Fig. 1. Schematic diagram of NMR measurement based on LPAS (ST: sample transmission; MS: magnetic shield; LPAS: laser-pumped atomic sensors). (a) Enhanced polarization of the sample under investigation; (b) the sample after enhanced polarization is transferred to the LPAS measurement area for NMR measurement

Fig. 2. Schematic diagram of LPAS (BD: balanced photodetector; PBS: polarizing beam splitter)

Fig. 3. Schematic diagram of an NMOR LPAS

Fig. 4. Zero-field NMR spectrum of natural isotope abundance ¹⁵N-pyridine with SABRE polarization measured by commercial LPAS, where the SABRE reaction scheme is shown in the inset^[49]

Fig. 5. Detailed structure of the high-frequency multiplets in the ZF-TOCSY spectrum of 1-¹³C ethanol^[64]

Fig. 6. Magnetic shieldless 3D ultralow field MRI of digital model^[89]. (a) FT-LPAS 3D ultralow field MRI measuring device; (b) geometry of the digital model; (c) digital model 3D imaging slices, the direction is from H plane to K plane of the model

Table 1. Advances in LPAS