Improving the Accuracy and Resolution of Filter- and Frequency-to-Time Mapping-Based Time and Frequency Acquisition Methods by Broadening the Filter Bandwidth

Time-frequency transform based on frequency-to-time mapping and filtering

“…To further improve the frequency resolution of the timefrequency transform scheme, the SBS gain spectrum is manipulated. It is found that for each sweep chirp rate of the frequency-sweep optical signal, there is an optimal filter bandwidth that can assist the system to achieve the best frequency resolution [9]. For photonics-assisted time-frequency transform schemes based on FTTM and filtering, the sweep chirp rate of the frequency-sweep optical signal must be fast enough to ensure that the SUT in each sweep period can be seen as a stationary signal.…”

“…In this work, time-frequency transform systems reported recently by us, including STFT and wavelet-like transform, are introduced [7][8][9]. These systems avoid the use of dispersions and are implemented by adding a time dimension to the filter-and frequency-to-time mapping (FTTM)-based frequency measurement system.…”