Fig. 1. Structure of proposed comb filter

Fig. 2. Simulated transmission spectra of filter. (a) Rotating PC2 when θ₁－α＝π4; (b) rotating PC1 when θ₁－β＝π4

Fig. 3. New channel interval combinations. (a) Channel interval determined by PMF1; (b) channel interval determined by PMF2

Fig. 4. Fluctuation of extinction ratio when PC2 is fixed and PC1 is adjusted. (a) Effect of PC1 on transmission spectrum；(b) effect of PC1 on amplitude of transmission spectrum

Fig. 5. Experimental setup of filter with improved structure

Fig. 6. Spectra with maximum amplitude obtained in experiment. (a)(b) Channel interval is 0.65 nm; (c)(d) channel interval is 0.34 nm

Fig. 7. Experimental setup of MWFL based on dual Lyot filter

Fig. 8. Multi-wavelength output spectra. (a) Channel interval is 0.65 nm; (b) channel interval is 0.34 nm