Intensity fluctuations in thermal light with orthogonally polarised multiple-peak spectrum

Aleksey A. Orlov, Anatolii S Chirkin

The propagation of partially coherent single-mode and two-mode radiations with orthogonal polarisations in media with a cubic optical nonlinearity is considered for the first time. Partially coherent light is regarded as a superposition of coherent and thermal radiations. It is shown that quantum and thermal fluctuations of a quadrature component may be suppressed in the self-interaction of partially coherent single-mode light. In the case of the self-interaction of incompletely polarised light can suppress fully only those fluctuations of the Stokes parameters (S 2 or S 3 ), which are associated with quantum fluctuations of the coherent component.

T. Sh. Iskhakov, Alessia Allevi, Dmitry A. Kalashnikov +4 more

M. I. Dykman, G. P. Golubev, D. G. Luchinsky +2 more

Fluctuational transitions between stable states of an all-optical lumped-parameter bistable system have been observed. The dependences of the transition probabilities, and of the statistical distribution of the transmitted-light intensity, on the intensities of incident light and noise have been investigated. Two types of stochastic modulation, that of the incident-light intensity and that of the device itself, have been used. They correspond to multiplicative and additive noise for the intracavity-phase gain and give rise to qualitatively different pictures of the fluctuations. In particular, for the latter type of noise the logarithm of the statistical distribution of the transmitted-light intensity is described by a multibranch function, and the peaks of the distribution are strongly asymmetric. The onset of a zero-frequency peak in the power spectrum of the transmitted light in the range of the kinetic phase transition has been observed. The experimental data are in good qualitative and quantitative agreement with the theory.

Mario Corti, Vittorio Degiorgio

Cyrus D. Cantrell, M. Lax, Wallace Arden Smith

W. Vogel, D.‐G. Welsch, K. Wódkiewicz

A method of calculation of multiple-time correlation functions of the resonance fluorescence light from a two-level atom driven by a realistic laser field with phase and amplitude fluctuations is developed. Both kinds of fluctuations are assumed to be Gaussian. The phase fluctuations are treated in the phase-diffusion model. The averaging over the amplitude fluctuations can be performed in a closed way when the relative mean-square amplitude fluctuation is small compared with the ratio of the amplitude correlation decay rate to the characteristic atomic relaxation rate. There is no restriction to Markovian amplitude fluctuations. Arbitrary values for the mean Rabi frequency are allowed. Results are presented for the intensity, the intensity correlation function, and the spectrum of the fluorescent light. It is shown that even in the case when the relative strength of the amplitude fluctuations is small, significant effects can occur due to the finite correlation length of the fluctuations. The results for fast amplitude correlation decay correspond to the situation without amplitude fluctuations. When the correlation time of the amplitude fluctuations becomes comparable with the atomic relaxation times, the Rabi oscillations of the intensity and the intensity correlation function are nearly washed out, and non-Lorentzian line shapes for the side peaks in the spectrum are observed. It is found that the ratio of the heights of the central peak to the side peak increases with increasing correlation time.