Squeezing-enhanced simultaneous measurement of polarization angle and ellipticity beyond the shot noise limit

An experimental scheme is proposed for squeezing-enhanced simultaneous measurement of the polarization angle and ellipticity of laser beam beyond the shot noise limit. In the scheme, a two-mode squeezed light is exploited to enhance the sensitivity of the measurement of polarization rotation angle, and a single-mode squeezed light is used to improve the sensitivity of ellipticity measurement. Noise analysis is performed to show that the signal-to-noise ratios in both the measurements of polarization angle and ellipticity can exceed the shot noise limit. This work is expected to be of considerable interest for experiments such as the observation of vacuum magnetic birefringence, gravitational wave detection, spin–orbital interaction, material characterization, polarization microscopy, atomic magnetometer, or biomedical optics.