Polarization effects for polarization-squeezed light formed in a medium with third-order nonlinearity

V. N. Beskrovnyi, A. S. Chirkin

A. S. Chirkin, V. V. Volokhovskii

The influence of losses and thermal noise on the polarization-squeezed light formation in a medium with third order nonlinearity has been analysed. A method of analysis based on the delta-correlation property of noise was developed. Mean values and variances of some Stokes parameter of the light was calculated. It was shown that optimal interaction length for effective fluctuation suppression in the Stokes parameters is determined by damping constants, noise level, and radiation intensity.

A. P. Alodzhants, Sergei M. Arakelyan, A. S. Chirkin

Harneet Kaur Gahir, Pratima Sen, Pranay K. Sen

The roles of the asymmetry of coherent light and of an active medium in squeezed-state generation in a weakly noncentrosymmetric semiconductor are discussed. It is suggested that origin of medium asymmetry lies in the parity indefiniteness of the transition states, whereas field asymmetry is due to the polarization property of light. Third-order nonlinear optical susceptibility is obtained from the semiclassical density matrix approach, whereas the light-squeezing process is studied by use of Heisenberg’s equation of motion. The analysis is applied to GaAs that has been duly irradiated by a tunable nanosecond pulsed Co:MgF2 laser with its photon energy off resonant below the semiconductor’s band edge. It has been found that the effect of asymmetry on squeezed-state generation and photon number is finite only when both of the asymmetries are present simultaneously. One may also notice that the asymmetry improves the squeezing level and reduces the time span of squeezed-light generation.

Ranjana Prakash, Namrata Shukla

Jöran Bauchrowitz, Tobias Westphal, Roman Schnabel

The standard process for the production of strongly squeezed states of light is degenerate optical parametric amplification (OPA) below threshold in nonlinear dielectric media such as LiNbO3 or periodically poled potassium titanyl phosphate (KTP). Here, we present a graphical description of squeezed-light generation via OPA, visualizing the interaction between the nonlinear dielectric polarization of the medium and the electromagnetic quantum field. We explicitly focus on the transfer from the field's ground state to a squeezed vacuum state and from a coherent state to a bright squeezed state by the medium's second-order nonlinearity, respectively. Our pictures illustrate the phase-dependent amplification and deamplification of quantum uncertainties and give the phase relations between all propagating electromagnetic fields as well as the internally induced dielectric polarizations. The graphical description can also be used to describe the generation of nonclassical states of light via higher-order effects of the nonlinear dielectric polarization such as four-wave mixing and the optical Kerr effect.