Seed-source tuning of a broadband noncollinear optical parametric generator based on periodically poled LiNbO3

We report a noncollinear optical parametric generator (OPG) using periodically poled LiNbO 3 (PPLN) pumped by a Nd:YAG laser. Signal tuning is achieved from 1.58 to 1.81 μm by angular rotation of the PPLN crystal. A signal linewidth of 68 nm was found at 1.76 μm. A 532-nm-pumped narrow-linewidth OPG is employed for its idler to serve as a seed source for the Nd:YAG-pumped broadband OPG. Tuning the seed wavelength only, tuning of the noncollinear OPG is achieved, with its linewidth reduced to 1.7 nm throughout its bandwidth. Such a system can be employed for wavelength division multiplexing, optical coherence tomography, and spectroscopy.