Multi-wavelength light-emitting semiconductor devices

A multi-wavelength light-emitting (MWLE) semiconductor device such as a vertical cavity surface emitting laser (VCSEL) array includes a substrate 104, a first reflector 106 on the substrate, a light emission layer 107 on the first reflector, second reflectors 114A, 114B, 114C on corresponding active regions; and apertures 110A, 110B, 110C on corresponding active regions. The light emission layer 107 includes discrete active regions 108A, 108B, 108C having primary emission wavelengths different from each other. The primary emission wavelengths may range between about 1100 nm and about 1700nm, and are tuned by selective processing e.g. annealing of active regions 108A, 108B & 108C. The devices have applications in 3D sensing systems such as facial recognition systems and in optical communications. The light emission layer may include III-V compounds such as GaAsN, InGaAsN or AlGaSbPN, with p-type or n-type doping, including a nitrogen atom concentration between 0% and 5%, allowing a smaller energy bandgap compared to either a higher concentration of nitrogen or no nitrogen. Grating structures (Fig. 3: 322A, 322B, 322C) may be used to tune the primary emission wavelengths emitted through the second reflectors. Tunnel junction structures (Fig. 5: 523A, 523B) may act as ohmic contacts within VCSELs (Fig. 5: 502A-502C) allowing the conductivity type of first reflector or second reflectors to be reversed.