通讯机构:
[Li, Gao-Xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词:
Fundamental processes;Light matter interactions;Photon correlations;Quantum optics;Resonance fluorescence;Spontaneous emission
摘要:
Multifold wave-particle quantum correlations are studied in strongly correlated three-photon emissions from the Mollow triplet via frequency engineering. The nonclassicality and the non-Gaussianity of the filtered field are discussed by correlating intensity signal and correlated balanced homodyne signals. Due to the non-Gaussian fluctuations in the Mollow triplet, new forms of the criterion of nonclassicality for non-Gaussian radiation are proposed by introducing intensity-dual quadrature correlation functions, which contain the information about strongly correlated three-photon emissions of the Mollow triplet. In addition, the time-dependent dynamics of non-Gaussian fluctuations of the filtered field is studied, which displays conspicuous asymmetry. Physically, the asymmetrical evolution of non-Gaussian fluctuations can be attributed to the different transition dynamics of the laser-dressed quantum emitter revealed by the past quantum state and conditional quantum state. Compared with the conventional three-photon intensity correlations that unilaterally reflect the particle properties of radiation, the multifold wave-particle correlation functions we proposed may convey more information about wave-particle duality of radiation, such as the quantum coherence of photon triplet and "which-path" in cascaded photon emissions in atomic systems. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
作者机构:
[Zhan, Huiping; Li, Gaoxiang; Tan, Huatang] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构:
[Tan, Huatang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要:
In this paper, we propose a feasible scheme for generating the Schrödinger-cat-like states of a macroscopic mechanical resonator in pulsed cavity optomechanics via photon detection. Starting with cooling the mechanical oscillator to its ground state, a red pulse and a blue pulse with different powers are simultaneously employed to dissipatively generate squeezed mechanical states. Subsequently, a second red pulse is utilized to achieve large-amplitude mechanical catlike states with high fidelities, conditioned on the multiphoton detection of cavity output and assisted by squeezing injection into the cavity. This combination effectively overcomes the difficulty that only a kitten can be produced by single-photon detection. Finally, after being stored in the resonator for a period of time during which thermal effect is analytically revealed, the mechanical quantum superpositions are mapped, with a third red pulse, to the cavity output field for state verification. Our scheme is generic and can also be used to produce other kinds of non-Gaussian mechanical states, such as optical-catalysis nonclassical states.
摘要:
The intensity-amplitude correlation functions for a driven cavity QED system with two non-identical atoms are investigated in this paper. With the support of conditional homodyne detection, one can detect the time-dependent intensity-amplitude correlation functions experimentally. We find time-asymmetry in this correlation when the driving field is tuned to be resonant with the two-photon excitation state, which brings non-Gaussian fluctuations. The physical origin of these phenomena is the distinction of the third-order moment based on complete-collapse and partial-collapse, which corresponds to the measuring sequence of the intensity and amplitude. Finally, we also examined the nonclassical features of the system, which always exhibits photon bunching. The squeezing occurs in the region of weak driving and disappears with the increase of driving strength. Hence, a new classical inequality based on the technique of homodyne cross-correlation measurement is introduced to determine the nonclassicality of the non-Gaussian system in the region of unsqueezing. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
通讯机构:
[Li, Gao-Xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词:
Doppler effect;Faraday effect;Laser beams;Laser pumping;Optical pumping;Two level systems
摘要:
We present a theoretical study of double-resonance alignment magnetometers using linearly polarized light, in which the effect of atomic high-order multipole moments is considered. Starting from the effective master equation of our system obtained by eliminating the excited state adiabatically, we derive the full evolution equations of the atomic multipole moments. The analytic solutions of resonance signals involving the four-order multipole moments effect are obtained by using the perturbation approach. We present that the four-order multipole moments effect is negligible in the weak laser field, and the results reduce to that obtained by a three-step approach. However, the role of four-order multipole moments coupled by two-order tensor moments is more significant with the increasing Rabi frequency of light, which cannot be ignored. Meanwhile, the analytic expressions of relaxation processes are also studied, which are a linear combination of the laser-induced equivalent relaxation rate Gamma(L) and the spin-exchange collision rate Gamma(g). The expected domain of validity of the three-step approach on light power is roughly given by Gamma(L) < 1/2 Gamma(g). In addition, the steady-state results of resonance signals are presented in a strong radio-frequency magnetic field; in that case, the physical mechanism of the splitting of resonance signals is discussed. These results are valid for arbitrary light power and for an arbitrarily oriented static magnetic field. (C) 2020 Optical Society of America
作者机构:
[Tan, Hua-Tang; Fang, Sen-Zhi; Wu, Qing-Lin; Zhu, Ling-Li; Li, Gao-Xiang] Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;[Jin, Rui-Bo] Wuhan Inst Technol, Sch Sci, Wuhan 430205, Peoples R China.
通讯机构:
[Wu, Qing-Lin] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词:
Optics;Precise measurement;Weak value
摘要:
The weak-value-amplification technique has been shown to be advantageous for precision metrology. Previous weak-value-based applications have used only a small fraction of data while discarding the rest during post-selection. Here we consider the use of the power-recycling technique to improve the sensitivity of an interferometric weak-value-based velocity measurement scheme. We discuss ways to realize this idea by introducing a power recycling mirror to make the Michelson interferometer a resonant optical cavity. In our analysis, the signal is well enhanced by the cavity and corresponding SNR is also improved although the temporal walk-off effect exits.
作者机构:
[Huang, Guang-ming; Li, Gao-xiang; Peng, Ze-an] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;[Yang, Guo-qing] Hangzhou Dianzi Univ, Coll Elect & Informat, Hangzhou 310018, Peoples R China.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要:
By constructing a quantum filtering system to synthesize the spectral and spatial properties of stimulated radiation, the directionality of spectrally correlated nonclassical properties of resonance fluorescence from a three-body quantum antenna is investigated. The quantum antenna consists of three two-level quantum emitters, two of which are identical and strongly driven by an external laser field to radiate the collective resonance fluorescence with three distinct spectral components. The collective stimulated radiation is shaped by the remaining auxiliary emitter via its spontaneous emission, which is assumed to be resonant with the higher-frequency spectral component of the two identical emitters. Due to the presence of the auxiliary emitter, highly directional nonclassicality of the spectral correlations can be generated, which is the consequence of the internal interference of the source and the spatial interference of the radiation field. The electric dipole-dipole interaction between the undriven emitter and the dressed two-body radiating source plays a crucial role in breaking the rotational symmetry of nonclassical signals, which is embodied by various photon correlation functions with a frequency-resolved version for different spectral combinations. By correlating the two opposite sidebands, the frequency-resolved intensity-intensity correlation functions can signal highly directional nonclassicality, and the frequency-resolved two-mode entanglement along a specific emission direction can be tested by the frequency-resolved anomalous correlation function. While the directional nonclassical correlations between the central-frequency and the three-body collective higher-frequency components can be identified through the frequency-resolved intensity-field correlation function. These various frequency-resolved correlation functions characterize the spatial asymmetry of nonclassical properties of the collective stimulated radiation from different perspectives, including the particle properties and the quantum coherences of the filtered photons. When the three-body collective higher-frequency sidebands are correlated with the central band and the lower-frequency sideband, respectively, the schemes of using the auxiliary undriven emitter to generate optimal nonclassical correlations with well-defined directions are discussed analytically. In addition, the results obtained from the three-body quantum antenna and a dressed two-body quantum antenna are compared.
期刊:
Journal of the Optical Society of America B,2020年37(2):574-578 ISSN:0740-3224
通讯作者:
Zhu, Yifu
作者机构:
[Yang, Guoqing; Liang, Shang-qing] Hangzhou Dianzi Univ, Coll Elect & Informat, Hangzhou 310018, Peoples R China.;[Huang, Guang-ming; Li, Gao-xiang; Geng, Xu-xing; Yu, Qi] Huazhong Normal Univ, Coll Phys, Wuhan 430079, Peoples R China.;[Zhu, Yifu] Florida Int Univ, Dept Phys, Miami, FL 33199 USA.
通讯机构:
[Zhu, Yifu] F;Florida Int Univ, Dept Phys, Miami, FL 33199 USA.
关键词:
Green lasers;Laser beams;Laser sources;Light matter interactions;Precision metrology;Semiconductor lasers
摘要:
We demonstrate a simple technique to lock the frequency of a laser to an atomic transition with a new technique of subnatural linewidth spectroscopy. The coupled rubidium system exhibits an enhanced absorption spectrum of the probe beam with a subnatural linewidth. Compared with other techniques with an additional laser, our scheme only utilizes a single laser, which will be locked. The observed spectroscopic linewidth is down to about 3.5 MHz. The laser frequency fluctuation is about 226 kHz after locking on. The demonstrated scheme offers a convenient and low-cost technique for laser frequency stabilization and related precision measurements. (C) 2020 Optical Society of America
作者机构:
[Zhang, He-bin; Li, Gao-xiang; Wu, Shao-ping] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要:
The frequency-resolved correlations of the fluorescence emitted by a four-level system in the J = 1/2 to J = 1/2 transition driven by a linearly polarized laser field are theoretically investigated. In the cross two-photon correlation of the pi and sigma(+) transitions, we show that VICs can induce the interference of time orderings between the two-photon paths with different dipole moments, which can serve as a good scheme to exhibit the effects of vacuum-induced coherences (VICs). An external magnetic field can cause frequency differences between two-photon paths with different time orderings. When the differences can be distinguished by detectors, the effects of VICs are destroyed and time asymmetry of the two-photon correlations appears due to the reveal of "which path" information. However, the which path information can be erased by tuning the filtering frequencies so the perfect interference effects of time orderings and time symmetry are restored.
作者机构:
[Huang, Guang-ming; Li, Gao-xiang; Zhao, Teng] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.;[Yan, Yan] Yangtze Univ, Sch Phys & Optoelect Engn, Jinzhou 434023, Peoples R China.;[Yang, Guo-qing] Hangzhou Dianzi Univ, Sch Elect & Informat, Hangzhou 310018, Zhejiang, Peoples R China.;[Zhu, Yifu] Florida Int Univ, Dept Phys, Miami, FL 33199 USA.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
摘要:
In a driven cavity QED system with two nonidentical qubits of different resonant frequencies, a multiphoton nonclassical state can be generated by single-photon and two-photon cavity-induced transparency (CIT). Due to the existence of the quasi-subradiant state, the parameter of radiance witness R can be greater than unity, which demonstrates that the cavity QED system is in the hyperradiance regime. In this hyperradiance regime, although the second-order correlation function g(2)(0) is greater than unity, the photon statistics still exhibits the higher-order sub-Poissonian distribution. Because the single-photon and two-photon processes are suppressed by CIT-like effects, the three-photon process is enhanced, which leads to Klyshko's criterion Kn<1 for n>2, indicating the appearance of multiphoton nonclassicality. Based on this principle, we propose a scheme for preparing multiphoton nonclassical light with a three-photon probability of 10−4, which is feasible for experiment.
作者机构:
[Li, Gao-xiang; Zhou, Ben-yuan] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.;[Zhou, Ben-yuan] Air Force Early Warning Acad, Basic Course Dept, Wuhan 430019, Hubei, Peoples R China.;[Yang, Guo-qing] Hangzhou Dianzi Univ, Sch Elect & Informat, Hangzhou 310018, Zhejiang, Peoples R China.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
摘要:
We propose and demonstrate a standard form of Einstein-Podolsky-Rosen (EPR) steering for an arbitrary bipartite Gaussian state under which a simple EPR steering criterion for two-photon correlation can be achieved. In terms of a beam splitter preparing three different steerable states, we further test that the simplified criterion is reliable and efficient when it is used to determine whether an arbitrary bipartite Gaussian state is steerable or not. Based on the same theoretical framework, the standard form and criterion of entanglement are reconstructed and discussed. Furthermore, it is found that EPR steering requires stronger two-photon correlation than entanglement, while its direction is strictly dependent on the mean photon number of two light modes. Moreover, the inherent asymmetric feature can be intuitively embodied in the corresponding criteria, and the essential difference and inherent relation between two standard forms is revealed. We hope the present results could be helpful for potential applications in quantum information processing.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
摘要:
We investigate the absorption spectra for the Fg=1→Fe=0 transition of the D2 line of Rb87 excited by a linearly polarized light in the presence of a transverse magnetic field (TMF) in different directions. Using the theoretical methods in quantum optics, we obtain the analytical expressions for the atomic density-matrix elements and the absorption spectrum. We analyze the splitting proportional to the magnitude of the TMF in the coherent population trapping absorption spectrum and explain its physical origin. Then, the sensitivity of the resonance signal to the phase (in our case, to the angle between the TMF and the light polarization) is investigated. We show and explain the splitting of the bright resonance and find the simple dependence of the separation of this splitting on the magnitude and the direction of the TMF. Therefore, this system may provide a possible method for the measurement of the magnetic field vector. In addition, we study the coherence of the system based on an observable coherence measure, namely, robustness of coherence (ROC). We find that in the case where the absorption signal becomes difficult to detect, the change of the ROC spectrum becomes more obvious and the extreme points are well maintained. Therefore, this may provide a scheme for the measurement of the magnetic field which is complementary to that based on the absorption signal of the laser.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
摘要:
Frequency-resolved quantum correlation of resonance fluorescence is investigated in a two-atom radiating system. In this quantum radiating system, only one atom is driven by a laser field, and the spontaneous transition of the undriven atom resonates with one of the Rabi sidebands of the driven atom. A single-mode empty cavity is applied to serve as a Lorentzian filter to output the superbunched fluorescent photon pairs when its frequency is tuned to halfway between the central peak and one of the side peaks. In the case of large filter width, two-photon correlation signal and its physical correspondence can be bridged analytically in our approach. It reveals that this superbunching effect turns out to be the constructive quantum interference between a pair of coupled two-photon cascaded transitions. Ulteriorly, it is the consequence of the modulations of the unfiltered dressed-state transition amplitudes by the filter. Our analytical formalism also shows that, although the dipole-dipole interaction is usually weak, the interatomic coherence caused by this weak perturbation can also play a crucial role in breaking through the superbunching limit obtained from a single two-level atom in the same parameter regime. In addition to being a treasurable quantum pump to probe into the target quantum system, it is also found in our investigation that this superbunched fluorescence can serve as a promising quantum response in detecting this weak perturbation in the interior of the quantum source. A general case is also considered when the two-atom radiating system is monitored by two filter-detector monitoring systems. It is found that this filtered strong quantum correlation can be maintained even though the two photons are spatially separated.
摘要:
Within the framework of macroscopic quantum electrodynamics, we investigate both the radiation force and the potential of Casimir-Polder type acting on an excited cold two-level atom in a cavity made of left-handed materials and topological insulators. As the time-reversal symmetry is broken on the surface of the topological insulators, the spontaneous emission of the atom placed near the focus point(s) exhibits anisotropic properties. While the potential wells are normally shallow for topological trivial dielectric, they may be amplified in the presence of topological magnetoelectric effect. We find that when there exists only one focus point in the cavity, it is possible to boost the forces or the potential wells by up to one order of magnitude. Meanwhile, the lifetime of the atom could be prolonged owing to the focus effect of the left-handed materials, where the emitted photons can trace back to the atom and reabsorbed by itself. Our results indicate the possibility in forming long-lived potential wells, which may have potential applications in trapping and guiding cold atoms far away from the surface. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
期刊:
Journal of the Optical Society of America B,2019年36(6):1700-1705 ISSN:0740-3224
通讯作者:
Li, Gao-Xiang
作者机构:
[Yan, Yan] Yangtze Univ, Inst Quantum Opt & Informat Photon, Sch Phys & Optoelect Engn, Jingzhou 434023, Peoples R China.;[Li, Gao-Xiang; Huang, Ge] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.;[Zhou, Zhi-Dong] Cent China Normal Univ, Middle Sch 1, Wuhan 430223, Hubei, Peoples R China.
通讯机构:
[Li, Gao-Xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
关键词:
Cavity quantum electrodynamics;Laser pumping;Nonlinear optical crystals;Quantum computation;Quantum information;Squeezed states
摘要:
Four-mode continuous-variable (CV) cluster states are an important and necessary resource in continuous-variable quantum computation. In this paper, we present a simple and efficient scheme to realize an unequally weighted four-mode square CV cluster state using atomic ensembles driven by seven strong classical laser fields. The scheme requires just a single selection of the appropriate squeezing parameters and pump laser parameters. With the unique squeezing operator and a new unitary transformation, we show that seven laser fields drive four atomic ensembles into a stationary four-mode squeezed vacuum state via the cavity dissipation.
关键词:
Light matter interactions;Quantum dots;Quantum optics;Resonance enhancement;Resonance fluorescence;Squeezed states
摘要:
We investigate the radiation properties of a driven exciton-biexciton structure quantum dot placed close to a graphene sheet. The study of the Purcell factor then demonstrates the tunability of light-matter coupling, which in turn provides the possibility to control the steady-state populations. As the result, dipole transitions can be selectively enhanced and asymmetry in the resonance fluorescence can be observed. Meanwhile, both quadratures can exhibit two-mode squeezing at the Rabi sideband frequencies. A further study shows that although the increase in the environment temperature has a destructive influence on the population imbalance, squeezing occurs even at room temperature. Due to the flexibility in controlling the resonance fluorescence spectrum and producing two-mode squeezed states, our proposal would have potential applications in quantum information and other quantum research fields.
作者机构:
[Wei, Yang-hua; Yang, Guoqing; Li, Gao-xiang; Gu, Wen-ju] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.;[Gu, Wen-ju] Yangtze Univ, Sch Phys & Optoelect Engn, Jinzhou 434023, Peoples R China.;[Yang, Guoqing] Hangzhou Dianzi Univ, Sch Elect & Informat, Hangzhou 310018, Zhejiang, Peoples R China.;[Zhu, Yifu] Florida Int Univ, Dept Phys, Miami, FL 33199 USA.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
摘要:
Coherent perfect absorption (CPA) is investigated in the quantum nonlinear regime of cavity quantum electrodynamics (CQED), in which a single two-level atom couples to a single-mode cavity weakly driven by two identical laser fields. In the strong-coupling regime and due to the photon blockade effect, the weakly driven CQED system can be described as a quantum system with three polariton states. CPA is achieved at a critical input field strength when the frequency of the input fields matches the polariton transition frequency. In the quantum nonlinear regime, the incoherent dissipation processes such as atomic and photon decays place a lower bound for the purity of the intracavity quantum field. Our results show that under the CPA condition, the intracavity field always exhibits the quadrature squeezing property manifested by the quantum nonlinearity, and the outgoing photon flux displays the super-Poissonian distribution.
作者机构:
[Ren, Wenguan; Shi, Yufeng; Yang, Xiaoping; Zhao, Xiaoli; Shao, Sipei] Shandong Inst Space Elect Technol, Yantai 264000, Peoples R China.;[Yang, Guoqing] Hangzhou Dianzi Univ, Sch Elect & Informat, Hangzhou 310018, Zhejiang, Peoples R China.;[Li, Gaoxiang] Huazhong Normal Univ, Coll Phys, Wuhan 430079, Hubei, Peoples R China.
会议名称:
Conference on Precision Electromagnetic Measurements (CPEM)
会议时间:
JUL 08-13, 2018
会议地点:
Paris, FRANCE
会议主办单位:
[Zhao, Xiaoli;Ren, Wenguan;Yang, Xiaoping;Shi, Yufeng;Shao, Sipei] Shandong Inst Space Elect Technol, Yantai 264000, Peoples R China.^[Yang, Guoqing] Hangzhou Dianzi Univ, Sch Elect & Informat, Hangzhou 310018, Zhejiang, Peoples R China.^[Li, Gaoxiang] Huazhong Normal Univ, Coll Phys, Wuhan 430079, Hubei, Peoples R China.
关键词:
high-precision;interference magnetic field;magnetometer;optically induced fictitious magnetic field;wideband magnetometer
摘要:
We propose a wideband magnetometer based on the classical M-x method realized with the multiple fictitious magnetic fields by applying a spatial light modulator and a microlens array. We give a brief theoretical description of the optically induced fictitious magnetic field and introduce the experimental setup of this magnetometer. Compared with the traditional magnetometers, the band of this magnetometer is user-defined and can cover up MHz order of magnitude, which is conducive to measure the interference magnetic field with wide frequency band.
通讯机构:
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
摘要:
Frequency-resolved correlation (FRC) is investigated in fluorescent emission radiated from a Λ-type atomic system by employing weak coupling regime between quantum emitter and cavities, in which each cavity substituting a Lorentzian filter is assumed to pass through only one fluorescent photon at a time so that the analytical discussions for time orderings can be carried out in a truncated Hilbert space with single-excitation state for each cavity mode. In the limit of bad cavity (large passband width of filter) and short delay, the conditional time ordering amplitudes are introduced with the help of conditioned dressed atom-photon states prepared by preselection to probe into the effect of preferential screening for time orderings of filter-detector systems. Meanwhile, the past quantum state formalism is also applied in FRC to further excavate their collective monitoring effect. Based on the obtained two-mode correlation signals, it is found that, in nonresonant two-photon cascaded processes, bunching and antibunching can appear in two opposite detection orderings, respectively, and can be switched. The physical origin is explored that the two different transition amplitudes of emitted photons from a common spectral band of resonance fluorescence are responsible for opposite time orderings, thus, the imbalance between two complementary time orderings can be enhanced, which is impossible to achieve in resonance fluorescence of two-level atoms. This mechanism is embodied in the conditional time ordering amplitudes produced by this detection theory of cavity modes.
作者机构:
[Yang, Guoqing; Liang, Shang-qing] Hangzhou Dianzi Univ, Coll Elect & Informat, Hangzhou 310018, Zhejiang, Peoples R China.;[Huang, Guang-ming; Zhang, He-bin; Yang, Guoqing; Li, Gao-xiang; Mao, Jing-tao; Geng, Xu-xing] Huazhong Normal Univ, Coll Phys, Wuhan 430079, Hubei, Peoples R China.;[Zhu, Yifu] Florida Int Univ, Dept Phys, Miami, FL 33199 USA.
通讯机构:
[Yang, Guoqing] H;Hangzhou Dianzi Univ, Coll Elect & Informat, Hangzhou 310018, Zhejiang, Peoples R China.;Huazhong Normal Univ, Coll Phys, Wuhan 430079, Hubei, Peoples R China.
关键词:
High power lasers;Magnetic fields;Medical imaging;Precision metrology;Resonance;Spontaneous emission
摘要:
The radiofrequency-optical double magnetic resonance in cesium atoms filled in a vapor cell is investigated experimentally. One resonant signal involving spin-exchange collisions is observed in the MZ type magnetic resonance spectrum. We solve Liouville equations describing the dynamics of the system and analyze the role of the spin-exchange collisions in the atomic population distributions under resonant conditions. The theoretical calculations agree very well with the experimental results. In contrast with the normal magnetic resonance, the collision induced magnetic resonance exhibits the interesting saturation effect: both the signal amplitude and the signal linewidth are nearly constant when the laser intensity is above a moderate threshold value, which can be useful for precision measurements of the geomagnetic field.