Method to reduce sidelobes of multistage Lyot filters

We propose a method to reduce sidelobes of multistage Lyot filters by substituting certain stages with two-plate fan Solc stages. Parallel-aligned nematic liquid crystal (LC) cells are used as variable retarders to compose multistage Lyot LC tunable filters (LCTF). The simulation of a four-stage Lyot LCTF and a tunable filter, comprising two stages of Lyot filter and two stages of two-plate Solc filter, are compared. With this method, the sidelobes are reduced and the full width at half-maximum intensity of transmission peak is also reduced. Experimental results and theoretical analysis are presented in detail to verify this method.