Phased-Array Monolithic PEM for FT Spectrometry With Applications in Explosive Detection and CB Defense

摘要

We present the theory and multiphysics simulation of a novel type of photoelastic modulator (PEM) for use in ultra-high performance FT spectrometers with applications in the optical recognition of explosives and CB warfare agents. This new technology is based on the strain birefringence induced along a bar-shaped optical element by a phased array of piezoelectric transducers (PZT). Appropriate phase and amplitude relationships among the array PZTs ensure that induced birefringence oscillations add constructively and result in high total retardation. When used in PEM/FT spectrometers (Buican, 2006; Buican and Carrieri, 2004, 2006), monolithic virtualstack/ phased-array (VSPA) PEMs (Buican 2008) will provide ultra-high scan rates (to >105 interferograms/s); broad spectral range; high spectral resolution; and high light throughput.