Wideband Intermodal Nonlinear Signal Processing With a Highly Nonlinear Few-Mode Fiber

Intermodal four-wave mixing can be exploited to perform nonlinear signal processing functionalities, such as all-optical wavelength conversion. Those functions can be used e.g. for switching applications in conventional single-mode fiber transmission systems. In this paper, we report on a sub-system to convert signals from various wavelengths in the C-band to various wavelengths in the L-band with a conversion bandwidth of more than 40 nm. The sub-system is based on a newly designed highly nonlinear few-mode fiber with specially engineered dispersion characteristics to enable wide-band intermodal four-wave mixing. We demonstrate the performance of the sub-system by converting highly spectral efficient quadrature-amplitude modulated signals from various wavelength in the C-band to various target wavelengths in the L-band with OSNR penalties of less than 1 dB at a target bit-error rate of 10
^-2
.