Methods Of Imaging With Photoelastic Modulators

Dr. John Freudenthal, Application Scientist

In this brief, we highlight a range of options to utilize photoelastic modulators with imaging systems to generate full field polarimetric measurements using photoelastic modulators. Photoelastic modulators (PEMs) are resonant polarization modulation tools. PEMs operate by the photoelastic effect controlled with a piezotransducer at the resonant frequency of both the optical window and piezotransducer.

Due to the resonant nature of the polarization modulation, the change in polarization can not be directly controlled and happens at the natural resonant frequency of the device. The resonant frequency of most polarization modulation devices is in the range of 40kHz-60kHz, and as such, the change in polarization is often faster than most imaging systems frame rate.