Length of Polarization-Correlation Based on Speckle Pattern for Optical Coherent Detection

A length of polarization-correlation (LPC) based on speckle pattern of the non-uniform spatial polarization distribution is proposed and measured by using the classical measurement method of the Stokes polarization parameters for optical coherent detection. The LPC, which depends on the material of the scattering medium, is emphasized on the speckle scale. A gradually expanding window centered at the brightest spot of the speckle pattern, is designed to calculate the degree of polarization (DOP) of different speckle sizes. Moreover, the magnitude of LPC is equal to the speckle size that reaches a particular threshold on the DOP curve. It is experimentally demonstrated that the LPC is exploited to not only investigate the nature of the polarization changes between different speckle sizes, but also be combined with coherent efficiency. This study can provide new insights of speckle depolarization in optical coherent detection and open new opportunities for improving coherent efficiency.