Design And Fabricate Of Polarization Beam Splitter Grating

The traditional method for orthogonal polarizing beam splitter used by natural birefringence crystal or multilayer dielectric film, however, the former is cumbersome and the latter is costly. They can’t fulfill the update optical system’s demand. When the grating period is the order of incident wavelength and the groove depth is comparable to the period, the grating shows an interesting property of polarizing. Therefore, the grating can be designed as polarizing beam splitter.In this paper, we designed two kinds of polarizing beam splitters, the fused silica grating as transmission splitter and the golden grating as reflection splitter. We fabricated the reflection grating in the experiment and measured the properties of the grating. The main work of this paper as following:1. We used the modal method to design the fused silica transmission grating for 532nm laser beam splitter. There exits four kinds of grating as polarizing beam splitter. The fabrication tolerances and properties of the orthogonal polarizing beam splitters are analyzed by using rigorous coupled-wave analysis method. It is shown that all of these gratings have large fabrication tolerances and excellent properties. However, the transmission grating need large groove depth compared to the grating period.2. We used the rigorous coupled-wave analysis method to design the golden reflection grating for 532nm laser beam splitter. The sinusoidal golden grating, with period 277.78nm and groove depth 90nm, can diffract the TE polarization laser to the zero order and the TM polarization laser to the minus first order. The analysis of grating properties shows that the grating can be fabricated in the experiment and can be duplicated.3. Through the exposure holography, the IBE etching and the vacuum coating, we fabricated the reflecting grating which coated aluminum in the experiment. We measure the diffraction efficiency of the grating. It shows that the absolute diffraction efficiency of the grating meet the business product and the relative diffraction efficiency in accordance with the theoretical simulation.