Wideband Adaptive Feedforward Photonic Link

We present the first demonstration of an adaptive wideband radio-frequency (RF) photonic link architecture suitable for high-dynamic-range microwave signal fiber optic transport. The architecture incorporates feedforward (FF) linearization to correct the electrical-to-optical (E/O) conversion nonlinearity as well as optimized control loops that enable the system performance to be maintained in real time during changing operating conditions. Third-order distortion suppression of greater than 25 dB has been demonstrated over the input frequency range of 2 GHz to >17 GHz. Under manual control of the wideband FF linearized photonic link, a spur-free dynamic range (SFDR) in excess of 120 dB-Hz ^2/3 is demonstrated, while an SFDR of >116 dB-Hz^2/3 is achieved with adaptive control. We present experimental results of a fully automated wideband FF photonic link and also discuss the potential for the technique.