Higher-Order Amplitude Squeezing in Six-Wave Mixing Process

Abstract

We investigate theoretically the generation of squeezed states in spontaneous and stimulated six-wave mixing process quantum mechanically. It has been found that squeezing occurs in field amplitude, amplitude-squared, amplitude-cubed, and fourth power of field amplitude of fundamental mode in the process. It is found to be dependent on coupling parameter "g" (characteristics of higher-order susceptibility tensor) and phase values of the field amplitude under short-time approximation. Six-wave mixing is a process which involves absorption of three pump photons and emission of two probe photons of the same frequency and a signal photon of different frequency. It is shown that squeezing is greater in a stimulated interaction than the corresponding squeezing in spontaneous process. The degree of squeezing depends upon the photon number in first and higher orders of field amplitude. We study the statistical behaviour of quantum field in the fundamental mode and found it to be sub-Poissonian in nature. The signalto-noise ratio has been studied in different orders. It is found that signal-to-noise ratio is higher in lower orders. This study when supplemented with experimental observations offers possibility of improving performance of many optical devices and optical communication networks.

Higher-Order Squeezing of a Generic Quadratically-Coupled Optomechanical System

“…Hillery has shown that amplitude squared squeezed states can be used for reduction of noise for nonlinear optical systems [25]. Higher-order squeezing has useful application in prototype gravitational wave detection [26], higher harmonic generation [27,28], hyper-Raman scattering [29], parametric amplification [30], Six-wave mixing process [31], and so forth.The present article is organized as follows: at first we describe the model Hamiltonian of a generic quadratically coupled OMS and its perturbative solutions for Heisenberg equation of motion corresponds to various field modes. Using the criteria for different higher order squeezing we have investigated the existence of squeezed states for various field modes.…”