Wavelength multiplexed volume holographic optical couplers to couple red, green, and blue light for solar collection

The proposed wavelength multiplexed, volume holographic optical coupler uses total internal reflection to guide incident light of a wavelength from 317nm to 700nm. The diffractive elements are recorded with 457nm (transmission holographic recording) and 532nm (reflection holographic recording) lasers in Bayfol HX 200TM photopolymer. The novelty of the device is the particular combination of diffractive optical elements designed so that they can be holographically recorded with two different wavelengths without the need for prisms to facilitate the propagation of the recording beam in the recording layer at angles exceeding the internal critical angle. and will couple three primary colours (Blue, Green, and Red) of the visible spectrum in a single device for non-normal incidence angles. Multiwavelength characterisations have been carried out to support the application of such couplers in the solar collection.