FPGA-based automatic laser frequency stabilization system using the dynamic time warping algorithm

Achieving laser frequency stabilization is essential for high-precision applications in unmanned environments. This paper presents an FPGA-based automatic laser frequency stabilization system using the dynamic time warping (DTW) algorithm. We utilize DTW’s pattern recognition capability to directly identify spectrum signals during the locking process. Experiments were conducted using rubidium (Rb) polarization spectroscopy with an external cavity diode laser (ECDL) at 795 nm. Results indicate that the system can achieve automatic frequency locking and relocking within approximately 10 s, with a frequency stability of 6.09 × 10⁻¹⁰@1 s, 1.38 × 10⁻¹¹@1000 s. Compared with existing methods, this approach innovatively introduces an advanced algorithm, to the best of our knowledge, reducing development complexity and providing an effective solution for laser frequency stabilization in unmanned environments.