The degree of linear polarization (DOLP) expressions at any polarizer direction (PD) was deduced based on the Stokes vector and Mueller matrix. The outdoors experiments were carried out to demonstrate the expressions. This paper mainly explored the DOLP-image-Contrast (DOLPC) between the target image and the background image, and the PD and RGB waveband that be considered two important influence factors were studied for camouflage target polarization detection. It was found that the DOLPC of target and background was obviously higher than intensity image. When setting the reference direction that polarizer was perpendicular to the incident face, the DOLP image of interval angle 60 degree between PD and reference direction had relatively high DOLPC, the interval angle 45 degree was the second, and the interval angle 35 degree was the third. The outdoors polarization detection experiment of controlling waveband showed that the DOLPC results was significantly different to use 650nm, 550nm and 450nm waveband, and the polarization detection performance by using 650nm band was an optimization method.
Imaging unevenly is a problem to work out in laser display. The cause of imaging unevenly is analyzed in the paper firstly. In order to get even illumination, we use rotating polygon mirror with two-dimensional scanning and lens array to make the intensity distribution of Gaussian function become approximate even distribution. In order to reduce speckles, a rotating diffuser is used in our laser display system to produce the maximum speckle reduction with the minimum number of distinct phase Patterns. Finally the method is experimentally verified by taking example of green light.