Tunable Multi-Wavelength Filter In Periodically Poled LiNbO₃

In this paper we mainly studied a kind of tunable multi-wavelength filter realized in periodically poled LiNbO3 (PPLN) by using a local-temperature-control means. First we introduced the theories of Solc-type filter, electro-optical effect in the PPLN, and the filter based on the electro-optical effect in the PPLN. Then we carried out experiments to confirm the filter in the PPLN without an applied electric field and gave out some discussions. After that we discussed the theory of realizing a tunable single-wavelength filter in the PPLN by controlling the temperature, and carried out experiments and theoretical calculations, and did comparison and analysis between them including a correction for a parameter in the Sellmeier equation. At last we discussed the theory of realizing a tunable multi-wavelength filter in the PPLN by a local-temperature-control means, and carried out experiments and theoretical calculations, and did comparison and analysis between them.