Exahertz-Per-Second Tuning Rate Laser

The fast-growing integrated ultrafast tuning rate semiconductor lasers have advanced the fields of light detection and ranging (LiDAR) and microwave photonics (MWP). Recent advances have demonstrated the exahertz-per-second fast tuning laser and the success of the LiDAR and MWP radar driven by tens of petahertz-per-second fast tuning lasers. However, a trade-off between the tuning rate and tuning range for the state-of-the-art fast-tuning lasers is still a must, which limits the detection resolution and speed of LiDAR or MWP radar systems. Here, we upset such a trade-off consideration in the same fast-tuning laser, reporting a laser with a record-high wavelength tuning rate of 4.817 exahertz per second at a continuous tuning range of over 20 gigahertz based on indium phosphide (InP) integrated circuits. Using the reported laser unit, we perform a proof-of-concept frequency-modulated continuous wave (FMCW) LiDAR with a high resolution of around 0.5 cm. Moreover, the demonstrated fast-tuning laser has the advantages of high linearity, small size, lightweight, and field deployment, providing a fast-tuning laser that surpasses existing ones for atomic physics, LiDAR, and MWP applications.