Four-Wavelength Mode-Locked DFB Laser Using Chirped Sampled Bragg Grating

Multi-wavelength mode-locked distributed feedback (DFB) lasers are among the simplest and most efficient devices for applications such as telecommunications and spectroscopy [1]. However, achieving stable mode-locked lasing across multiple wavelengths is challenging due to mode competition and temperature sensitivity [2]. Chirped conventional sampled Bragg gratings (C-SBGs) enhance wavelength stability, while reconstruction-equivalent chirp (REC) technology provides precise spectral control [3]. This work demonstrates the first DFB mode-locked laser incorporating chirped SBGs, achieving stable and simultaneous four-wavelength mode-locking, with promising potential for dense wavelength division multiplexing (DWDM) and advanced photonic technologies.