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Novel optical fiber current sensor based on magnetic fluid

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Chinese Optics Letters 2010年第4期8卷 392-394页

作者：胡涛赵勇李星陈菁菁吕志伟 Department of Automatic Testing and Control Harbin Institute of Technology College of Information Science and Engineering Northeastern University

A novel fiber optic Fabry-Perot（F-P） current sensor is developed based on magnetic fluid as the medium in F-P interference cavity.A signal demodulation method based on slanted fiber Bragg grating（FBG） wavelength measurement system is proposed.Theory and principle of electromagnetic-controlled refractive index of the magnetic fluid is described,as well as the structure of the sensor system.Preliminary experiments are carried out,and the results indicate that there is a fairly good linearity of the measurement characteristic.The thickness of magnetic fluid film and initial concentration will affect the measurement results.

关键词： Fiber Bragg gratings optical fibers optical materials Refractive index Sensors

Control of soliton interactions by use of super-Gaussian sliding-frequency filters

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Chinese Optics Letters 2008年第7期6卷 476-478页

作者：何影记田晋平周国生薛文瑞肖燕汪河洲 School of Electronics and Information Guangdong Polytechnic Normal UniversityGuangzhou 510665 2 State Key Laboratory of Optoelectronic Materials and TechnologiesSun Yat-Sen UniversityGuangzhou 510275 Department of Electronics and Information Technology and State Key Subjects of Optics Shanxi UniversityTaiyuan 030006 State Key Laboratory of Optoelectronic materials and Technologies Sun Yat-Sen UniversityGuangzhou 510275

We derived the theoretical results of soliton interactions in optical fiber with super-Gaussian sliding-frequency filters. The results demonstrate that the interactions between optical fiber solitons can be effectively suppressed by super-Gaussian sliding-frequency filters. And the results also show that the super-Gaussian filter with sliding is more effective in suppressing soliton interactions than that without sliding.

关键词： Fibers Flow interactions optical fibers optical materials Solitons Trellis codes Wave filters

SYNTHESIS AND optical PROPERTIES OF POLY (THIENYLACETYLENES)

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Chinese Journal of Polymer Science 1999年第1期17卷 81-86页

作者：唐本忠 Takashi Monde Department of Chemistry Hong Kong University of Science & Technology Clear Water Bay Kowloon Hong Kong China Central Research Laboratory Neos Co. Ltd Kosei-Cho Koga-Gun Shiga Japan

3-Ethynyl-4-(trimethylsilyl)thiophene (1a) and 3-ethynyl-4-bromothiophene (1b) selectively undergo acetylene polymerizations in the presence of the MoCl5- and WCl6-Ph3SiH catalysts to give soluble, high-molecular-weight poly(thienylacetylenes) (2) (M-w up to 602000) in high yields (up to 100%). Light transmission spectra of THF solutions of 2 continuously red-shift with increasing concentration. The concentratochromism shows a logarithmic concentration dependence; that is, the optical transitions of 2 are predictably tunable by simply changing their concentrations.

关键词： polyacetylenes poly(thienylacetylenes) conjugated polymers optical materials pi-pi interaction light transmission chromic effects

Rare earth doped cobalt aluminate blue as an environmentally benign colorant

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Journal of Advanced Ceramics 2012年第4期1卷 301-309页

作者： Sri Parasara RADHIKA Kalarical Janardhanan SREERAM Balachandran Unni NAIR Chemical Laboratory Central Leather Research InstituteCouncil of Scientific and Industrial ResearchAdyarChennai 600020India

Increasing energy cost calls for exterior coatings with high near infra-red reflectance,so as to reduce heat absorption and in turn cost of air-conditioning.While modulations of substrate,use of white metal oxides as pigments or under-layers has been reported in past,reports on metal oxide or doped metal oxide pigments with high NIR reflectance is scarce.We report for the first time a blue colored cobalt aluminate type pigment prepared through doping of cerium,praseodymium or neodymium.CIELAB color measurements and calculation ofDE indicated that the Nd doped sample had crystal size of(36±1)nm,bandgap value of(2.4±0.2)eV and color coordinates similar to that of cobalt aluminate.The molar ratio as estimated by EDX was found to be Al:Cu:Co:Ce:Nd:O=2:0.06:0.06:0.012:0.00012:6.18.The pigment was found to have potential applications as a cool blue colorant,owing to changes in optical properties arising out of crystal chemistry changes.Incorporation of rare earth metal ions was found to enhance the NIR reflectance by 10%,when compared to a conventional cobalt aluminate pigment.The oxide has been well characterized and its performance as a pigment evaluated.We have proposed that changes in crystal lattice when neodymium enters into Ce4+sites enhance the NIR reflectance by about 9%as against the entry of praseodymium.

关键词： optical materials oxides chemical synthesis environmental coatings color centers crystal structure defects

Influence of electrolyte temperature on spectral properties of porous silicon microcavity

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Chinese Optics Letters 2014年第A1期12卷 158-159页

作者：张红燕刘荣霞吕小毅贾振红 School of Physical Science and Technology Xinjiang University Urumqi 830046 China Colleges of Information Science and Engineering Xinjiang University Urumqi 830046 China

A porous silicon microcavity （PSM） is highly sensitive for sensing applications due to its high surface area and a narrow resonance peak. In this letter, we fabricated the PSM by alternate current density from a low value to a high value during double-tank electrochemical anodization at different electrolyte temperatures. Results show that with the increase of the electrolyte temperature, the rate of the PS etching becomes faster and the refractive index of the PS layer becomes smaller. The thickness of the PS increases faster than the decrease of the refractive index of the PS.

关键词： 240.6695 Surface-enhanced Raman scattering 160.4670 optical materials 160.3900 Metals 300.6450 Spectroscopy, Raman

Multi-wavelength pulse generation using flattop optical frequency comb and arrayed waveguide grating

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Chinese Optics Letters 2012年第12期10卷 82-83页

作者：窦玉杰张洪明姚敏玉 State Key Laboratory on Integrated Optoelectronics Tsinghua National Laboratory for Information Science and TechnologyDepartment of Electronic EngineeringTsinghua University

A scheme of multi-wavelength pulse generator using optical frequency comb and arrayed waveguide grating （AWG） is proposed and experimentally demonstrated. A flattop optical frequency comb is shaped into multiple narrowband Gaussian spectra by using an AWG which contains a number of Gaussian channels, and then multi-wavelength optical pulses are achieved. In the experiment, six wavelength pulses with full width at half-maximum （FWHM） of 14.6 ps at I0 GHz are obtained, and two wavelength-interleaved pulse trains at 20 GHz and four wavelength-interleaved multi-wavelength optical pulses. This scheme has and time-interval can be readily controlled. pulse trains at 40 GHz are demonstrated by using the flexibility because the pulse width, the repetition rate,

关键词： Natural frequencies optical materials Pulse generators Telecommunication Wavelength

Effect of nanocrystals on up-conversion luminescence of Er^(3+),Yb^(3+) co-doped glass-ceramics

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Chinese Optics Letters 2005年第8期3卷 469-471页

作者：余华赵丽娟孟婕梁沁禹宣伊唐柏权许京军 Photonics Research Center College of Physical Science Nankai University

Different up-conversion luminescent spectra of Er^3＋ ions were observed in the oxyfluoride glass-ceramics. The ratio of two fluorides in the original compositions was modified in order to form different nanocrystals. The intensity of up-conversion luminescence increased sharply when the ratio of PbF2 and CdF2 was 40：10. The data of differential thermal analysis and X-ray diffraction were used to explain the optimization fluoride ratio. The intensity of up-conversion luminescence is not only decided by the crystallizability but also mainly related with the stoiehiometric proportion of fluoride nanocrystals in the glass-ceramics.

关键词： Differential thermal analysis Erbium Luminescence of inorganic solids Nanostructured materials optical materials Rare earth additions X ray diffraction analysis Ytterbium

Antireflective characteristics of triangular shaped gratings

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Chinese Optics Letters 2005年第9期3卷 497-499页

作者：王建国邵建达王素梅贺洪波范正修 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

The antireflection properties of triangular shaped gratings are studied by a combination of the effective medium theory and the anisotropic thin-film theory. The triangular shaped structures are analyzed as a function of grating period, filling factor, and groove depth, and the antireflective characteristics are also studied when visible-infrared light is incident upon them. Numerical examples are given for gratings on glass substrate with refractive index of 1.5. The results show that this kind of grating is capable of reducing reflections, and could achieve very low reflectivity over a wide field of view and a wide waveband by choosing appropriate parameters.

关键词： Dielectric films optical materials optical systems Polarization Refractive index Schematic diagrams

Differential optical gain in a GaInN/AlGaN quantum dot

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Journal of Semiconductors 2017年第6期38卷 1-7页

作者： K.Jaya Bala A.John Peter Department of Physics GTN Arts College Dindigul-624 005 India PG & Research Department of Physics Government Arts College Melur-625 106 Madurai India

Electronic and optical properties are obtained with the increase in indium alloy content（x）in a Ga1-xInxN/Al0.2Ga0.8N quantum dot.The barrier height with the different In alloy contents is applied to acquire the confinement potentials.The results are obtained taking into consideration geometrical confinement effect.The optical absorption coefficient with the photon energy is observed in a Ga（1-x）InxN/Al0.2Ga0.8N quantum dot.The optical output with the injection current density and the threshold optical pump intensity for various In alloy contents are studied.The differential gain as functions of indium alloy content,charge density and the dot radii in the Ga1-xInxN/Al0.2Ga0.8N quantum dot are investigated.The exciton binding energy is calculated in order to obtain the exciton density,the optical gain and the threshold current density in the Ga1-xInxN/Al0.2Ga0.8N quantum dot.The results show that the red shift energy with an increase in In alloy content is found and the differential gain increases with the charge carrier density.

关键词： semiconductors quantum dots nitrides optical materials