Linearization of an analog photonic link based on chirp modulation and fiber dispersion

A simple and new method to linearize an analog photonic link is proposed and demonstrated. A dual-electrode Mach-Zehnder modulator is single-electrode driven by a radio frequency (RF) signal, with the other electrode left empty, to achieve a chirp modulation. Then a dispersive single mode fiber (SMF) is followed to introduce different phase shifts on different optical sidebands. By properly selecting the working point of the modulator and the fiber length, the third-order intermodulation distortion can be suppressed. Experimental results show that an improvement of 15.7 dB in the spurious-free dynamic range and 4.5 dB in the link gain is achieved after linearization. The scheme is simple, low cost, and the low-loss SMF can also act as a transmission medium to deliver the RF signal efficiently to a remote location.