Numerical analysis on fiber-nonlinearity compensation for 4ASK 100-km SSMF transmission by using electrical butterfly operation for received signal sidebands

Abstract

We investigated a novel demodulation technology based on our proposed electrical butterfly operation scheme which compensates for optical nonlinear distortion of conventional single-sideband (SSB) signals. In the scheme, phase-conjugated twin signals are transmitted as lower sideband (LSB) and upper sideband (USB) components of a dual sideband (DSB) signal modulated by a simple Mach-Zehnder modulator (MZM). The performance was evaluated by numerical simulation of 4-ary amplitude shift keying (4ASK) signals transmitted over a 100-km standard single mode fiber (SSMF). The error vector magnitude (EVM) was improved by about 20% when the input power was 10dBm, compared with a conventional SSB-4ASK signal.