| The parameteric down-converiont is a useful method to obtain non-classical state in quantum optics.(1). The analytical solution of the Fokker-Planck equation of Non-degenerate Optical Parametric Amplification (NOPA) for generation of squeezed light is presented. The maximum intra-cavity compression of squeezed light derived from the analytical solution is 1/16(vacuum fluctuations 1/4). To compare it with that of the previous result 1/8 of Degenerate Optical Parametric Amplification (DOPA), it seems that the squeezing for NOPA is superior to the squeezing for DOPA. (2). An analytical solution of the phase-mismatched Fokker-Planck equation and the amplitude quantum fluctuation after passing through the periodically inverted quasi-phase-matched (QPM) device are obtained. The calculated results for QPM device, conform to that of the Langevin equation in the case of no loss k=0, in the noise case k ≠0, mainly resorts to the solution of F-P equation. From which we can derive the knowledge about the dependence of squeezing on the loss coefficientk.The squeezing is nearly perfect for small loss k = 0.2×ε0, make a comparison between the QPM device and phase matched device at threshold k=ε0,our result 1/6.7 shows slightly ineffective than that of 1/8 in phase-matched device, thesqueezing decrease continually for loss k>ε0, near the vacuum fluctuations for verylarge loss. (3). A detailed analysis of the quantum fluctuations in a DOPA is given when the pump depletion is present. we first deduce the time-dependent linearly driven Fokker-Planck equation of the Degenerate Optical Parametric Amplification (DOPA) in the generalized positive- P representation and evaluate its exact solution. Both the above- and below-threshold behavior is calculated. Our results below threshold or near threshold conform to that obtained by the linear theory or perturbation series expansion near threshold. Above threshold, the short-time...
|
PDF Full Text Request