Two alternative wavelength converters based on cascaded effect in different pumping methods

Two wavelength converters based on cascaded harmonic and difference frequency generation using a periodically poled lithium niobate waveguide under continuous-wave pumping or pulsed-wave pumping are demonstrated. The converted spectra, the temporal waveforms for 40 G non-return-to-zero pseudorandom binary sequence, are observed and compared to evaluate the performance of these two wavelength converters. The difference of bit transferring road and conversion process between two wavelength converters leads into different results. The information converting is completely transparent in the continuous-wave pumping wavelength conversion, whereas it is changed in pulsed pumping application.