Berlin 2008 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 7: Semiconductor Nanophotonics: Materials, Models, Devices - Surface Emitters

DS 7.4: Hauptvortrag

Montag, 25. Februar 2008, 12:30–13:00, H 2032

Recent Advances on Long Wavelength VCSELs (> 1300 nm) — •Markus C. Amann — Walter Schottky Institut, Technische Universität München, D-85748 Garching, Germany

Recently, InP-based long-wavelength vertical-cavity surface-emitting lasers (VCSELs) based on buried tunnel junctions (BTJ VCSEL) achieved excellent performance for the entire 1300-2300nm wavelength range. With this device concept, a low-resistive tunnel junction enables the replacement of the major part of the p-doped layers by n-doped ones yielding ultra-low electrical resistances and reduced optical losses as well as a self-adjusted transverse photon and carrier confinement. This concept also allows the application of hybrid Au-dielectric Bragg mirrors with high index contrast and reflectivity. BTJ-VCSEL show sub-mA threshold currents, 0.9V threshold voltage (at 1550 nm), operation voltages below 1.2V, 30-70 ohm series resistance, differential efficiencies >25%, up to 3mW single-mode optical output power, >110°C cw operation, stable polarization and single-mode operation with SMSR of the order 50 dB. Electro-thermal wavelength-tuning over 4nm and micromechanical tuning over more than 40nm both in the continuous tuning-mode and with SMSR >30dB can be accomplished. Besides the device design and technology, we will discuss recent achievements on high-speed VCSELs and BTJ-VCSEL arrays and demonstrate experiments on broadband communications and spectroscopic trace-gas sensing.