Laser detection using liquid crystal polarization modulators

Abstract

Lasers can be identified by their relatively long coherence lengths using interferometry. A Mach-Zehnder interferometer incorporating liquid crystal polarization modulators is demonstrated as a means of low-cost, robust laser detection. Temporal modulations, as a signature of coherence, can be induced by modulating polarization changes in liquid crystal modulators using low voltages. Sensitivities of <10 nW can be achieved. The suitability as a means of laser detection is discussed.

Design and Implementation of a Promising Optical Subsystem With a Sky Camera for Laser Warning Systems

“…The design and implementation of the optical system is constrained with the LWS overall size. An optical system composed of six lenses was used to implement LWS [12]. However, the size and the number of the lenses can be reduced to reduce the overall size.…”