All-optical wavelength tuning in Ti:PPLN Šolc filter via the photorefractive effect

We demonstrate fine-wavelength tuning of a periodically poled Ti:LiNbO3 (Ti:PPLN) Šolc filter by use of the photorefractive (PR) effect. The center wavelength of a Ti:PPLN Šolc filter is controlled by the PR effect, which is induced by second-harmonic generation (SHG). The refractive index change caused by the PR effect is calculated from the measured shift in center wavelength from the Ti:PPLN Šolc filter. The experimental results show that all-optical fine-wavelength tuning in a Ti:PPLN Šolc filter is possible by the use of a second-order nonlinear effect and that a Ti:PPLN waveguide has much higher resistance to PR damage than a Ti:LiNbO3 waveguide. The measured wavelength tuning rate as a function of the pump beam power is about − 0.033 nm/mW.