A5023870536- Atomic and Subatomic Physics Research
- Advanced MRI Techniques and Applications
- Quantum optics and atomic interactions
- Semiconductor Lasers and Optical Devices
- Non-Invasive Vital Sign Monitoring
- Photonic and Optical Devices
- Advanced Frequency and Time Standards
- Glass properties and applications
- Functional Brain Connectivity Studies
- Magneto-Optical Properties and Applications
- Advanced Fiber Laser Technologies
- Earthquake Detection and Analysis
- Advanced NMR Techniques and Applications
Beihang University
2020-2023
We propose a three-axis closed-loop optically pumped magnetometer with high sensitivity. The has sensitivity of approximately 30 fT/Hz1/2 using two orthogonal laser beams for pumping and probing the alkali metal atoms. In mode, dynamic range is improved from ±5 nT to ±150 nT. bandwidth increased about 100 Hz over 2 kHz 10 modulation fields in x- y-axes another 6 field along z-axis. Compared single-axis or dual-axis magnetometers, proposed not only provides direction magnitude magnetic but...
In recent years, significant developments have occurred in the field of optically pumped magnetometers (OPMs), which are widely used biomagnetic measurements. this study, we propose a temperature optimization model for single-beam miniaturized atomic magnetometer. Based on model, find that there is an optimal operating each individual vapor cell, under OPM achieves performance. We construct zero-field modulation to prove model. The sensitivity magnetometer reaches 18 fT/Hz <sup...
This paper investigates the performance optimization of optically pumped magnetometers under zero-field parametric modulation. Based on analytical solutions Bloch equation, both longitudinal and transverse modulations are studied experimentally. To estimate nonuniform polarization distribution alkali-metal atoms in vapor cell, an average pumping rate model is proposed. Furthermore, accuracy this measurement relaxation verified via agreement between experimental theoretical values. The...
Compact atomic magnetometer has become an important approach for noise measurement of magnetic shielding systems as well biomagnetic measurement. In this study, we propose a novel method that enables time-shard triaxial field measurements in near-zero through compact high-performance with femtotesla sensitivity. With pump–probe orthogonal configuration, the can be operated without optical and modulation. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML"...
We propose non-magnetic heating film based on indium tin oxide (ITO) and apply it in a miniaturized spin exchange relaxation free (SERF) gradient magnetometer. To achieve ultrahigh sensitivity, alkali metal atoms inside the vapor cell of magnetometer require an elevated temperature field that is stable uniform. ITO transparent electrically conductive material which suitable for such application can be used as resistance wire to form film. A structure composed insulation layer sandwiched...
In this study, we propose an approach for the simultaneous measurement of triaxial magnetic fields using a single-beam zero-field optically pumped atomic magnetometer, in which rotational high-frequency ( ω 1 ) and another 2 modulated field are applied along transverse directions longitudinal direction, respectively. Theoretical analysis, numerical simulation, experiments conducted to demonstrate method. Experimental sensitivities 18 fT/Hz 1/2 two 140 direction simultaneously achieved. On...
Abstract For optically pumped atomic magnetometers, the attenuation of pumping light through alkali-metal vapor due to absorption is related number density atoms. In this study, we propose an in-situ measurement and control method based on in temperature range 60 °C–160 °C, which a much wider than considered previous reports. A absorption-density model proposed accurately describe relationship between transmittance density. The influence static oscillating magnetic fields also analyzed....
Traditional practice of suppressing low-frequency noise in atomic magnetometers is mainly through the application magnetic field modulation, while fields this kind introduce extra transverse relaxation, which results a decrease sensitivity. In study, novel method measuring relaxation rate induced by spin-destruction, wall collisions and modulation proposed. The optical pumping model studied both optical-thin optical-thick vapor cell analysis total thus can be separated from analyzing depth....
Atomic magnetometers are widely acknowledged as one of the most sensitive devices for magnetic field measurement. Our study presents a novel method that enables bandwidth expansion single-beam in spin-exchange relaxation-free regime. This bases on increasing modulation amplitude combining with negative feedback proportional gain. Through our method, magnetometer’s total relaxation rate is moderately increased by elevating and frequency, correspondingly, detection experiences dramatic...
Three-axis atomic magnetometers have an excellent advantage for determining the complete vector information of a magnetic field to be measured. However, crosstalk effect, which leads error output on one axis owing other axes, can reduce measurement accuracy. In this study, we propose effective suppression method effect in three-axis magnetometer. First, investigated and analyzed main factors that introduce effect. Based this, modulation parameters were optimized improve scale factors,...
Optically pumped magnetometers (OPMs) have developed rapidly in the bio-magnetic measurement field, which requires lasers with stable frequency and intensity for high sensitivity. Herein we stabilize a vertical-cavity surface-emitting laser (VCSEL) without any additional setup except parts of an OPM. The linewidth absorption spectrum as reference is broadened to 40 GHz owing pressure broadening. To enhance performance, VCSEL injection current temperature are tuned simultaneously using...
A new design of compact zero-field atomic gradiometer was proposed and integrated using alkali vapor cell customized optical components. This used two parallel elliptically polarized lights, whose output intensity measured to perform gradient magnetic field detection, respectively. To improve the gradiometer's sensitivity operated in spin-exchange relaxation-free (SERF) regime. For study, placed a person-sized four-layer μ-metal shielding. With shield closed up, each channel near 34 fT/ √...
Recent developments in the exploration of atomic spin instrumentation have enabled magnetometer to become most effective detector magnetic fields. The stability temperature alkali vapor cells is an important factor for ensuring measurement accuracy magnetometers. cell usually heated 80°C ∼ 190°C. During heating process, although system reaches a steady state, inside metal will still fluctuate, which affect device measurement. In this paper, K were simulated and analyzed by using theory...