Increasing the Sensitivity of Interferometric Measurements Using Squeezed Light

In this work, we investigate the possibility of using quantum squeezed light generated during propagation of ultrashort optical pulses in a medium with third-order (Kerr) nonlinearity to increase the sensitivity of interferometric measurements. In a demonstration experiment, using squeezed light states obtained in optical fibers with third-order nonlinearity, we experimentally demonstrated an increase in the interferometer sensitivity by 4 dB beyond the shot noise level, whereas in previous demonstrations, squeezed vacuum states generated in media with quadratic nonlinearity were used to increase the sensitivity. For this purpose, we used an original system based on nonlinear polarization-maintaining fibers to obtain squeezing of the quantum uncertainty of the polarization state of femtosecond pulses better than –5 dB, which has high long-term stability without active stabilization systems.