High-Accuracy Multi-Frequency Measurement Based on Stimulated Brillouin Scattering and Frequency-to-Time Mapping

We report a high-accuracy multi-frequency identification scheme based on stimulated Brillouin scattering (SBS) and frequency-to-time mapping (FTTM). In our scheme, a dual-drive Mach-Zehnder modulator (DDMZM) is driven by an unknown microwave signal to realize single-sideband (SSB) modulation. The optical carrier and the -1st optical sideband are processed as pump light to generate SBS in a 1-km highly nonlinear fiber (HNLF). A linearly chirped microwave (LCM) signal is fed to a phase modulator (PM) to generate a phase-modulated linearly chirped optical signal, which acts as the probe light in the SBS process. Actually, the narrow bandwidth SBS spectra are converted to microwave photonic filters (MPFs) after photodetection. In this way, the unknown frequency information of the microwave signal is mapped into the time domain and measured by calculating the time interval of the output electrical pulses. In the proof-of-concept experiment, single and multi-frequency microwave signals within a measurement range from L-band to Ku-band are successfully implemented with measurement errors of less than ±6 MHz.