Wavelength shifting of optical pulses through cascaded second-order processes in a lithium-niobate channel waveguide

We investigate the efficiency of wavelength shifting (generation of a pulse at the wavelength lambda(p)-Delta lambda from a signal at lambda(p)+Delta lambda under the action of a pump at lambda(p)) through a cascaded second-order process in a lithium-niobate channel waveguide. With a 58-mm-long Ti-diffused channel waveguide, lambda(p)=1.1 mu m (the wavelength of phase matching for the first step of the second-harmonic generation), Delta lambda of several nanometers and 20 ps pulse duration, wavelength conversion with unit efficiency is obtained with a pump pulse energy of the order of 10(2) pJ. (C) 1999 American Institute of Physics. [S0003-6951(99)01635-6].