An Ultrafast Wavelength-swept REC-DFB Laser Based on the Instantaneous Injection Current

An ultrafast wavelength-swept distributed feedback (DFB) semiconductor laser based on the reconstruction-equivalent-chirp (REC) technique via instantaneous injection current modulation is demonstrated. The REC technique can simplify the DFB fabrication process and maintain good single-mode operation. The driving circuit equipped with FPGA can generate a precise pulse current by controlling the n-metal-oxide-semiconductor field effect transistor (n-MOSFET). By changing the pulse voltage or pulse width of the laser injected current, a wide and fast wavelength-tuning can be realized. Specifically, we achieve a continuous wavelength-swept range of 9.27 nm within 5 μs. This method is of great significance for the future development of optical sensing systems.