Waveguide-Type Wavelength-Tunable Šolc Filter in a Periodically Poled Ti : LiNbO $_3$ Waveguide

We have demonstrated the waveguide-type tunable wavelength filtering (Sole filter) characteristics in an 80-mm-long periodically poled Ti: LiNbO
₃
(Ti: PPLN) channel waveguide which has a domain period of 16.6 mum. At room temperature (25degC), the center wavelength and the full-width at half-maximum of the filter were about 1273.3 and 0.21 nm, respectively. By changing the temperature of the Ti: PPLN waveguide, we have tuned the center wavelength of the filter with a wavelength tuning rate of -0.683 nm/degC. Also, the characteristics of the waveguide-type Sole filter based on a Ti: PPLN waveguide were compared with those of a bulk PPLN device.