Optical adaptive equalization of high-speed signals using time-domain optical Fourier transformation

This paper describes a new distortion-free optical transmission method that can eliminate any kind of linear perturbation including jitter, polarization-mode dispersion, and higher order dispersion as well as time-varying dispersion. This method uses transform-limited pulses and time-domain optical Fourier transformation (OFT). With this technique, particular attention is given to the spectral envelope profile of the transmitted signal, which is unchanged regardless of the type and magnitude of the linear perturbation in the transmission fiber. OFT converts the unchanged spectral profile into the time domain and allows to obtain undistorted original waveforms at the output. Experimental and analytical results to show the effectiveness of this method are presented, especially when the method is applied to high-speed signals up to 160 Gb/s, which are sensitive to both higher order and time-varying dispersions. This paper also describes a new all-optical time-domain Fourier transformation technique that uses an optical parabolic pulse. This technique is promising, with a view to improving the elimination of distortion at 160 Gb/s and above.