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

摘要

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℃, 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.