Parametric intracavity conversion of squeezed light

Harry J. Kimble, J. L. Hall

Harry J. Kimble, J. L. Hall

Daniel B. Erenso

A degenerate parametric oscillator operating above threshold is studied when the cavity is injected by a broadband squeezed light at the pump frequency. Using the solution of the quantum Langevin equations for the signal and pump modes, we have studied the quantum fluctuations in the intracavity and transmitted field quadratures for the signal and pump modes. For the intracavity modes we studied the variance in the field quadratures, and for the transmitted modes we studied the spectra for the variance in the squeezed quadratures. Our results have revealed that the same relative cavity damping rates between the signal and the pump modes that predict enhanced squeezing in the intracavity do not necessarily predict enhanced squeezing in the transmitted modes.

Harry J. Kimble

Squeezed states of the electromagnetic field are characterized by a reduction of fluctuations for one of two quadrature phase amplitudes below the level of fluctuations for the vacuum state. This reduction is a manifestly quantum or nonclassical feature which is of great interest in its own right but also potentially important for precision measurement with sensitivity beyond the shot-noise or vacuum-state limit. We describe three different experiments in which squeezed light has been generated in our laboratory involving parametric downconversion, intracavity frequency doubling, and optical bistability with two-state atoms. By employing the squeezed light produced by a subthreshold optical parametric oscillator, we have achieved improvements in sensitivity beyond the vacuum-state limit for the detection of both phase and amplitude changes of the electromagnetic field. An alternate route to sensitivity beyond the vacuum-state limit is through quantum nondemolition measurement, where we have suggested and are implementing a scheme involving parametric conversion and polarization mixing.

А. В. Белинский, A. S. Chirkin

Noura Chabar, M’bark Amghar, Mohamed Amazioug +1 more

In this manuscript, we investigate the enhancement of the transfer of quantum correlations from squeezed light to movable mirrors within an optomechanical system. This enhancement was achieved via the injection of squeezed light in the cavities and via intracavity squeezed light. We quantify the entanglement between mechanical oscillators via logarithmic negativity. We demonstrate that entanglement is influenced by various factors, including the gain of the parametric amplifier, the squeezing parameter characterizing the squeezed light, the rate of the phonon tunneling process, the coupling strength of the photon hopping process and the bath temperature of the mechanical oscillators. We have shown that entanglement can be improved by a convenient choice of coupling strength in the case of the photon hopping process, as well as for specified values of the gain of the parametric amplifier.