Capacity estimates for optical transmission based on the nonlinear Fourier transform

Area of Science:

• Optical communications
• Information theory
• Nonlinear systems

Background:

• Fiber-optic communication systems transmit over 99% of global data traffic.
• Linear channel capacity is defined by Nyquist and Shannon, but fiber nonlinearity complicates optical link capacity.
• Nonlinearity is expected to cap the information-carrying capacity of fiber-optic systems.

Purpose of the Study:

• To determine the channel capacity of optical links, considering fiber nonlinearity.
• To establish a lower bound for capacity per symbol in nonlinear fiber-optic systems.
• To explore new methods for mastering nonlinear communication channels.

Main Methods:

• Utilizing the integrability of the master model.
• Applying the nonlinear Fourier transform.
• Estimating the lower bound on capacity per symbol.

Main Results:

• A lower bound on capacity per symbol was estimated at 10.7 bits per symbol.
• This estimation was achieved over a 500 GHz bandwidth and 2,000 km distance.
• Demonstrated a method to analyze nonlinear optical channels.

Conclusions:

• The study provides a method to estimate capacity in nonlinear fiber-optic systems.
• The findings suggest a significant information-carrying capacity even with nonlinearity.
• A paradigm shift in modulation, coding, and transmission techniques is needed for nonlinear channels.