High-power broad-area InGaNAs/GaAs quantum-well lasers in the 1200 nm range

High-power broad-area InGaNAs/GaAs quantum-well (QW) edge-emitting lasers on GaAs substrates in the 1200 nm range are reported. The epitaxial layers of the InGaNAs/GaAs QW laser wafers were grown on n⁺-GaAs substrates by using metal-organic chemical vapor deposition (MOCVD). The thickness of the InGaNAs/GaAs QW layers is 70 Å/1200 Å. The indium content (x) of the In_xGa_1−xN_yAs_1−y QW layers is estimated to be 0.35-0.36, while the nitrogen content (y) is estimated to be 0.006-0.009. More indium content (In) and nitrogen content (N) in the InGaNAs QW layer enables the laser emission up to 1300 nm range. The epitaxial layer quality, however, is limited by the strain in the grown layer. The devices were made with different ridge widths from 5 to 50 μm. A very low threshold current density (J_th) of 80 A/cm² has been obtained for the 50 μm × 500 μm LD. A number of InGaNAs/GaAs epi-wafers were made into broad-area LDs. A maximum output power of 95 mW was measured for the broad-area InGaNAs/GaAs QW LDs. The variations in the output powers of the broad-area LDs are mainly due to strain-induced defects the InGaNAs QW layers.