We analyze the Raman interaction of Stokes and anti-Stokes sidebands with atomic coherence. The interaction is decomposed into a set of three-mode quantum operations. We represent these operations as two-mode squeezing and beamsplitters.
We investigate the dynamics of a two-mode stimulated Raman scattering model including propagation and the quantum correlations that develop between the Stokes and anti-Stokes fields. For example, under certain conditions two-mode squeezed states can result. We report results for quadrature squeezing and sum squeezing. Quadrature squeezing only occurs when the anti-Stokes coupling constant is larger than the Stokes coupling constant. The amount of squeezing increases as the damping of the material polarization is increased. \textcopyright{} 1996 The American Physical Society.
We investigate two-mode squeezing of compound Stokes-anti-Stokes modes propagating in a Raman coupler with a broad reservoir phonon system. Three types of squeezing: principal squeezing, generalized squeezing and sum squeezing are examined and their relations are identified. The definition of generalized squeezing is extended to an arbitrary number of modes, and a multimode uncertainty product is introduced. The quantum statistical properties of the optical fields propagating in the coupler are treated within the framework of the generalized superposition of the coherent signal and quantum noise. According to this model, generalized squeezing appears whenever the Glauber-Sudarshan quasidistribution does not exist as an ordinary function.
We investigate two-mode squeezing of compound Stokes-anti-Stokes modes propagating in a Raman coupler with a broad reservoir phonon system. Three types of squeezing: principal squeezing, generalized squeezing and sum squeezing are examined and their relations are identified. The definition of generalized squeezing is extended to an arbitrary number of modes, and a multimode uncertainty product is introduced. The quantum statistical properties of the optical fields propagating in the coupler are treated within the framework of the generalized superposition of the coherent signal and quantum noise. According to this model, generalized squeezing appears whenever the Glauber-Sudarshan quasidistribution does not exist as an ordinary function.
The non-classical effects of squeezing of light in coherent anti-Stokes Raman scattering (CARS) and coherent anti-Stokes hyper-Raman scattering (CAHRS) are investigated under the short-time approximation based on a fully quantum mechanical approach. In an idealized model CARS, the interaction is looked upon as a process involving absorption of a pump photon and emission of a Stokes photon, which is followed by absorption of a pump photon and subsequently emission of an anti-Stokes photon at a different frequency, whereas CAHRS is looked upon as a process involving absorption of two pump photons and emission of a Stokes photon, which is followed by absorption of two more pump photons and subsequent emission of an anti-Stokes photon at a different frequency. The coupled Heisenberg equations of motion involving real and imaginary parts of the quadrature operators are established. It is shown that squeezing in the Stokes and anti-Stokes mode in CARS is found to be dependent on amplitude-squared squeezing of the initial pump field while, in CAHRS, it is dependent on the fourth-order amplitude squeezing of the initial pump field. Higher-order squeezing can be converted to linear squeezing through these processes. It is also shown that squeezing is greater in CAHRS than the corresponding squeezing in CARS.