On the Coherent Scattering of Light

Guang S. He

When a high-intensity laser beam passes through a transparent and homogeneous optical medium, the induced light scattering may manifest the properties of stimulated radiation characterized by threshold requirement, high directionality, and high brightness. This is the stimulated scattering of intense coherent light. Discoveries and studies of various types of stimulated scattering effects have provided a much deeper and more comprehensive understanding of interactions between the intense coherent light and matter. On the other hand, devices based on stimulated Raman scattering, stimulated Brillouin scattering, and stimulated spin-flip Raman scattering can be employed as highly efficient tunable frequency shifters of coherent light. Stimulated Kerr scattering can be used to generate a super-broadband coherent light and to investigate the molecular anisotropy of liquids. In addition, the recently developed stimulated Rayleigh–Bragg scattering and stimulated Mie scattering can significantly reduce the threshold requirement, and provide a highly efficient no-frequency-shift optical phase conjugation wave.

Chandrasekhara Venkata Raman, C. S. Venkateswaran

M. J. Beranro, John B. DeVelis, A. S. Marathay

Alan V. Durrant

Existing theories of level crossing and modulation effects in the light scattered from optically thin vapours are restricted to cases where the light from different atoms is either completely incoherent (lateral scattering) or completely coherent (forward scattering). In the latter case the resonances are Doppler broadened equivalents of the well known Lorentzian forms predicted for lateral scattering. The more general case of partial coherence of the scattered light, which might be expected at small scattering angles, has not previously been considered. In this paper the degree of coherence of the scattered light has been formulated in terms of an autocorrelation function. For scattering from an ideal gas the autocorrelation function may be split into two terms representing complete incoherence and complete coherence. The predicted resonances for scattering into an arbitrary direction are mixtures of the Lorentzian and Doppler broadened forms, but the latter have a strong angular dependence that effectively restricted their observation to the small angular range associated with diffraction from the active volume of the vapour.

Salim Balik, P. Kulatunga, Charles I. Sukenik +3 more

We report experimental observations of polarization-dependent coherence loss occurring in strong-field multiple scattering of light in ultracold atomic 85Rb. A measure of coherence in multiple light scattering is the degree of contrast of the coherent backscattering enhancement from the vapour. For resonance saturation parameters up to 9, we see light-polarization-dependent modification of the backscattering enhancement, suggesting that inelastic atomic light scattering and dynamic atomic magnetization may play important roles in the multiple scattering process for 85Rb.

Oleg N. Gadomsky, V. R. Nagibarov