8 W continuous wave front-facet power from broad-waveguide Al-free 980 nm diode lasers

Abstract

Al-free 980 nm InGaAs/InGaAsP/InGaP laser structures grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) have been optimized for high cw output power by incorporating a broad waveguide design. Increasing the optical-confinement layer total thickness from 0.2 to 1.0 μm decreases the internal loss fivefold to 1.0–1.5 cm−1, and doubles the transverse spot size to 0.6 μm (full width half-maximum). Consequently, 4-mm long, 100-μm-aperture devices emit up to 8.1 W front-facet cw power. cw power conversion efficiencies as high as 59% are obtained from 0.5-mm long devices. Catastrophic-optical-mirror-damage (COMD) power-density levels reach 15.0–15.5 MW/cm2, and are found similar to those for InGaAs/AlGaAs facet-coated diode lasers.