650 nm tapered lasers with 1 W maximum output power and nearly diffraction limited beam quality at 500 mW

Published in:
High-Power Diode Laser Technology and Applications VI, edited by Mark S. Zediker, Proc. of SPIE Vol. 6876, 68760M, (2008).
© SPIE 2008. 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 SPIE.

Abstract:
High-brightness 650 nm tapered lasers with output powers up to 1 W and nearly diffraction limited beam quality at 500 mW were realized. The vertical structure is based on an InGaP single quantum well (SQW) embedded in AlGaInP waveguide layers and n-AlInP and p-AlGaAs cladding layers. The tapered structure consists of a 750 µm long ridge waveguide section and a 1.25 mm long flared section. Taper angles of 2°, 3° and 4° were manufactured. At 15°C, the devices achieve 1 W at an operating current below 2 A in CW operation. The conversion efficiency is about 20%. At 500 mW output power a nearly diffraction limited beam quality with a beam propagation ratio of about 1.5 was measured.
The reliability was studied in a long-term test for five tapered diodes at 250 mW over 1,000 h and than at 500 mW over 2,000 h. All diodes survived this test. The beam quality remains nearly stable over the complete reliability test.

Keywords:
red lasers, tapered lasers, high power diode lasers, reliability, diffraction limited

Full version in pdf-format.