Laser detection using liquid crystal polarization modulators

TL;DR

This paper presents a low-cost, robust laser detection method using a Mach Zehnder interferometer with liquid crystal polarization modulators to identify lasers based on their coherence properties.

Contribution

It introduces a novel interferometric technique employing liquid crystal polarization modulators for sensitive and low-voltage laser detection.

Findings

Sensitivity of less than 10nW achieved

Effective modulation of polarization signatures demonstrated

Suitable for low-cost, robust laser detection

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 less than 10nW can be achieved. The suitability as a means of laser detection is discussed.