Optical Filtering Technique for Suppressing Nonlinear Pulse Distortion caused by Long Transmission Distance

Abstract

The optical pulses of around a few pico-seconds required for an ultra-high speed transmission are extremely distorted by the higher order dispersion in the transmission line. Especially in non-repeated transmission, high bit rates require the high fiber-input power to achieve a sufficient signal to noise ratio, thus leading to pulse degradation due to the combination effect of fiber nonlinerity and fiber dispersion. This paper demonstrate a new approach to overcome this pulse distortion with the use of optical filtering. The transmitted pulses generate dispersive waves at the trailing edge which is shifted by fiber nonlinearity into the normal dispersion region, while the main part of pulse spectrum moves to the anomalous dispersion region[1]. Therefore, optical filtering can remove the pulse distortion at the trailing edge[2]. This technique is experimentally confirmed by ultra-short pulse long-distance transmission.