Vertical Cavity Surface-Emitting Laser (VCSEL) pumps for Reduced Eye Hazard Wavelength High Energy Fiber Lasers

This SBIR proposal is to develop a new high power VCSEL array that can achieve higher efficiency and higher brightness than existing technology, suitable for pumping eye-safe fiber lasers. The technology uses a lithographically defined VCSEL process to achieve dense integration and reduce the diode electrical resistance and optical loss to increase efficiency. The array technology is designed to reach high power and high power density, and can provide advantages in heat sinking for active cooling. Thermal resistance is decreased over existing technology by eliminating buried oxide layers, and brightness is increased through dense packing and special cavity designs. Initial demonstrations are for a 980 nm high efficiency pump diode for Er-doped fiber lasers. The new array technology could offer advantages over current edge-emitter technology used for high power bars and stacks by providing increased reliability at a reduced cost for both the diode and packaging. With optimized designs, the power conversion efficiency, power density, and brightness could reach or exceed that of high power edge-emitters.