Wavelength Translation of Dual-Polarization Phase-Modulated Nyquist OTDM at Terabit/s

Wavelength translation is one of the key functions to realize spectral defragmentation in an elastic optical add/drop network. Optically translating the wavelength of Terabit/s signals is challenging in the sense that it requires a signal processing scheme to be independent of the symbol rate and modulation format, wideband, and highly efficient simultaneously. In this paper, we present an all-optical wavelength translation for a single-carrier 1.376-Tb/s dual-polarization quadrature phase-shift keying (DP-QPSK) Nyquist optical time-division multiplexing (OTDM) signal by using an all-optical wavelength converter which fulfills all of the basic requirements. A seamless wavelength translation covering almost C-band is achieved with a boost in OSNR thanks to the improved conversion efficiency. The system performance is measured by a polarization-insensitive coherent receiver using linear sampling which implements simultaneously the demultiplexing of the time-domain tributaries, polarization demultiplexing, and carrier-phase recovery for the dual-polarization phase-modulated OTDM signal. The employed receiving scheme, therefore, resolves one of the most shortcomings of the conventional OTDM receiver, which is polarization sensitive due to the use of nonlinear sampling.