Uniform wafer-bonded oxide-confined bottom-emitting 850-nm VCSEL arrays on sapphire substrates

• Published in: IEEE photonics technology letters Vol. 13; no. 4; pp. 263 - 265
• Main Authors: Chao-Kun Lin, Dapkus, P.D.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2001; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Apertures; Arrays; Gallium arsenide; Gallium arsenides; Optical arrays; Particle scattering; Power generation; Quantum efficiency; Sapphire; Substrates; Surface emitting lasers; Threshold current; Threshold currents; Vertical cavity surface emission lasers; Vertical cavity surface emitting lasers; Wafer bonding
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/68.917819

Uniform bottom-emitting 850-nm vertical-cavity surface-emitting laser (VCSEL) arrays on sapphire substrates have been demonstrated using wafer bonding technology to transfer the epitaxially-grown VCSEL structures from GaAs substrates onto sapphire substrates. The uniformity of the VCSEL arrays were improved by placing thin oxide aperture at the standing wave node to reduce scattering loss for small aperture devices. The averaged threshold current of a 5×5 VCSEL array is as low as 346 μA, while the averaged external quantum efficiency approaches 57%. The maximum wall-plug efficiency is 25% and the single-mode output power is more than 2 mW under continuous-wave current excitation at room temperature. We have also demonstrated a large (10×20) VCSEL array with variations of threshold current and external quantum efficiency less than 4% and 2%, respectively.