Abstract

The energy-related holographic applications such as spectrum-splitting holoconcentrators,¹ solar-control Lippmann holowindows,² heliostat dichroic/polychroic non-Snellian mirrors,³ etc. have unique potential of realizing wavelength/angular selective spatial processing operations. Therefore, the systems with properties such as spectrum-selective Snellian/non-Snellian reflection, deflection concentration, and collimation can be produced by using large-size (1-m² area), flat or curved thin holographic coatings. In this paper it was shown that only superhigh-efficiency (SHE) holographic technology, based on Bragg reflection Lippmann holograms,³ can satisfy all necessary conditions to be competitive with conventional techniques. These conditions are high diffraction efficiency values close to the theoretical limit, rectangular shape of diffraction efficiency spectral characteristics, low absorption/scattering losses (below1%), low coupling losses (below 5%), and optical efficiency of the compound holographic system close to its average diffraction efficiency within all spectra of interest. In the case of solar applications (inc1uding PV and TPV holoconcentrator systems), the last condition is especially difficult to satisfy because of the relatively wide range of the solar spectrum. To prove the advantages of reflection holograms (compared with transmission holograms) in broadband energy-related applications (solar, chemical, etc.), the wave-tracing kinematic model was applied to 1-D-limited 3-D holographic Bragg structures with a well-defined grating vector. The model was based on the generalized solid-state physics Wulf-Bragg formalism.⁴

© 1985 Optical Society of America