Fiber optic loop

The fiber optic loop will be able to simulate systems spanning tens of thousands of kilometers. The data encoded optical pulse stream is sent to a fiber optic loop typically ranging from 100km to 400km, and any number is cycled from several loops to up to 100 loops. After a certain number of loops, the optical signal is coupled out and analyzed. Several transmission parameters can be measured, such as eye diagram, q-factor, pulse shape, spectrum, chirp, or bit error rate (BER), to understand how signals degrade due to fiber dispersion, loss, and nonlinearity, or how signals improve through dispersion compensation, dispersion management, or online transmission control.