B. Sumpf^a, G. Erbert^a, J. Fricke^a, P. Froese^a, R. Häring^b, W.G. Kaenders^b, A. Klehr^a, F. Lison^b, P. Ressel^a, H. Wenzel^a, M. Weyers^a, M. Zorn^a, G. Tränkle^a

Published in:

Proc. SPIE, vol. 6485, no. 648517 (2007).

Abstract:

High-brightness tapered lasers and amplifiers at 670 nm with output powers up to 1 W and nearly diffraction limited beam quality were realised. The devices consist of a 750 µm long straight section and a 1250 µm long tapered section. Devices with a taper angle of 2°, 3° and 4° were manufactured. The material quality was studied in a long-term test for ridge-waveguide lasers. Devices with 7.5 µm ridge width show reliable operation at 100 mW output power over more than 10000 h. At a temperature of 15°C a tapered lasers with an angle of 4° reached an output power of 1 W at a current of 2.1 A. The highest conversion efficiency for this device was 24%, the peak wavelength of the emission was 668 nm and the spectral width was smaller than 0.2 nm. The beam propagation factor was M² = 1.7 (1/e²) and M² = 3.0 (second moments).
At 500 mW output power, master-oscillator power-amplifier (MOPA) devices showed also a nearly diffraction limited beam quality with M² < 1.5 and reliable operation with degradation rates as low as 7x10^-6 h^-1 over 1200 h. The spectral line-width in this arrangement is determined by the master oscillator and is suitable for high-resolution spectroscopy.

Keywords:

red lasers, tapered lasers, tapered amplifiers, MOPA, high power diode lasers, diffraction limited

© 1994-2007 SPIE - The International Society for Optical Engineering. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the American Institute of Physics.

Full version in pdf-format.