Focusing pattern of cosh-Gaussian beam with polarization mixing cosine phase modulation.

Based on the vector diffraction theory, this paper focuses on the focusing pattern of cosh-Gaussian beams with polarization mixing cosine phase modulation and discusses the focused optical intensity under different parameters in detail. The results that show by adjusting the polarization parameter , a tunable focal shift and a continuous shifting of focus on both directions of the optical axis can be achieved and the component that dominates the intensity distribution of the total field can be changed. When the tunable parameter is positive, the optical chain with tunable length can be structured by increasing . When is negative, there will appear one special optical trap focus mode by which the number of optical traps can be changed by tailoring . When the phase modulation parameter increases, the focal pattern will wholly enlarge and stretch along the radial direction, changing from two intensity peaks to six optical chains. By increasing the decentered parameter , the shape of the light intensity distribution in the focusing region can be remarkably adjusted. Besides, by combining the theories and analyzing the field patterns in the transverse plane, there is an electric field intensity dependence on the azimuthal angle . Those novel findings may be helpful in the applications such as optical manipulation, optical focusing, and imaging.