Diffractive Optical Elements for Efficient Laser Cavities

ABSTRACT:The objective of this proposal is to develop and demonstrate an innovative laser cavity design based on high efficiency diffractive optical elements (DOEs) to replace currently used external bulk laser optics. This innovation will improve the stability of Vertical External Cavity Surface Emitting Laser (VECSEL) systems as well as other types of solid state laser systems. The developed DOEs for efficient laser cavities will be designed to improve the operational characteristics, resulting in improved stability and robustness, as well as reducing the size, weight, and power (SWaP) of VECSELs. The VECSELs will be capable of generating a variety of wavelength from visible through infrared by incorporating innovative DOEs as part of the laser cavities. The DOEs may be bonded directly to the semiconductor structure of VECSELs to improve the robustness and significantly reduce the size and weight of the package. The DOEs can also be directly fabricated as surface relief micro-structures onto the outer layer of the VECSEL semiconductor material employing well-established lithographic techniques. This approach further improves the VECSELs manufacturability, as well as increases the registration accuracy of the laser cavity mirrors with respect to the laser gain medium, eliminating costly and sensitive active alignment processes during VECSEL production.BENEFIT:1. Improved stability and operational robustness of Vertical External Cavity Surface Emitting Laser (VECSEL) systems as well as other types of solid state lasers. 2. Significantly reduced size, weight, and power (SWAP) of VECSEL systems. 3. Improved VECSELs manufacturability by increasing the registration accuracy of laser cavity mirrors and the pump radiation with respect to the laser gain medium, eliminating costly and sensitive active alignment processes during VECSEL production.