Multiplexing volume holographic gratings for a spectral-spatial imaging system

Multiplexed gratings can be used in an imaging system to project depth sections of a tested object onto different surface locations of a camera. This technique is based on volume holographic Bragg filters used in conjunction with conventional optical imaging components to form a volume holographic imaging system (VHIS). Due to the high angular selectivity and high wavelength selectivity of the system, the VHIS can be used to provide spectral-spatial information of the object that is being observed, and eliminate the need for mechanical scanning. Multiple sections of the object can be viewed by using angle multiplexed holographic elements formed in a volume holographic material. To achieve the highly selective characteristic of a holographic filter, 2mm thick samples of phenanthrenequinone-doped methyl methacrylate (PQ-PMMA) is used as the holographic recording materials. Rigorous coupled wave models are used to theoretically predict the performance of the gratings. Results from both modeling and experiments are presented.