1 长春职业技术学院, 吉林长春 130033
2 中国科学院长春光学精密机械与物理研究所, 中国科学院天基动态快速光学成像技术重点实验室, 吉林长春 130033
3 中国人民解放军63850部队, 吉林白城 137001
红外系统的作用距离参数是表征红外系统成像性能的重要指标。目前, 红外系统作用距离的计算方法有多种, 但都有其各自的适用性和局限性, 因此需要考虑不同条件下多种因素对作用距离的影响。本文基于探测能量、基于噪声等效温差(NETD)的和基于对比度的 3种点目标探测的作用距离模型, 发现在不同条件下应用的局限性。当观测目标为人时, 基于 NETD的模型计算作用距离为 8.74 km, 与外场实验数据更为接近。而当观测目标为飞机时, 基于能量的模型计算作用距离为32.04 km, 与外场实验数据更为接近。结果表明, 针对不同特征的目标, 选取适当的作用距离计算方法有助于提高系统作用距离估算的准确度。
红外系统 作用距离 点目标 对比度 infrared system operating range point target NETD NETD, contrast
红外与激光工程
2020, 49(5): 20190413
Author Affiliations
Abstract
1 College of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China
2 College of Physics, Huazhong Normal University, Wuhan 430079, China
A DC current sensor based on an optically pumped atomic magnetometer is proposed. It has a high linearity in a wide operation range, since the magnetometer measures the absolute magnitude of the magnetic field produced by the current to be measured. The current sensor exhibits a high accuracy with a non-moment solenoid and magnetic shielding to suppress the influence from the environment. The absolute error of the measured current is below 0.08 mA when the range is from 7.5 mA to 750 mA. The relative error is 5.54 × 10?5 at 750 mA.
current sensor atomic magnetometer high accuracy Chinese Optics Letters
2020, 18(3): 031202
Author Affiliations
Abstract
1 State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou 310027, China
2 College of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China
3 Key Laboratory of RF Circuit & System (Hangzhou Dianzi University), Ministry of Education, Hangzhou 310018,China
Multi-photon parametric magnetic resonance in a miniature vapor cell is demonstrated. Much more multi-photon magnetic resonance can be observed when the radio frequency field becomes stronger. The linewidth of the n photons magnetic resonance equals that of the first-order resonance divided by n, which means that the uncertainty of the magnetic sublevel is reduced by the factor n. The signal-to-noise ratio can be improved when the low-frequency multi-photon resonance takes place, which finds a possible application in precision magnetic field measurement.
020.7490 Zeeman effect 270.4180 Multiphoton processes Chinese Optics Letters
2017, 15(7): 070201
Author Affiliations
Abstract
We experimentally demonstrate a simple modulation-free scheme for offset locking the frequency of a laser using buffer gas-induced resonance. Our scheme excludes the limitation of low diffraction efficiency and laser input intensity when an acousto-optic modulator is applied to shift the laser frequency from the resonance. We show the stabilization of a strong 795-nm laser detuned up to 550 MHz from the 87Rb 5S1/2F=2->5P1/2 F'=2 transition. The locking range can be modified by controlling the buffer gas pressure. A laser line width of 2 MHz is achieved over 10 min.
020.3690 Line shapes and shifts 140.2020 Diode lasers 270.1670 Coherent optical effects 300.6260 Spectroscopy, diode lasers 300.6420 Spectroscopy, nonlinear Chinese Optics Letters
2013, 11(10): 100201
Author Affiliations
Abstract
1 State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
2 Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China
The interaction between polychromatic fields and atoms is an important subject in quantum optics. Frequency locking for small frequency interval multi-field is usually required in some experiments. In this letter, we experimentally demonstrate a holistic scheme for bichromatic laser frequency stabilization. Compared with traditional saturation absorption methods and complicated frequency shift schemes, offset locking for bichromatic fields is simply achieved using polarization spectroscopy and Doppler effect. Frequency locking with a wide-range asymmetry of the detuning is also shown. Our scheme makes laser spectroscopy experiments with polychromatic fields more convenient.
光谱 稳频 多普勒效应 140.3425 Laser stabilization 300.3700 Linewidth Chinese Optics Letters
2010, 8(11): 1095
Author Affiliations
Abstract
State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071
A simple method based on Sagnac interferometric spectroscopy (SIS) is applied for frequency stabilization of diode lasers. Sagnac interferometric spectra of rubidium vapor are investigated both theoretically and experimentally. The interference signal at the output of the Sagnac interferometer displays a sharp dispersion feature near the atomic resonance. This dispersion curve is used as the feedback error signal to stabilize the laser frequency. Linewidth of a diode laser is stabilized down to 1 MHz by this modulation-free method.
激光稳频 萨格奈克光谱 300.3700 Linewidth 300.0300 Spectroscopy 140.0140 Lasers and laser optics Chinese Optics Letters
2008, 6(4): 307
