Affordable dispersion mitigation method for the next generation RF-over-fiber optical channels.

Abstract

Next-generation analog radio frequency over fiber (RFoF) links will require dispersion compensation. Most dispersion compensation methods are based on additional optical elements. Therefore, these solutions may be inadequate for low-cost channels. In this work, we suggest a novel low-cost dispersion compensation solution for RFoF links. The method is based on two properties, which are common in these links: the modulation depth in analog RFoF links is lower than in digital links (and to avoid nonlinearities, it may be deliberately set to a small value), and the data are carried by a high-frequency carrier. It is shown that with these properties, the optical channel behaves approximately as a linear system. The distortion occurs in the linear domain and in the third-harmonic regime. Since the third-harmonic distortions are usually smaller than the back-to-back distortions, they are linear in the power domain. We therefore suggest using a simple low-cost electronic filter to compensate the dispersion distortions. The performance of this technique is presented both analytically and with a numerical simulation. These preliminary results are very encouraging and point to an inexpensive solution for next-generation RFoF links to the home.