Study On The Propagation Properties Of LGCSM Beam In Non-kolmogorov Turbulence And The Optical Trapping Properties Of The Focused LGCSM Beam

Laser beam has a high level of coherence.Studies have shown that the intensity distribution of partially coherent beam is more uniform than the completely coherent beam.And the partially coherent beam is less affected by atmosphere turbulence during propagation.The related structure of the partially coherent beam studied in the past is Gaussian function distribution.In fact,by controlling the spatial correlation structure of the beam,the partially coherent beam with a special correlation structure can be obtained.Due to its unique properties,the partially coherent beam with a special correlation structure has drawn more and more attention in recent years.The primary research contents are as followings:(1)Based on the extended Huygens-Fresnel principle,the cross-spectral density function and the second-order moments of the Wigner distribution function,we have derived the analytical formulas for the average intensity,the rms angular width,and the M ~2-factor of LGCSM beam propagating in non-Kolmogorov turbulence.The effect of beam parameters and turbulence strength on the average intensity,the rms angular width,and the M ~2-factor of LGCSM beam has been analyzed.It is found that the LGCSM beam is significantly less affected by non-Kolmogorov turbulence compared with GSM beam.(2)Based on the Collins formula and the Rayleigh scattering theory,the radiation forces and the trap stiffness on Rayleigh dielectric sphere induced by a focused LGCSM beam are theoretically studied.It is found that by changing the beam parameters,the light intensity distribution can be adjusted.So that two types of Rayleigh dielectric particles with different refractive indices can be trapped by a focused LGCSM beam.(3)Based on the Richard-Wolf vector diffraction theory,the tight focusing properties of elliptical symmetric Laguerre-Gaussian vector beams are studied.It is found that the intensity distribution will split and the intensity profile could be adjusted by changing the beam parameters.(4)Two sets of experimental setups were set up based on the Mach-Zehnder interferometer,which were used to generate cylindrical vector beam and elliptical symmetric Laguerre Gaussian vector beam respectively.The experimental results are compared with the theoretical simulation results.