Review of recent advances in photosensitive polymer materials and requirements for transmission diffractive optical elements for LED light sources

Scattered light from outdoor LED sources is a major contributor to blue-spectrum light pollution which negatively impacts ecology and public health. Volume holographic diffractive optical elements (DOEs), made with low-cost photosensitive polymers, are proposed as a technological solution that can minimise this scattering. This review examines requirements needed for efficient operation of transmission-format DOEs with LEDs and implications for material choices. For such DOEs to have a single diffraction order and high efficiency there is a corresponding range of acceptable ∆n. A survey of materials also found that many current materials satisfy the ∆n requirements for single-element DOEs. It is proposed that future efforts focus on robustness, environmental sustainability, scalability, multiplexing, optical quality, and reduced cost.