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Lamp-based Optically Pumped Cesium Magnetometer
The current position:Research < Lamp-based Optically Pumped Cesium Magnetometer
    The extremely important information hidden in the extremely weak magnetic field and its small fluctuations pushes us to explore precision measurement of these physical quantities. Lamp-based optically pumped Cesium magnetometer (CsOPM) is a kind of quantum magnetometers for those applications. It was widely used in aero magnet measurement, ocean monitor, geography exploration, earthquake forecast, health care and sanitation and so on. The future and application is attracting. Comparing with other magnetometers, CsOPM possesses many obvious advantages—good sensitivity in the level of pT/Hz1/2, better applicability in airborne surveys and appropriate property of Cs’ single strong resonance than the traditional magnetometer and can be installed on an air plane. Principle: CsOPM utilizes the Zeeman Effect. The splitting of an energy level is approximately proportional to the intensity of the static magnetic field. If we can measure the splitting precisely, then we can precisely deduce the amplitude of the magnetic field. Structure: As shown in Fig.1, light from an electrodeless Cs vapor lamp is circularly polarized and passes through a Cs vapor glass cell. It causes the optically pumped process. In an outer static magnetic field B, the angular momentum spins around B in Larmor frequency fL. When the RF frequency is fL, the Cs vapor absorbs most photons and the cell becomes dim. With the help of photo-detection and lock-in technique, we can lock the system. After we measure the Larmor frequency and use the equation of γB=fL(γ is gyromagnetic ratio), we can get the amplitude of the magnetic field.
Fig.1 CsOPM (passive type)
    Results at present We have developed an experimental system and already observed the Zeeman transition signal shown in Fig.2. Now we are undertaking the work of enhancing the Signal-to Noise ratio and designing the servo locking system.
Fig.2 Lamp pumped cesium Zeeman spectrum