Development of highly cascadable wavelength converter for all-optical networks

In this invited talk, we will review our recent development of an all-optical wavelength converter which satisfies the requirements for applications in practical all-optical networks. While providing a wideband conversion for almost all the C-band, excellent performance with dual-polarization quadrature phase shift keying (DP-QPSK) signals show a true modulation format independence with phase preserving and polarization insensitive operations. The converter features a counter-dithering pump scheme for cascaded dual-stage degenerate four wave mixing (FWM) processes to suppress the stimulated Brillouin scattering (SBS) in highly nonlinear fiber, and thus significantly improve the conversion efficiency, making it a low-loss and low-noise conversion. As a result, the total noise figure of the wavelength converter is reduced to 6.2 dB which is comparable to an EDFA. The cascaded operation of the wavelength converter is also investigated in a wavelength translating loop, showing negligible impacts of the phase noise transferred from pump signals on the idlers, or residual phase noise induced by the counter-dithering scheme. The obtained high cascadability as that of an EDFA indicates the true practicality of the developed wavelength converter for real system use.