Phenantrenequinone doped poly(methyl-methacrylate) (PQ:PMMA) is a holographic substrate that can be used for angle or wavelength multiplexed Bragg gratings. However, efficient writings can be done only using a high-power, long-coherence volume laser over a limited wavelength range. This constraint makes it difficult to write gratings that would diffract several different read wavelengths into a single direction. We describe the rules for writing such gratings, taking into account the differences in the mean index seen by the write and read wavelengths. We further demonstrate the use of such a transmission hologram for wavelength-division multiplexing in a free-space optical communication system.

We demonstrate the use of angle multiplexed holograms for wavelength division multiplexing in free space optical communications, with application to absorption based monocular passive ranging using three simultaneous and superimposed spectral filters.

We demonstrate PQ:PMMA transmission holograms for free space wavelength division multiplexing around 1550 nm, which can be used in free-space communication systems that require eye-safe lasers. The wavelength can be customized during fabrication.