Abstract: An improved method of manufacturing holographic elements for solar concentrator, which is a necessity for the future of viable low cost solar power. Utilizing extremely high relative humidity levels during the fabrication of holographic plates, exposing the holographic plate to electromagnetic radiation at particular humidity levels, and having a relative angle between recording beams during exposure makes it possible to fabricate high efficiency holographic elements that diffract over a broad bandwidth. These high efficiency, broad bandwidth holographic elements are most effective in certain solar concentrating systems.