Flexible all-optical wavelength conversions of 1.57-ps pulses exploiting cascaded sum- and difference frequency generation (cSFG/DFG) in a PPLN waveguide

Flexible all-optical wavelength conversions of ps-pulses based on cascaded sum- and difference frequency generation (cSFG/DFG) are proposed and experimentally demonstrated using a periodically poled lithium niobate (PPLN) waveguide. The pulsed signal, with a 40 GHz repetition rate and a 1.57 ps pulse width is adopted. Fixed-in variable-out (tunable), variable-in fixed-out and variable-in variable-out wavelength conversions are successfully realized with three proposed tuning schemes. Both wavelength down- and up-conversion are simultaneously observed. PACS 42.65.Ky; 42.65.Wi; 42.65.Re