Tunable multi-wavelength filter in periodically poled LiNbO(3) by a local-temperature-control technique

A tunable multi-wavelength filter can be realized in periodically poled LiNbO3 by using a local-temperature-control technique. In this paper, a tunable single-wavelength and double-wavelength filter of this kind is experimentally demonstrated. In our experiment, the output transmissivity peaks of the filter can be tuned to any wavelengths by properly setting the local temperature distribution along the sample. The dependence between the wavelength shift and temperature change is Deltalambda/DeltaT approximately -0.598nm/ degrees C. The wavelength tuning range of such filter is determined by the tuning range of the temperature control device according to this Deltalambda/DeltaT relation.