The bonding status and chemical environment of SiO4 and AlO4 tetrahedras of three types of geopolymeric products were systematically investigated by infrared spectroscopy. The relationship between amorphous geopolymer...The bonding status and chemical environment of SiO4 and AlO4 tetrahedras of three types of geopolymeric products were systematically investigated by infrared spectroscopy. The relationship between amorphous geopolymeric products and zeolite crystals with the same overall chemical compositions was also discussed. The infrared evidence shows that SiO4 tetrahedra is partially bonded by AlO4 during the hydration process of geopolymeric cement. The two types of tetrahedras jointly construct the three dimensional framework structures of the geopolymeric products. The mutual transformation between geopolymeric products and corresponding zeolite crystals will take place once the reaction condition is suitable, which reveals that the nature ofgeopolymeric products are probably the amorphous equivalent of the corresponding zeolite crystals.展开更多
A multidisciplinary approach for the production and characterization of a series of high concentration Er3+activated SrLaGa3 O7(abbreviated as Er:SLGO)crystal fibers is shown to have a great promise for implementation...A multidisciplinary approach for the production and characterization of a series of high concentration Er3+activated SrLaGa3 O7(abbreviated as Er:SLGO)crystal fibers is shown to have a great promise for implementation in mid-infrared laser applications.The current approach includes the design and formation of unique layered tetrahedral network structures with several kinds of rare earth(RE)ions including Er ions distributing statistically between layers,such as Er:SLGO,Er,Nd:SLGO,Er,Yb,Ho:SLGO,Er,Eu:SLGO and Er,Ho:SLGO.Five kinds of Er:SLGO crystal fibers were designed to grow via a micropulling down method.Spectroscopic analyses show that Er,Yb,Ho:SLGO and Nd,Er:SLGO crystal fibers were superiorly endowed with inhomogeneous broadening absorption and strong emission.The unique structural components design enables the generation of improved absorption and emission recombination,and the inhibition of self-termination as well.Generally,the use of structural components design may warrant high-efficiency emissions in RE-doped crystal fibers.展开更多
We present a new scheme for visibly-opaque but near-infrared-transmitting filters involving 7 layers based on one-dimensional ternary photonic crystals, with capabilities in reaching nearly 100% transmission efficienc...We present a new scheme for visibly-opaque but near-infrared-transmitting filters involving 7 layers based on one-dimensional ternary photonic crystals, with capabilities in reaching nearly 100% transmission efficiency in the near-infrared region. Different decorative reflection colors can be created by adding additional three layers while maintaining the near-infrared transmission performance. In addition, our proposed structural colors show great angular insensitivity up to ±60° for both transverse electric and transverse magnetic polarizations, which are highly desired in various fields. The facile strategy described here involves a simple deposit!on method for the fabrication, thereby having great potential in diverse applications such as image sensors, anti-counterfeit tag, and optical measurement systems.展开更多
Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to...Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to4I15/2 →4I13/2,4I13/2 →4I11/2,and4I11/2 →4I9/2 transitions,respectively,are observed.LiYF4 single crystals possess high transmittance of over 85% in the 2.5-6 μm range.The large emission crosssections of Tm-doped crystals at 2.4 μm（1.9×10-20cm2） and Nd-doped crystals at 4.2 μm（0.84×10-20 cm2） as well as the high rare-earth doping concentrations,excellent optical transmission,and chemicalphysical properties of the resultant samples indicate that Nd3＋and Tm3＋singly doped crystals may be promising materials for application in MIR lasers.展开更多
N-doped FZ-Si crystals and N-doped NTD FZ-Si crystals and their annealing behavior have been studied by IR spectrum. Two models of nitrogen configuration, nearly substitutional nitrogen and interstitial nitrogen pair,...N-doped FZ-Si crystals and N-doped NTD FZ-Si crystals and their annealing behavior have been studied by IR spectrum. Two models of nitrogen configuration, nearly substitutional nitrogen and interstitial nitrogen pair, have been proposed and two nitrogen-related IR absorption peaks at 767cm-1 and 963cm-1 have been well explained.展开更多
Tourmaline is an important functional and gem material. The current study examines pink, green, and brownish-green tourmalines from Altay deposit. Based on X-ray fluorescence （XRF） quantitative analyses and ultrario...Tourmaline is an important functional and gem material. The current study examines pink, green, and brownish-green tourmalines from Altay deposit. Based on X-ray fluorescence （XRF） quantitative analyses and ultrariolet-visible-near-infrared （UV-VIS NIR） spectral analyses in combination with annealing ex- periments, the color center of tourmaline is found to be related to the d - d transitions of ions or the d - d transitions of exchange coupled ions. Annealing crystMs treatment affects the color improvement of tourmaline展开更多
Fabrication details of air-bridged Kerr nonlinear polymer photonic crystal slab structures are presented. Both the two-dimensional photonic crystal slab and the one-dimensional nanobeam structures are fabricated using...Fabrication details of air-bridged Kerr nonlinear polymer photonic crystal slab structures are presented. Both the two-dimensional photonic crystal slab and the one-dimensional nanobeam structures are fabricated using direct focused ion beam etching and subsequent wet chemical etching. The scanning electron microscopy images show the uniformity and homogeneity of the cylindrical air holes. The optical measurement in the near-infrared region is implemented using the tapered fiber coupling method, and the results agree with the numerical calculations by using the three-dimensional finite-difference time-domain method.展开更多
Determination of substitutional carbon in SI-GaAs thin wafers was investigated by FT-IR microscope at room temperature for the first time. The experimental results showed that the carbon concentration in GaAs thin waf...Determination of substitutional carbon in SI-GaAs thin wafers was investigated by FT-IR microscope at room temperature for the first time. The experimental results showed that the carbon concentration in GaAs thin wafers can be measured directly with simple treatment. The calculation method of carbon concentration is in agreement with that for normal IR spectrum with 0.5cm-1 resolution. The resolution of 1cm-1 can be taken in order to obtain a high signal-to-noise (S/N) ratio using 2.34×1016 cm-2 calibration factor for calculating carbon concentration at room temperature.展开更多
High-power femtosecond lasers beyond 5μm are attractive for strong-field physics with mid-infrared(IR)fields but are difficult to scale up.In optical parametric chirped-pulse amplification(OPCPA)at mid-IR wavelengths...High-power femtosecond lasers beyond 5μm are attractive for strong-field physics with mid-infrared(IR)fields but are difficult to scale up.In optical parametric chirped-pulse amplification(OPCPA)at mid-IR wavelengths,a nonlinear crystal is vital,and its transmittance,dispersion,nonlinear coefficient and size determine the achievable power and wavelength.OPCPA beyond 5μm routinely relies on semiconductor crystals because common oxide crystals are not transparent in this spectral range.However,the small size and low damage threshold of semiconductor crystals fundamentally limit the peak power to gigawatts.In this paper,we design a terawatt-class OPCPA system at 5.2μm based on a new kind of oxide crystal of La3Ga5.5Nb0.5O14(LGN).The extended transparent range,high damage threshold,superior phase-matching characteristics and large size of LGN enable the generation of 0.13 TW seven-cycle pulses at5.2μm.This design fully relies on the state-of-the-art OPCPA technology of an octave-spanning ultrafast Ti:sapphire laser and a thin-disk Yb:YAG laser,offering the performance characteristics of high power,a high repetition rate and a stable carrier-envelope phase.展开更多
基金Jiangsu Province Natural Science Foundation(No.BK2006555,BK2005216)the West Communication Construction Foundation(No.2006ZB12)the Nanjing Hydraulic Research Institute Opening and Flowing Research Foundation(No.Yk90508)
文摘The bonding status and chemical environment of SiO4 and AlO4 tetrahedras of three types of geopolymeric products were systematically investigated by infrared spectroscopy. The relationship between amorphous geopolymeric products and zeolite crystals with the same overall chemical compositions was also discussed. The infrared evidence shows that SiO4 tetrahedra is partially bonded by AlO4 during the hydration process of geopolymeric cement. The two types of tetrahedras jointly construct the three dimensional framework structures of the geopolymeric products. The mutual transformation between geopolymeric products and corresponding zeolite crystals will take place once the reaction condition is suitable, which reveals that the nature ofgeopolymeric products are probably the amorphous equivalent of the corresponding zeolite crystals.
基金Project supported by National Natural Science Foundation of China(51832007,51472240,51872286,61675204)Science and Technology Plan Leading Project of Fujian Province(2018H0046)+1 种基金State Key Laboratory of Rare Earth Resource Utilization(RERU2018004,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences)the National Key Research and Development Program of China(2016YFB0701002)。
文摘A multidisciplinary approach for the production and characterization of a series of high concentration Er3+activated SrLaGa3 O7(abbreviated as Er:SLGO)crystal fibers is shown to have a great promise for implementation in mid-infrared laser applications.The current approach includes the design and formation of unique layered tetrahedral network structures with several kinds of rare earth(RE)ions including Er ions distributing statistically between layers,such as Er:SLGO,Er,Nd:SLGO,Er,Yb,Ho:SLGO,Er,Eu:SLGO and Er,Ho:SLGO.Five kinds of Er:SLGO crystal fibers were designed to grow via a micropulling down method.Spectroscopic analyses show that Er,Yb,Ho:SLGO and Nd,Er:SLGO crystal fibers were superiorly endowed with inhomogeneous broadening absorption and strong emission.The unique structural components design enables the generation of improved absorption and emission recombination,and the inhibition of self-termination as well.Generally,the use of structural components design may warrant high-efficiency emissions in RE-doped crystal fibers.
基金National Science Foundation Grant (No. CMMI-1727918) for the partial support of this workC. G. J. acknowledges the support by Rackham Graduate Student Research Grant from the University of Michigan.
文摘We present a new scheme for visibly-opaque but near-infrared-transmitting filters involving 7 layers based on one-dimensional ternary photonic crystals, with capabilities in reaching nearly 100% transmission efficiency in the near-infrared region. Different decorative reflection colors can be created by adding additional three layers while maintaining the near-infrared transmission performance. In addition, our proposed structural colors show great angular insensitivity up to ±60° for both transverse electric and transverse magnetic polarizations, which are highly desired in various fields. The facile strategy described here involves a simple deposit!on method for the fabrication, thereby having great potential in diverse applications such as image sensors, anti-counterfeit tag, and optical measurement systems.
基金supported by the National Natural Science Foundation of China(Nos.51272109 and 50972061)the Natural Science Foundation of Zhejiang Province(No.R4100364)+1 种基金the Natural Science Foundation of Ningbo City(No.2012A610115)the K.C.Wong Magna Fund in Ningbo University
文摘Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to4I15/2 →4I13/2,4I13/2 →4I11/2,and4I11/2 →4I9/2 transitions,respectively,are observed.LiYF4 single crystals possess high transmittance of over 85% in the 2.5-6 μm range.The large emission crosssections of Tm-doped crystals at 2.4 μm（1.9×10-20cm2） and Nd-doped crystals at 4.2 μm（0.84×10-20 cm2） as well as the high rare-earth doping concentrations,excellent optical transmission,and chemicalphysical properties of the resultant samples indicate that Nd3＋and Tm3＋singly doped crystals may be promising materials for application in MIR lasers.
文摘N-doped FZ-Si crystals and N-doped NTD FZ-Si crystals and their annealing behavior have been studied by IR spectrum. Two models of nitrogen configuration, nearly substitutional nitrogen and interstitial nitrogen pair, have been proposed and two nitrogen-related IR absorption peaks at 767cm-1 and 963cm-1 have been well explained.
文摘Tourmaline is an important functional and gem material. The current study examines pink, green, and brownish-green tourmalines from Altay deposit. Based on X-ray fluorescence （XRF） quantitative analyses and ultrariolet-visible-near-infrared （UV-VIS NIR） spectral analyses in combination with annealing ex- periments, the color center of tourmaline is found to be related to the d - d transitions of ions or the d - d transitions of exchange coupled ions. Annealing crystMs treatment affects the color improvement of tourmaline
基金supported by the National Basic Research Foundation of China(No.2011CB922002)the Knowledge Innovation Program of Chinese Academy of Sciences(No.Y1V2013L11)
文摘Fabrication details of air-bridged Kerr nonlinear polymer photonic crystal slab structures are presented. Both the two-dimensional photonic crystal slab and the one-dimensional nanobeam structures are fabricated using direct focused ion beam etching and subsequent wet chemical etching. The scanning electron microscopy images show the uniformity and homogeneity of the cylindrical air holes. The optical measurement in the near-infrared region is implemented using the tapered fiber coupling method, and the results agree with the numerical calculations by using the three-dimensional finite-difference time-domain method.
文摘Determination of substitutional carbon in SI-GaAs thin wafers was investigated by FT-IR microscope at room temperature for the first time. The experimental results showed that the carbon concentration in GaAs thin wafers can be measured directly with simple treatment. The calculation method of carbon concentration is in agreement with that for normal IR spectrum with 0.5cm-1 resolution. The resolution of 1cm-1 can be taken in order to obtain a high signal-to-noise (S/N) ratio using 2.34×1016 cm-2 calibration factor for calculating carbon concentration at room temperature.
基金supported in part by the National Natural Science Foundation of China(Nos.6170512861727820 and 91850203)Science and Technology Commission of Shanghai Municipality(Nos.17YF1409100 and17ZR1414000)。
文摘High-power femtosecond lasers beyond 5μm are attractive for strong-field physics with mid-infrared(IR)fields but are difficult to scale up.In optical parametric chirped-pulse amplification(OPCPA)at mid-IR wavelengths,a nonlinear crystal is vital,and its transmittance,dispersion,nonlinear coefficient and size determine the achievable power and wavelength.OPCPA beyond 5μm routinely relies on semiconductor crystals because common oxide crystals are not transparent in this spectral range.However,the small size and low damage threshold of semiconductor crystals fundamentally limit the peak power to gigawatts.In this paper,we design a terawatt-class OPCPA system at 5.2μm based on a new kind of oxide crystal of La3Ga5.5Nb0.5O14(LGN).The extended transparent range,high damage threshold,superior phase-matching characteristics and large size of LGN enable the generation of 0.13 TW seven-cycle pulses at5.2μm.This design fully relies on the state-of-the-art OPCPA technology of an octave-spanning ultrafast Ti:sapphire laser and a thin-disk Yb:YAG laser,offering the performance characteristics of high power,a high repetition rate and a stable carrier-envelope phase.
