Study on helicity flip of backscattered circular polarized light

Compared with the linear polarized light, circularly polarized light has more potential advantages, especially in suppressing the influence of the scattered light when detecting targets in turbid medium using the helicity of circularly polarized light. Based on the description method of classic single-particle polarization state, the helicity reversion and maintenance mechanism of the circularly polarized light is illustrated from the perspectives of scattering medium properties and scattering angle, and the backscattering helicity reversion characteristic of circularly polarized light is analyzed by Monte Carlo simulation method. The simulation results show that the helicity maintenance or reversion after single scattering depends on the properties of scattering medium and the size of scattering angle. After multiple scattering it is also related to the intersection angle between incident photon and photon receiving surface. Specifically the helicity flipping of backscattering circularly polarized light occurs in a low concentration of scattering medium or short distance transmission. But in the turbid medium namely high concentrations of scattering medium or long distance transmission, the helicity maintains its initial polarization state. © 2015, Chinese Laser Press. All right reserved.