A Design Of Wavelength-selective Switch Based On LCOS And Research Of It's Crosstalk Reduction

With the development of optical communication, the quality and capacity of the optical signal transmission are higher requirements. Wavelength selective switch(WSS) is playing an important role in improving communication capacity and thus becames a global research focus in optical communication. By theoretical and experimental analysis, the LCOS-based WSS is studied in this paper, as follows:The structure and the working principle of phased LCOS is introduced; and consider the light transmission in the liquid crystal device, we get its reflectance and phase change formula by the analysis of its reflectivity Jones matrix, then the parameter space analysis is used to get the best work mode of the LCOS; and we introduces the specific methods to achieve the beam deflection, gives its modulation model and structure diagram.Light path of 1×4 LCOS-based optical filter is designed. We design its overall structure, and select all the device depending on this overall structure and the requirements of the subject, combined with the actual situation used in the experiments; we also expand the analysis to M×N structure of LCOS-based wavelength selection switch, and come to the formula of modulation order that LCOS modulate on the beam, in order to realize the 4 × 4 structure; The implementation methods of LCOS for 2-dimensional beam steering is explored, by the way, we verify the feasibility of the design.The reasons of crosstalk are analyzed, and propose a method to reducing crosstalk combining the drawing method of phase diagram.Based on the analysis results above, we design and manufacture the WSS prototype which has a 1×4 structure. The experimental results show that it's insertion loss is less than 6 dB, crosstalk is below- 35 dB. This results show that the designed WSS has simple structure, low insertion loss, low crosstalk, and many other advantages.