Improvement in Light Output of Thin-Film Vertical-Cavity Surface-Emitting Lasers Transferred onto A1N Substrates

Thin-film 850-nm vertical-cavity surface-emitting lasers (VCSELs) were improved in light output power by designing both the reflectivity of the distributed Bragg reflector on the light-emitting side and also the degree of de-tuning between the photoluminescence peak and the etalon wavelength. Thin-film VCSELs, which were fabricated on A1N substrates by a functional layer transfer technique, are attractive components for the hybrid integration of optoelectronic devices. Their maximum output power was 2.8 mW and their slope efficiency was 0.40 W/A for the 15μm diameter VCSEL devices that we studied. Uniform spontaneous emission over the entire mesa area, and a single transverse laser mode up to 1.3 times the threshold current were confirmed by observing the near-field images.