On the basis of the Attenuated Total Reflection(ATR) principle
a novel solution for the filter design is presented.As we know
high-order guided modes excited in ATR configurations are highly wavelength dependent.Utilizing this characteristic and the electro-optic characteristics of organic polymers
a newly-structured tunable filter is fabricated with merits of lower insertion loss
simpler fabrication process
lower cost and stronger stabilization as compared with other types of tunable filters.Moreover
a narrowband tunable filter with 0.4 nm bandwidth can be obtained by further parameter optimization.