Experimental Investigation of Single-to-Single and Single-to-Doual Channel Wavelength Conversion Between Picosecond Pulses

Based on cascaded second-harmonic generation and difference frequency generation (SHG+DFG) in periodically poled LiNbO3 (PPLN) waveguides,tunable wavelength conversion as well as single-to-dual channel wavelength conversion are proposed and experimentally investigated.A picosecond pulsed signal with 40 GHz repetition rate and 1.57 ps pulse width is adopted.The continues wave (CW) pump is provided by use of a fiber ring laser (FRL).Different from the conventional SHG+DFG-based conversion schemes,here the center wavelength of the signal is set at the quasi-phase matching (QPM) wavelength for the SHG process.By adjusting the pump wavelength,a tunable converted output idler wave is achieved.Moreover,single-to-dual channel wavelength conversion is also successfully observed by employing two pumps.