Wavefront conversion by 90-degree geometry volume holograms between plane and spherical waves

摘要

The volume holograms recorded by use of 90-degree geometry with reference and signal beams entering orthogonal crystal faces, have been widely used in fields such as waveguide couplers, holographic lenses, high-density holographic data storage. They posses the peculiar advantageous of small volume, ease of integrating and cascading. In fabrication of volume holograms are capable of converting various wavefronts into each other with high efficiency. But most of the researches were based on on-axis holographic optical elements such as cylindrical lens or spherical lens but not 90-degree geometry. In this paper, we investigate the properties of holographic lenses capable of converting plane waves into spherical waves in a perpendicular direction. Our research submits an analytical integral solution for the wavefront conversion problem in 90-degree geometry. The results can be of great practical importance in the design of volume holographic optical elements.