Path length modulation technique for scatter noise immunity in squeezing measurements

Opt Lett. 2013 Jul 1;38(13):2265-7. doi: 10.1364/OL.38.002265.

Abstract

We present a technique for frequency shifting scattering induced noise on squeezed light beams, providing immunity from scattered light while preserving the squeezed states. Using a 500 Hz pre and postsqueezing apparatus path length modulation, we show up to a 20 dB reduction in scattering induced noise while recovering squeezing measurement below the shot noise level. Such a technique offers immunity to spurious scattering sources without the need for optically lossy isolation optics.