The variation laws of mutual coherence function in laser projector with moving diffuser for speckle reduction are
studied based on the partly coherent theory. We take the magnification of lens and its spread function into consideration,
it gives us a method to weigh the speckle reduction and the loss of optical energy while using the moving diffuser for
speckle reduction, and it points out the selection of diffuser slice for laser display.
The film of holographic two-dimensional (2D) photonic crystal is used for the led illumination system. According to the decorative patterns, the structure sizes of 2D photonic crystal and relevant led luminaire have been reasonably designed. Then the master mask of 2D photonic crystal is produced with the method of multiple-beam interference. With the experiment of LED illumination, the results show that it is able to meet the expected decorative patterns of LED illumination. While the master mask is used to copy optical coating of polycarbonate, it will provide a better option for LED decorative illumination under low cost.