Temperature-Insensitive Dual-Comb Filter Based on Multimode Interference Ti:LiNbO3 Waveguide

Abstract

A temperature-insensitive dual-comb filter has been demonstrated for the first time by multimode interference based on a Ti : LiNbO3 channel waveguide. The phase difference between comb filters was about 180 degrees. We only observed less than +/- 0.125-nm variation of the center wavelength of the filter during temperature change from 20 degrees C to 50 degrees C. The measured extinction ratio and channel spacing of the comb filter were about -25 dB and 3.2 THz, respectively.