Intrinsic Spectrum Analysis of Laser Dynamics Based on Fractional Fourier Transform

The intrinsic spectrum that results from the coupling of spontaneous emission in a laser cavity can determine energy concentration and coherence lasers, which is crucial for optical high-precision measurements. To date, it has been difficult to analyze high-speed dynamics processes, especially under condition fast wavelength sweeping. In this work, new method proposed with decomposition into series chirp-frequency signals, realized by fractional Fourier transform (FRFT) coherently reconstructed waveform. understanding distribution lasers contributes accurate characterization dynamic parameters time-frequency domain. proof-of-concept experiment, process commercial wavelength-swept tested different wavelength-scanning speeds, most suitable measurement time window width required narrowest FRFT-based also explored. analysis will promote benefit precision applications.