Novel multiplexed volume holographic optical elements for the development of highly multiplexed photonic interconnection and holographic memory systems with maximum optical throughput efficiency and minimum crosstalk, based on parallel incoherent/coherent double angularly multiplexed volume holographic...http://www.google.ca/patents/US5661577?utm_source=gb-gplus-sharePatent US5661577 - Incoherent/coherent double angularly multiplexed volume holographic optical elements
