Broadband Gerchberg-Saxton algorithm for freeform diffractive spectral filter design.

A multi-wavelength expansion of the Gerchberg-Saxton (GS) algorithm is developed to design and optimize a surface relief Diffractive Optical Element (DOE). The DOE simultaneously diffracts distinct wavelength bands into separate target regions. A description of the algorithm is provided, and parameters that affect filter performance are examined.

Spectrum splitting metrics and effect of filter characteristics on photovoltaic system performance.

During the past few years there has been a significant interest in spectrum splitting systems to increase the overall efficiency of photovoltaic solar energy systems. However, methods for comparing the performance of spectrum splitting systems and the effects of optical spectral filter design on system performance are not well developed. This paper addresses these two areas.

Ultra light-trapping filters with broadband reflection holograms.

Significant optical absorption enhancement can be achieved by incorporating optical diffusers in the thin-film silicon photovoltaic (PV) cells. Absorption can be increased further by angular and spectral selective filters. In this work the properties of volume reflection holograms are examined for realizing ultra light-trapping filters for thin film silicon photovoltaic cell applications.

Silicon oxide nanoparticles doped PQ-PMMA for volume holographic imaging filters.

Holographic imaging filters are required to have high Bragg selectivity, namely, narrow angular and spectral bandwidth, to obtain spatial-spectral information within a three-dimensional object. In this Letter, we present the design of holographic imaging filters formed using silicon oxide nanoparticles (nano-SiO(2)) in phenanthrenquinone-poly(methyl methacrylate) (PQ-PMMA) polymer recording material. This combination offers greater Bragg selectivity and increases the diffraction efficiency of holographic filters.

Temperature dependence properties of holographic gratings in phenanthrenquinone doped poly(methyl methacrylate) photopolymers.

We examine the temperature dependence of edge-illuminated holographic filters formed in phenanthrenquinone doped poly(methyl methacrylate) (PQ/PMMA) operating at 1550 nm. It was found that the thermally induced change to the refractive index and volume can be used to select the wavelength filtered by the grating. The temperature can be varied over a range of 15 degrees C without introducing noticeable hysteresis effects.