Dynamic Range Improvement of a Microwave Photonic Link Based on Brillouin Processing
A novel method to improve the spurious free dynamic range (SFDR) of a microwave photonic link based on stimulated Brillouin scattering (SBS) processing is proposed and experimentally demonstrated. In the proposed system, an optical single sideband with suppressed carrier (SSB SC) signal is generated using a dual parallel Mach Zehnder modulator (MZM) by biasing its two sub MZMs at minimum transmission point and the parent MZM at quadrature transmission point. In order to generate SBS, the SSB SC signal is amplified and injected into a length of dispersion shifted fiber where the MPL's double sideband optical signals are transmitted. Due to the SBS effect, a phase shift is induced to MPL's optical carrier band, and hence, the third order intermodulation distortion (IMD3) components originated from two different sources can cancel each other. Experimental results show that the SFDR of the link is improved by 10.3 dB, and the IMD3 is reduced by more than 23 dB.
IEEE Photonics Technology Letters