Integrated Optical, Acoustically Tunable Wavelength Filter

An integrated optical, acoustically tunable wavelength filter, consisting of a combination of TM-TE converter and integrated polarizer in LiNbO3, is demonstrated. The filter bandwidth is 2.8 nm; the center wavelength can be tuned from λ = 1.45 pm to λ = 1.57 pm by adjusting the driving acoustic frequency. Due to the combined acoustical/optical strip guide structure, used in the mode converter, a very low acoustic drive power of only 9 mW is required.