Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 35: Semiconductor Laser
HL 35.11: Vortrag
Mittwoch, 25. März 2009, 17:00–17:15, BEY 154
Single Mode Quantum Dot Tapered Lasers — •Pia Weinmann1, Bjoern Lekitsch1, Christian Zimmermann2, Emil-Mihai Pavelescu3, Johann-Peter Reithmaier3, Martin Kamp1, and Alfred Forchel1 — 1Technische Physik, Am Hubland, 97074 Würzburg — 2nanoplus GmbH, Oberer Kirschberg 4, 97218 Gerbrunn — 3INA, Universtität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel
A high output power combined with a good beam quality has made tapered lasers promising devices for applications in telecommunication, healthcare or i.e. as pump source for fibre lasers. For several applications, such as frequency doubling or pumping narrow absorption lines, a stable and spectrally narrow emission is required. We present quantum dot (QD) based tapered lasers in the 920nm and 1060nm wavelength range that fulfill these requirements. Compared to quantum well material, the shift of the emission wavelength with temperature is reduced by a factor of more than two since the decrease of the bandgap with increasing temperature can be partially balanced by the blueshift of the QD peak gain due to the increasing losses. Further stabilization of the wavelength can be achieved by including a wavelength selective distributed Bragg reflector (DBR) in the laser cavity. We have combined gain and index guided tapered lasers with etched DBR gratings, this approach allows an overgrowth free fabrication. The emission spectrum of the devices shows a very narrow spectral linewidth in combination with sidemode suppression ratios of over 40 dB. The shift of the emission wavelength with temperature is only 0.07nm/K. Output powers up to 2W are achieved with good beam quality.