Dynamics of GB-speckles with a small number of scatterers

A method for generating dynamic GB-speckles, formed during diffraction of focused Gaussian beams by moving virtual rough surfaces, obtained for two nucleotide sequences (the ompA genes of the Chlamydia psittaci GR9 and AMK-16 strains), is proposed. The statistical characteristics of the 1st- and 2nd-order statistics of GB-speckles, formed at a small number of scattering events, are studied. The difference in the manifestation of the Doppler effect in the dynamics of GB-speckles and for speckles, formed with a small number of scatterers, produced by light diffraction on physically-existing rough surfaces and in scattering micro-streams is revealed. The problems of interference of dynamic GB-speckles are considered. A new technique for detecting individual single nucleotide polymorphism in nucleotide sequences using the interference of dynamic GB-speckles is proposed.

Beam Propagation Factor of Hollow Higher-order Cosh-Gaussian Beams

Based on the second-order moments definition, we investigate in this paper the beam propagation factor of new mathematical model of Hollow higher-order Cosh-Gaussian (HhCG) beams. Two analytical formulae of the M2-factor of HhCG beams are derived. Moreover, numerical simulations are developed to illustrate the effects of the beams orders n and l, the parameter δ and the beam waist ω0 on the M2-factor. The result shows a more general characteristic of higher-order Cosh-Gaussian, Cosh-Gaussian and the fundamental Gaussian beams can be obtained as specials cases of HhCG beams.