Widely tunable 3.4 μm band difference frequency generation using apodized χ(2) grating

We achieved apodization in a quasi-phase-matched wavelength converter. The new design yields a large bandwidth and a flat phase-matching response with a high conversion efficiency. Using the method, we demonstrate widely tunable 3.4 mu m band difference frequency generation in a LiNbO3 ridge waveguide. (c) 2007 Optical Society of America.