High-accuracy CPT-based atomic magnetometer with compact optical and electronic architecture

We present a compact CPT-based atomic magnetometer utilizing a directly modulated VCSEL and phase-sensitive detection. The device achieves a static magnetic field measurement accuracy of 20 pT (1<i>σ</i>) with directional consistency exceeding 99.6%. Calibration using saddle and solenoidal coils yields a linear response with coil coefficients of 708.4 nT/mA and 2466.3 nT/mA, respectively, closely matching an optically pumped Mx-type magnetometer. The results validate the feasibility of portable, high-sensitivity CPT magnetometers for real-time vector magnetic field sensing.