Short-Time Fourier Transform Based on Stimulated Brillouin Scattering

In this paper, all-optical short-time Fourier transform (STFT) based on stimulated Brillouin scattering (SBS) is proposed and further used for real-time time-frequency analysis of different radio frequency (RF) signals. the STFT scheme, SBS not only provides a band-pass filter implementing window function in conjunction with periodic frequency-sweep optical signal but also obtains domain information time windows through generated waveform via frequency-to-time mapping (FTTM). A then modulated at Mach–Zehnder modulator by electrical under test (SUT). During sweep periods, fixed gain functions as bandpass to select specific range spectrum, which equivalent applying sliding corresponding section temporal help signal. At same time, after selectively amplified converted back domain, implements FTTM, can be utilized obtain waveforms FTTM. The formed spliced analyze relationship SUT real-time. We demonstrate concept experimentally. STFTs variety RF signals are carried out 12-GHz bandwidth limited equipment, dynamic resolution better than 60 MHz.