A theoretical investigation on the propagation properties of Hollow Gaussian beams passing through turbulent biological tissues

Hollow Gaussian beam (HGB) is a new mathematical model to describe a dark hollow beam with circular and noncircular symmetry. By expanding the HGB as a superposition of a series of Hermite-Gaussian mode, the analytical formulae of the considered beam passing through turbulent biological tissues are investigated and developed, based on the extended Huygens-Fresnel integral. Our results indicate the effect of the turbulent biological tissues on the propagation properties of the HGB. The present study shows that the circular and the elliptical HGB propagating in biological tissues will evolve into Gaussian like beam in the far field, and the central irradiance of the HGB propagating in biological tissues rises more rapidly with lager constant of refraction index structure Cn. We also calculate the formulae of the effective beam size of the HGB in turbulent biological tissues which provide a convenient way to learn the spreading properties of the considered beam. (C) 2017 Elsevier GmbH. All rights reserved.