Electrically-pumped (Ga,In,Al)N vertical-cavity surface-emitting laser

A method for independently controlling the optical mode and current distribution in a vertical-cavity surface-emitting laser (VCSEL) to optimize modal gain, comprising the steps of:

• (a) providing at least one curved mirror fabricated onto a substrate of the VCSEL;
• and
• (b) providing at least one electrical aperture formed by patterning one or more thin dielectric layers and then depositing one or more low-loss thin metal layers on and around the one or more thin dielectric layers,
• (c) wherein the low-loss thin metal layers simultaneously provide low resistance, non-rectifying, ohmic electrical contact, and enhanced lateral current spreading to the VCSEL.

A method of fabricating a vertical-cavity surface-emitting laser (VCSEL), comprising:

• (a) selecting a substrate;
• (b) depositing a template layer on the substrate;
• (c) depositing one or more first cladding layers on the substrate or template layer;
• (d) depositing an active region on top of the first cladding layers and at a position of maximum intensity of an optical standing wave pattern of the VCSEL;
• (e) depositing one or more second cladding layers on top of the active region;
• (f) selecting a micromirror radius of curvature to achieve a desired optical mode pattern inside a VCSEL cavity,
• (g) forming a micromirror with the radius of curvature in the substrate;
• (h) etching a mesa in the first cladding layers and active layer in order to define a volume that comprises a VCSEL pillar and at least one low-loss thin metal layer;
• (i) depositing an aperture layer on top of the cladding layers;
• (j) depositing at least one low-loss thin metal layer at or near a standing wave null of a VCSEL optical cavity mode to enhance current spreading and provide low resistance and non-rectifying ohmic contact to the VCSEL;
• (k) depositing one or more metal contact pads, comprising an n-contact, on top of the low-loss thin metal layer for providing electrical contact to the VCSEL;
• (l) depositing a dielectric distributed Bragg reflector (DBR), metallic mirror, or combined metallic/dielectric DBR mirror on top of the low-loss thin metal to form a top reflector for a VCSEL cavity;
• and
• (m) depositing an epitaxial or dielectric DBR, metallic mirror, or combined metallic/dielectric DBR mirror on a surface of the micromirror to form a bottom reflector for the VCSEL cavity.