Coherent pseudo-mode representation of partially coherent surface plasmon polaritons.

We develop a general coherent (pseudo)-mode representation of partially coherent surface plasmon polaritons in the Kretschmann excitation geometry. We obtain explicit analytical results for coherent pseudo-modes of narrowband SPPs with Gaussian spectra and spectral correlations. We also evaluate the global degree of coherence of such SPPs which quantifies their overall coherence state within a given spatial domain.

Phase retrieval encryption in an enhanced optical interference by key phase constraint.

In this paper, we demonstrate a security system by using optical interference and phase retrieval algorithm (PRA) techniques. The modified PRA is proposed to encode the target image into random phase distribution. Optical and digital methods can be used for decryption.

Propagation of broadband gaussian Schell-model beams in the apertured fractional Fourier transformation systems.

On the basis of the fact that a hard-edged aperture function can be expressed as finite matrices with different weighting coefficients, we obtain the analytical formula for the propagation of the broadband gaussian Schell-model (BGSM) beam through the apertured fractional Fourier transformation (AFrFT) system. It is shown by numerical examples that the intensity distribution in the plane of a small fractional order is obviously influenced by the bandwidth when the BGSM beams propagate through the AFrFT system. Further extensions are also pointed out.

Second-order intensity-moment characteristics for broadband partially coherent flat-topped beams in atmospheric turbulence.

Based on the intensity moments and Wigner distribution function, the second-order moments for broadband partially coherent flat-topped (BPCFT) beams in atmospheric turbulence are studied. The beam width of BPCFT beams in atmospheric turbulence is larger than that in free space. The beam width of BPCFT beams in atmospheric turbulence is larger than that of broadband fully coherent flat-topped (BFCFT) beams in atmospheric turbulence.

Different models for a hard-aperture function and corresponding approximate analytical propagation equations of a Gaussian beam through an apertured optical system.

Beam profiles that consist of a sum of complex-Gaussian functions, a sum of polynomial-Gaussian functions and a sum of multi-Gaussian functions offset by some fixed amount are proposed as three types of model for a hard-aperture function. By expanding an aperture function into these models, approximate analytical propagation equations for a Gaussian beam through an apertured ABCD optical system are obtained. Comparison among these models themselves and among propagation characteristics of a Gaussian beam through these models are made.