Eigenfrequency measurement of extended-cavity diode laser based on saturated absorption spectrum

A highly stable extended-cavity diode laser (ECDL) plays a crucial role in precision measurements. In this study, we propose a method based on the sound-solid coupling principle to measure the natural frequency of an extended-cavity diode laser. A frequency range of 0–2 kHz was employed to drive the ECDL, and the intrinsic frequency was obtained intuitively through the detuned saturation absorption spectrum. We compared the simulation and experimental results to validate the feasibility of the proposed method. Moreover, the structure of the laser was improved, and a new mechanical laser structure was designed and manufactured to suppress low-frequency resonance. The proposed method can help optimize the laser structure and improve the overall stability of the atom gyroscope.