Sub-shot-noise measurement with fiber-squeezed optical pulses

Abstract

A novel scheme employing two pulses separated by a short time delay is used to cancel the phase noise from guided-acoustic-wave Brillouin scattering in a fiber ring interferometer. The dual-pulse-excited fiber ring is used to generate squeezed vacuum that, when injected into a measuring Mach–Zehnder interferometer, improves its sensitivity by 3 dB beyond the shot-noise limit.