Analysis of design parameters of holographic solar concentrators for large acceptance angle

Abstract

This paper presents a detailed analysis of design parameters of holographic solar concentrators for large acceptance angle. It has been shown that by optimizing the design parameters like depth of the film (d), refractive index modulation (n 1 ) and fringe spacing (∧) the acceptance angle of holographic-concentrators can be increased appreciably with reasonably good diffraction efficiency over the desired wavelength range. Theoretical analysis revel that angular acceptance of ± 2 degree with 10 percent fall in diffraction efficiency from maximum can be achieved for for n 1 = 0.0954, ∧ = 0.8696 ¼m and d = 4¼m having appreciable diffraction efficiency over the wavelength range of about 0.6 ¼m to 1.5 ¼m. Also, for n 1 = 0.0954, ∧ = 0.8696 ¼m and d = 12¼m we may achieve an angular acceptance of ± 2 degree at 90 percent diffraction efficiency that allows mainly wavelengths of around 0.7 to 0.9 ¼m to diffract through it with high diffraction efficiency.