Dongbi Bai

Abstract Optically pumped magnetometers (OPMs) enable high-resolution biomagnetic imaging, yet conventional single-beam designs are constrained by bulky, alignment-intensive polarization optics and susceptibility to laser-power noise. Here, we propose and demonstrate a compact, noise-suppressed OPM that uses a single planar liquid-crystal polarization grating (LCPG) functioning simultaneously as a high-efficiency polarization converter and a beam splitter.

The CW laser operation characteristics are shown in Fig. 2. In the plano-plano laser cavity, the laser threshold of absorbed pump power was about 0.94 W as shown in Fig. 2(a). At the common absorbed pump power of 6.12 W, the obtained maximum output powers were 1.94 and 2.58 W for output coupler transmission with 5% and 10%, respectively. Above the absorbed pump power of 5.3 W, there’s saturation effect for ceramic lasers both with T = 5% and 10%.