期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
Effectively modulating spatial vortex four-wave mixing in a diamond atomic system
1
作者 巴诺 姜明奇 +4 位作者 费金友 王丹 蒋海林 王磊 王海华 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期473-478,共6页
Due to the spatial characteristics of orbital angular momentum,vortex fields can be applied in the fields of quantum storage and quantum information.We study the realization of spatially modulated vortex fields based ... Due to the spatial characteristics of orbital angular momentum,vortex fields can be applied in the fields of quantum storage and quantum information.We study the realization of spatially modulated vortex fields based on four-wave mixing in a four-level atomic system with a diamond structure.The intensity and spiral phase of the vortex field are effectively transferred to the generated four-wave mixing field.By changing the detuning of the probe field,the phase and intensity of the generated vertex four-wave mixing field can be changed.When the probe field takes a large detuning value,the spatial distribution of the intensity and phase of the vertex four-wave mixing field can be effectively tuned by adjusting the Rabi frequency or detuning value of the coupled field.At the same time,we also provide a detailed explanation based on the dispersion relationship,and the results agree well with our simulation results. 展开更多
关键词 coherent optical effects four-wave mixing orbital angular momentum
下载PDF
Coherent effects in a three-photon CPT process of Ca+
2
作者 Qu LIU Bao-quan OU +1 位作者 Xi-wen ZHU Ke-lin GAO 《Frontiers of physics》 SCIE CSCD 2011年第3期258-261,共4页
Linewidth narrowing and other quantum coherent effects based on three-photon coherent population trapping (CPT) in Ca+ ions are investigated. If the propagation directions of the three lasers obey the phase matchin... Linewidth narrowing and other quantum coherent effects based on three-photon coherent population trapping (CPT) in Ca+ ions are investigated. If the propagation directions of the three lasers obey the phase matching condition, the dark linewidth resulting from the CPT can be very narrow, and it can be controlled by adjusting the parameters of the lasers. 展开更多
关键词 coherent population trapping (CPT) LINEWIDTH coherent effects
原文传递
Delay Effect on Coherent Transfer of Optical Frequency Based on a Triple-Pass Scheme 被引量:1
3
作者 Chao-qun Ma Li-Fei Wu +2 位作者 Jiao Gu Yan-He Chen Guo-Qing Chen 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第8期9-13,共5页
We demonstrate a triple-pass scheme for coherent transfer of optical frequency and the delay effect on the fiber phase noise compensation. It is theoretically proved that the delay effect consists of both fiber delay ... We demonstrate a triple-pass scheme for coherent transfer of optical frequency and the delay effect on the fiber phase noise compensation. It is theoretically proved that the delay effect consists of both fiber delay and servo delay. The delay effect confines the servo bandwidth within 1/8 and induces a residual fiber phase noise after noise compensation. For a 25-km-long fiber, the servo bandwidth is found to be around 1 k Hz, and the fiber phase noise is suppressed approaching to the theoretical limitation. The triple-pass scheme enables the simultaneous transfer of optical frequency to multiple remote users. The performance of noise compensator in the triple-pass scheme can achieve a similar level result compared with that in the double-pass scheme. 展开更多
关键词 Delay effect on coherent Transfer of Optical Frequency Based on a Triple-Pass Scheme AOM
下载PDF
Coherent population trapping magnetometer by differential detecting magneto–optic rotation effect 被引量:2
4
作者 张樊 田原 +1 位作者 张奕 顾思洪 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期355-358,共4页
A pocket coherent population trapping(CPT) atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting... A pocket coherent population trapping(CPT) atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting magneto–optic rotation effect,a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained.The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order,and the ability to detect weak magnetic fields is extended one-fold.Therefore,the proposed scheme is suited to realize a pocket-size CPT magnetometer. 展开更多
关键词 coherent population trapping atomic magnetometer magneto–optic rotation effect
下载PDF
THE EFFECTS OF VELOCITY RATIO ON THE LARGE SCALE COHERENT STRUCTURES IN FREE SHEAR LAYERS
5
作者 Zhang Hongquan and Shu Wei Tianjin University 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1991年第3期257-263,共7页
The velocity ratio of a free shear layer has an important influence on the spatial development of the large scale coherent structures in the layer. In this study, numerical simulations are performed to get an insight ... The velocity ratio of a free shear layer has an important influence on the spatial development of the large scale coherent structures in the layer. In this study, numerical simulations are performed to get an insight into this problem. The obtained numerical results agree quite well with those of a linear inviscid stability theory and the available experimental data. 展开更多
关键词 In THE effectS OF VELOCITY RATIO ON THE LARGE SCALE coherent STRUCTURES IN FREE SHEAR LAYERS
下载PDF
Comparison of brain functions between healthy participants and methamphetamine users with various addiction histories:Data analysis based on EEG and fNIRS
6
作者 Xuelin Gu Xiaoou Li Banghua Yang 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第3期41-55,共15页
The electroencephalogram(EEG)rhythm and functional near-infrared spectroscopy(fNIRS)activation levels have not been compared between a healthy control group(HCG)and methamphetamine user group(MUG)with different addict... The electroencephalogram(EEG)rhythm and functional near-infrared spectroscopy(fNIRS)activation levels have not been compared between a healthy control group(HCG)and methamphetamine user group(MUG)with different addiction histories.This study used 64-electrode EEG and fNIRS to conduct an experiment that analyzed the resting and craving states.The EEG and fNIRS data of 56 participants were collected,including 14 healthy participants,14 methamphetamine users with an addiction history of 0.5–5 years,14 users with an addiction history of 5–10 years,and 14 users with an addiction history of 10–15 years.Isolated effective coherence(iCoh)within the brain network was used to process the EEG data.Statistical analysis was performed to compare differences in iCoh among the delta,theta,alpha,beta,and gamma bands and explore oxyhemoglobin activation levels in the ventrolateral prefrontal cortex,dorsolateral prefrontal cortex,orbitofrontal cortex,and frontopolar prefrontal cortex(FPC)of the control group.Finally,the Kmeans,Gaussian mixed model(GMM),linear discriminant analysis(LDA),support vector machine(SVM),Bayes,and convolutional neural networks(CNN)algorithms were used to classify methamphetamine users based on drug and neutral images.A 3-class accuracy was achieved.Changes in EEG and fNIRS activation levels of HCG and MUG with varied addiction histories were demonstrated. 展开更多
关键词 Drug addiction history ELECTROENCEPHALOGRAM functional near-infrared spectroscopy isolated effective coherence addiction history classification
下载PDF
Nonlinear polarization effects and mitigation in polarization-division-multiplexed coherent transmission systems 被引量:3
7
作者 谢崇进 《Chinese Optics Letters》 SCIE EI CAS CSCD 2010年第9期844-851,共8页
Using numerical simulations, the nonlinear transmission performance of polarization-division-multiplexed quadrature-phase-shift-keying (PDM-QPSK) coherent systems is studied. It is found that inter-channel cross-pol... Using numerical simulations, the nonlinear transmission performance of polarization-division-multiplexed quadrature-phase-shift-keying (PDM-QPSK) coherent systems is studied. It is found that inter-channel cross-polarization modulation (XPolM) induced nonlinear polarization scattering can significantly degrade the transmission performance of PDM-QPSK coherent systems and change the perspective of dispersion management in optical coherent transmission systems. Some techniques to mitigate nonlinear polarization scattering in dispersion-managed PDM coherent transmission systems are discussed, including the use of time-interleaved return-to-zero (RZ) PDM formats, the use of periodic-group-delay PGD dispersion compensators, and the judicious addition of some polarization-mode-dispersion (PMD) in the transmission link. It is shown that if nonlinear polarization scattering can be well mitigated, a polarization multiplexed optical coherent transmission system with dispersion management could perform better than that without it. 展开更多
关键词 QPSK NRZ Nonlinear polarization effects and mitigation in polarization-division-multiplexed coherent transmission systems PDM WDM PGD
原文传递
EFFECTS OF WALL ROUGHNESS ON COHERENT STRUCTURE IN TURBULENT SHEAR FLOWS 被引量:1
8
作者 LIANG ZAICHAO LIU SHIHE, Research Institute of Water Conservancy and Hydraulic Power, Wuhan University of Hydraulic and Electric Engineering, Wuhan, Hubei, P.R. China 《Journal of Hydrodynamics》 SCIE EI CSCD 1989年第1期15-21,共7页
There are many examples that fluid flows on rough wall, such as channel flow in nature, pipe flow, etc. In order to know the flow structure of real fluids, it is important to study the effects of wall roughness on coh... There are many examples that fluid flows on rough wall, such as channel flow in nature, pipe flow, etc. In order to know the flow structure of real fluids, it is important to study the effects of wall roughness on coherent structure in turbulent shear flows. The experiments were carried out in a square glass channel, which is 600cm long, with the cross section of 30×25cm^2. The flow velocity was varied from 2 to 40 cm/s. Uniform sands whose diameters were 0.0012cm, 0.2gcm, 0.385cm, 0.594cm and 0.896cm respectively were glued to the floor of the channel. The rough Reynolds number Re_Δ= U_*Δ/ν=0.04~73, where U_*is the shear velocity, Δ is the diame- ter of uniform sand, v is the kinematic viscosity coefficient. Hydrogen bubble technique for flow visualization and HWL-II hot-film anemometer for velocity mea- surement were used in the experiments. 展开更多
关键词 effectS OF WALL ROUGHNESS ON coherent STRUCTURE IN TURBULENT SHEAR FLOWS FLOW
原文传递
Ground state cooling of an optomechanical resonator with double quantum interference processes
9
作者 Shuo Zhang Tan Li +2 位作者 Qian-Hen Duan Jian-Qi Zhang Wan-Su Bao 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第2期268-275,共8页
We present a cooling scheme with a tripod configuration atomic ensemble trapped in an optomechanical cavity.With the employment of two different quantum interference processes,our scheme illustrates that it is possibl... We present a cooling scheme with a tripod configuration atomic ensemble trapped in an optomechanical cavity.With the employment of two different quantum interference processes,our scheme illustrates that it is possible to cool a resonator to its ground state in the strong cavity-atom coupling regime.Moreover,with the assistance of one additional energy level,our scheme takes a larger cooling rate to realize the ground state cooling.In addition,this scheme is a feasible candidate for experimental applications. 展开更多
关键词 laser cooling coherent optical effects multiphoton processes OPTOMECHANICS
下载PDF
Strong violations of locality by testing Bell's inequality with improved entangled-photon systems
10
作者 王尧 樊代和 +1 位作者 郭伟杰 韦联福 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第8期327-334,共8页
Bell’s theorem states that quantum mechanics cannot be accounted for by any local theory. One of the examples is the existence of quantum non-locality is essentially violated by the local Bell’s inequality. Therefor... Bell’s theorem states that quantum mechanics cannot be accounted for by any local theory. One of the examples is the existence of quantum non-locality is essentially violated by the local Bell’s inequality. Therefore, the violation of Bell’s inequality(BI) has been regarded as one of the robust evidences of quantum mechanics. Until now, BI has been tested by many experiments, but the maximal violation(i.e., Cirel’son limit) has never been achieved. By improving the design of entangled sources and optimizing the measurement settings, in this work we report the stronger violations of the Clauser–Horne–Shimony–Holt(CHSH)-type Bell’s inequality. The biggest value of Bell’s function in our experiment reaches √to a significant one: S = 2.772 ± 0.063, approaching to the so-called Cirel’son limit in which the Bell function value is S = 22.Further improvement is possible by optimizing the entangled-photon sources. 展开更多
关键词 quantum entanglement coherent optical effects Bell inequality
下载PDF
Probe frequency- and field intensity-sensitive coherent control effects in an EIT-based periodic layered medium
11
作者 廖德超 吴俊杰 +1 位作者 沈建其 杨宗哲 《Chinese Optics Letters》 SCIE EI CAS CSCD 2012年第1期1-4,共4页
A periodic layered medium, with unit cells consisting of a dielectric and an electromagnetically-induced transparency (EIT)-based atomic vapor, is designed for light propagation manipulation. Considering that a dest... A periodic layered medium, with unit cells consisting of a dielectric and an electromagnetically-induced transparency (EIT)-based atomic vapor, is designed for light propagation manipulation. Considering that a destructive quantum interference relevant to a two-photon resonance emerges in EIT-based atoms interacting with both control and probe fields, an EIT-based periodic layered medium exhibits a flexible frequency-sensitive optical response, where a very small variation in the probe frequency can lead to a drastic variation in reflectance and transmittance. The present EIT-based periodic layered structure can result in controllable optical processes that depend sensitively on the external control field. The tunable and sensitive optical response induced by the quantum interference of a multi-level atomic system can be applied in the fabrication of new photonic and quantum optical devices. This material will also open a good perspective for the application of such designs in several new fields, including photonic microcircuits or integrated optical circuits. 展开更多
关键词 EIT Probe frequency and field intensity-sensitive coherent control effects in an EIT-based periodic layered medium
原文传递
Generalized Coherent States for Position-Dependent Effective Mass Systems
12
作者 Naila Amir Shahid Iqbal 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第12期615-620,共6页
A generalized scheme for the construction of coherent states in the context of position-dependent effective mass systems has been presented. This formalism is based on the ladder operators and associated algebra of th... A generalized scheme for the construction of coherent states in the context of position-dependent effective mass systems has been presented. This formalism is based on the ladder operators and associated algebra of the system which are obtained using the concepts of supersymmetric quantum mechanics and the property of shape invariance. In order to exemplify the general results and to analyze the properties of the coherent states, several examples have been considered. 展开更多
关键词 generalized coherent states supersymmetric quantum mechanics shape invariance ladder operators position-dependent effective mass systems non-linear oscillators Mandel parameter subPoissonian statistics
原文传递
Experimental demonstration of optical Bloch oscillation in electromagnetically induced photonic lattices
13
作者 Zhaoyang Zhang Shaohuan Ning +6 位作者 Hua Zhong Milivoj RBelić Yiqi Zhang Yuan Feng Shun Liang Yanpeng Zhang Min Xiao 《Fundamental Research》 CAS 2022年第3期401-404,共4页
The optical Bloch oscillation(OBO)is an optical-quantum analogy effect that is significant for light field manipulations,such as light beam localization,oscillation and tunneling.As an intra-band oscillation,OBO was i... The optical Bloch oscillation(OBO)is an optical-quantum analogy effect that is significant for light field manipulations,such as light beam localization,oscillation and tunneling.As an intra-band oscillation,OBO was important for optical investigations in photonic lattices and atomic vapors over an extended period of time.However,OBO in reconfigurable platforms is still an open topic,even though tunability is highly desired in developing modern photonic techniques.Here we theoretically establish and experimentally demonstrate OBO in an electromagnet-ically induced photonic lattice with a ramping refractive index,established in a coherently-prepared three-level 85 Rb atomic vapor under the electromagnetically induced transparency condition.This is achieved by interfering two coupling beams with Gaussian profiles and launching a probe beam that exhibits OBO within the resulting lattice.The induced reconfigurable photonic lattice possesses a transverse gradient,due to the innate edges of Gaussian beams,and sets a new stage for guiding the flow of light in periodic photonic environments.Our results should motivate better understanding of peculiar physical properties of an intriguing quantum-optical analogy in an atomic setting. 展开更多
关键词 Optical bloch oscillation Electromagnetically induced transparency Photonic lattice Atomic coherence effect Beam dynamics
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部