A Novel Frequency Stabilization Method for External Cavity Diode Lasers Based on PZT Modulation

The method of frequency stabilization using injection current modulation can cause mode hopping in the laser. It also fails to fully utilize the benefits of PZT modulation for narrowing the laser linewidth. This study addresses the issue of laser frequency drift in external cavity semiconductor lasers, which is caused by fluctuations in temperature, injection current, and PZT voltage, adversely affecting measurement accuracy. To mitigate these problems, we propose a frequency stabilization method based on PZT modulation. By designing a PZT modulation demodulation device and optimizing the modulation parameters, we achieve a high stability frequency locking for the laser, with long-term stability reaching 1.12352 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-9</sup>@1000s. Experimental results demonstrate that our method is not only structurally simple and cost-effective, but it also satisfies the frequency requirements for various lasers, particularly those that have lower stability demands, such as the repumping laser and probe laser used in the field of quantum precision measurement.