Raman Amplification for Nonlinearity Compensation in a Fiber Optic Link by Optical Phase Conjugation System

This study looks into the use of an optical phase conjugation (OPC) technique in conjunction with a Raman amplifier as a means of reducing the impact of fiber nonlinearities in dense wave division multiplexing (DWDM) transmission systems. The OPC method mutes the input signal by use of a polarization diversity loop arrangement. Since no spectral inefficiencies are introduced by the wavelength changes, phase conjugated idlers can be created throughout a broad frequency range. In nonlinear fibers, idle waves are generated by combining four waves with pump waves that are both out of band and orthogonally polarized. In order to mitigate the negative consequences of fiber nonlinearity due to mid-link spectrum inversion or multiple links, the OPC subsystem is used in transmission experiments spanning 760 km over dispersion-controlled fiber spans with lumped amplification by Improved Raman amplifiers. Using a 50 GHz channel spacing and eight 232 Gbps polarization division multiplexed (PDM) sixteen ary quadrature amplitude modulation (DP-16QAM) subchannels, the simulated results show a Q-factor improvement of up to 3.07 dB in mid OPC compared to 3.39 dB in multiple OPC without a backward R