCSEL structure consists of a 2{\lambda} microcavity containing 8 ZnO/Zn(0.92)Mg(0.08)O quantum wells embedded in epitaxially grown Zn(0.92)Mg(0.08)O/Zn(0.65)Mg(0.35)O distributed Bragg reflectors (DBRs). As a prerequisite, design and growth of high reflectivity DBRs based on ZnO and (Zn,Mg)O for optical devices operating in the ultraviolet and blue-green spectral range are discussed.Comment: Copyright (2011) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Appl. Phys. Lett. 98, 011101 (2011) and may be found at http://apl.aip.org/resource/1/applab/v98/i1/p011101_s

UV-pumped visible Tb³⁺-lasers

We report on continuous-wave laser operation of T b 3 + : L i L u F 4 under UV pumping. More than five times higher absorption cross sections in the UV allow for shorter gain media, which are required for future high-power diode pumping. The cross-relaxation process is found to efficiently populate the upper laser level 5 D 4 at doping concentrations typically used in T b 3 + -doped gain media. Pumping with a frequency doubled Ti:sapphire laser at 359 nm enables laser operation in the green and yellow spectral range with slope efficiencies of 41% and 20%, respectively, at optical-to-optical efficiencies a factor of two higher than under cyan-blue pumping.</jats:p