检索结果-南通市图书馆

Chinese Physics B 2010年第2期19卷 504-511页

作者：季小玲蒲政才 College of Physics Sichuan Normal University

Based on a recently formulated unified theory of coherence and polarization, a method is described to study turbulence-induced changes in the polarization, the coherence and the spectrum of partially coherent electromagnetic beams on propagation. The electromagnetic Gaussian Schell-model beam is taken as a typical example of partially coherent electromagnetic beams, and the closed-form expressions for the degree of polarization, the degree of coherence and the spectrum of electromagnetic Gaussian Schell-model beams propagating through atmospheric turbulence are derived in the quadratic approximation of Rytov＇s phase structure function. Some interesting results are obtained, which are illustrated by numerical examples and are explained in physics.

关键词： unified theory of coherence and polarization turbulence partially coherent electromagnetic beams degree of polarization degree of coherence spectrum

Regulated polarization degree of upconversion luminescence and multiple anti-counterfeit applications

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2172-2183页

作者： Dong-Ping Wen Ping Chen Yi Liang Xiao-Ming Mo Cao-Feng Pan Center On Nanoenergy Research Guangxi Key Laboratory for Relativistic AstrophysicsSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Key Laboratory of Micronano Energy and Sensor CAS Center for Excellence in NanoscienceBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100140China

polarization upconversion luminescence(PUCL)of lanthanide ions(Ln^(3+))has been widely used in single particle tracking,microfluidics detection,three-dimensional displays,and so ***,no effective strategy has been developed for modulating *** we report a strategy to regulate PUCL in Ho^(3+)-doped NaYF4single nanorods based on the number of upconversion *** constructing a multiphoton upconversion system for Ho^(3+),we regulate the degree of polarization(DOP)of PUCL from 0.590 for two-photon luminescence to 0.929 for three-photon upconversion luminescence(UCL).Furthermore,our strategy is verified from cross-relaxation between Ho^(3+)and Yb^(3+),excitation wavelength,excitation power density,and local site *** this regulation strategy of PUCL has also been achieved in Tm^(3+),with the DOP ranging from 0.233 for two-photon luminescence to 0.925 for four-photon UCL Besides,multi-dimensional anti-counterfeiting display has been explored with *** work provides an effective strategy for regulating PUCL and also provides more opportunities for the development of polarization display optical encoding,anti-counterfeiting,and integrated optical devices.

关键词： polarization upconversion luminescence degree of polarization Population density of excited state Number of upconversion photons polarization anti-counterfeitingdisplay

polarization full feedback external cavity of open loop spectral beam combining based on multi-single emitters laser diode

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第5期22卷 80-84页

作者：胡满张伟桥曹澎李彤彤周旭彦郑婉华 Laboratory of Solid-State Optoelectronics Information Technology Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Weifang Academy of Advanced Opto-Electronic Circuits Weifang 261071China State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China College of Future Technology University of Chinese Academy of SciencesBeijing 101408China

In this paper,a spectral beam combining(SBC)structure of multi-single emitters laser diode based on a polarization full feedback(PFF)external cavity is proposed and *** maximum combining efficiency is 75.6%,which leads to an output power of 38.48 W,a degree of polarization(DOP)of 99.42%,and electro-optical conversion efficiency of 35.63%under continuous wave operation at a current of 8 *** to the conventional SBC,the output power,the combining efficiency,the electro-optical conversion efficiency,and the DOP of the PFF-SBC structure present improvements of 5.73 W,11.26 percentage points,5.3 percentage points,and 7.26 percentage points,*** results show that this SBC method can achieve a high efficiency and linearly polarized laser output of SBC,thereby making the subsequent polarization beam-combining efficiency approach the limit.

关键词： diode laser spectral beam combining high efficiency degree of polarization external cavity feedback

polarization mode dispersion compensation in a novel dual polarization differential quadrature phase shift keying system

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2011年第11期20卷 241-247页

作者：秦江星席丽霞张晓光田凤 State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

A novel dual polarization differential quadrature phase shift keying （DP-DQPSK） system is proposed, whose receiver is the same as the single polarization DQPSK system, while it does not need polarization de-multiplexing like the conventional polarization division multiplexing QPSK （PDM-QPSK）. polarization mode dispersion （PMD） is mainly considered and PMD compensation for the DP-DQPSK system is studied. As the feedback signal for PMD compensation, the degree of polarization of the signals is discussed in detail. The results show that PMD tolerance can be improved by 89 ps within 1 dB optical signal noise ratio penalty after PMD compensation for the DP-DQPSK system.

关键词： dual polarization DQPSK system one receiver degree of polarization polarization modedispersion compensation

Optical polarization characteristics for AlGaN-based light-emitting diodes with AlGaN multilayer structure as well layer

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第4期30卷 535-541页

作者：薛露李毅葛梅王美玉朱友华 School of Information Science and Technology&Tongke School of Microelectronics Nantong UniversityNantong 226019China

The optical properties of AlGaN-based quantum well(QW)structure with two coupled thin well layers are investigated by the six-by-six K-P *** with the conventional structure,the new structure,especially the one with lower Al-content in the barrier layer,can enhance the TE-/TM-polarized total spontaneous emission rate due to the strong quantum confinement and wide recombination *** the conventional QW structure,the reduction of well thickness can lead the degree of polarization(DOP)to decrease and the internal quantum efficiency(IQE)to *** using the coupled thin well layers,the DOP for the structure with high Al-content in the barrier layer can be improved,while the DOP will further decrease with low Al-content in the barrier *** can be attributed to the band adjustment induced by the combination of barrier height and well layer *** IQE can also be further enhanced to 14.8%-20.5%for various Al-content of barrier layer at J=100 A/cm^(2).In addition,the efficiency droop effect can be expected to be suppressed compared with the conventional structure.

关键词： Al Ga N-based quantum well K-P method internal quantum efficiency degree of polarization

Monitoring the Evolution of 1991 Pinatubo Aerosols Over Beijing by Twilight Observation

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 1994年第6期 107-112页

作者：吴北婴吕达仁 Academia Sinica Beijing 100029 Institute of Atmospheric Physics PRC

A highly sensitive, automatically operating skylight photometer has been developed in the Institute of Atmospheric Physics, Academia Sinica for the purpose of monitoring the intensity and degree of polarization of skylight during the twilight period. Since June 1991, data have been obtained in more than 30 d with the visibility greater than 25 km. This paper focuses on the observation of the degree of polarization of skylight at 0.7 μm in the zenith direction and related results by model simulations and analyses using both polarization and lidar data.

关键词： twilight photometer degree of polarization stratospheric aerosols.