Coherent population trapping-based dual-wavelength modulation system for VCSEL

Coherent Population Trapping (CPT)-based atomic magnetometers, as a prominent subclass of alkali-metal vapor-cell magnetometers, achieve ultrahigh magnetic-field sensitivity by exploiting an extremely narrow-linewidth optical resonance. A highly stable laser source is a fundamental prerequisite for realizing such performance. Conventionally, when a Vertical-Cavity Surface-Emitting Laser (VCSEL) is employed as the light source in CPT-based atomic magnetometers, its drive electronics rely on discrete benchtop instruments, resulting in bulky systems with limited flexibility and portability. In this work, we present a compact CPT-based dual-wavelength modulation system for the VCSEL. The design integrates a microwave signal generator with excellent phase-noise performance and a high-precision direct current signal source, enabling the generation of a significantly more stable bichromatic optical field. This highly integrated solution addresses the critical demand for robust, lownoise laser sources in a wide range of applications, including quantum sensing and precision measurement, quantum information and computation, as well as fundamental physics research.