In-situ etching of patterned GaAs/InGaP surfaces for highly efficient 975 nm DFB-BA diode lasers

摘要

In-situ etching with CBr_4 has been used to form buried Bragg gratings in AlGaAs-based broad area diode lasers with distributed feedback (DFB-BA) by pattern transfer into In_(0.49)Ga_(0.51)P within the MOVPE reactor. STEM/EDXS measurements show that the Bragg grating is finally formed by 10 nm thick In_(0.49)Ga_(0.51)P stripes that are fully embedded in Al_xGa_(1_x)As. The oxygen sheet concentration at the regrowth interface is found by SIMS to be below 1 × 10~(16) cm~(~2). DFB-BA lasers fabricated using in-situ etching of the grating reach optical output power > 12 W and peak wall-plug efficiencies > 60%.