Quantum Optical Magnetometry (QOM) is an improtant branch of quantum precision measurements. With the development of modern science and technology, QOM has already been used in fields like biomedicine, geophysics, space exploration and military affairs. QOM is of great significance considering its contributions to human health, development of society, technological advancements and defense construction. The devices or instruments for magnetometry are called magnetometers and quantum magnetometers are the apparatus based on the principles of quantum physics and techniques of experimental atomic physics. Among all the quantum magnetometers, optically pumped atomic magnetometers are the most mature ones with widest applications in both scientific research and practical production.
CREAM Group has been doing both theoretical and experimental research on light-matter interactions for years and accumulated rich experience and fruitful results. According to the anterior foundations, CREAM Group began to develop the research of optically pumped atomic magnetometers based on helium and alkali metal atoms at the beginning of the "12th five-year" plan. In recent 5 years, by breaking through and mastering key techniques of laser sources, atomic sensor fabrication and detecting circuits for magnetic resonance signals, CREAM Group has developed the laser pumped helium magnetometer successfully.
Recently, by exploring physical mechanisms of new-type magnetometers and upgrading key techniques, CREAM Group has improved the performance of magnetometers including the key index – sensitivity. Besides, CREAM Group has developed cooperation both in China and abroad to participate in the global work of constructing the testing platforms and exploring the applications in basic physics for magnetometers, which might brought richer research achievements in the future.
 Teng Wu, Xiang Peng, Zaisheng Lin, and Hong Guo, “A dead-zone free 4He atomic magnetometer with intensity-modulated linearly polarized light and a liquid crystal polarization rotator,” Rev. Sci. Instrm. 86, 103105 (2015).
 Teng Wu, Xiang Peng, and Hong Guo, “Light shift manipulation and suppression in a double pass optical-magnetic double resonance system,” Laser Phys. 24, 106001 (2014).
 Wei Gong, Xiang Peng, Wenhao Li, and Hong Guo, “Frequency stabilization of a 1083 nm fiber laser to 4He transition lines with optical heterodyne saturation spectroscopies,” Rev. Sci. Instrum. 85 (7), 073103 (2014).