Cylindrical Beam Volume Holograms Recorded in Reflection Geometry for Diffuse Source Spectroscopy

Multimodal multiplex spectroscopy (MMS) has been demonstrated to increase the optical throughput of a spectrometer as opposed to that of conventional optical spectrometers [5] and has been implemented using three-dimensional photonic crystals [5] and spherical-beam volume holograms recorded in the transmission geometry [6-7, 9] as spectral diversity filters. While such efforts have resulted in compact and sensitive Fourier-transform holographic spectrometers [8], there still remains much room for performance improvements. Previous studies [6,7,9] have proven the utility of spherical-beam volume holograms recorded in the transmission geometry as spectral diversity filters for spectrometers. The role of the recording geometry in the performance of cylindrical-beam volume holograms as spectral diversity filters is investigated here. The transmission recording geometry is compared to the reflection recording geometry on the basis of the spectral operating range of the resultant spectral diversity filters.