We report an Er3+-doped fluorogallate glass with good thermal and chemical stability. The low maximum phonon energy and high mid-infrared (IR) transmittance of the glass are confirmed by Raman and IR spectra, respe...We report an Er3+-doped fluorogallate glass with good thermal and chemical stability. The low maximum phonon energy and high mid-infrared (IR) transmittance of the glass are confirmed by Raman and IR spectra, respectively. Based on Judd-Ofelt theory, intensity parameters and radiative properties are determined from the absorption and emission spectra. The proposed glass possesses a large fluorescence branching ratio β (21.71%) and a maximum stimulated emission cross-section σem of Er3+:4 I11/2 → 4 I13/2 transition at 2.71 μm (1.04 × 10^-20 cm2). The results indicate that it can be potentially applied in high-power 2.7 μm fiber lasers.展开更多
We demonstrate an efficiency-enhanced picosecond (ps) mid-infrared radiation via optical parametric downconversion. Based on a cascaded periodically poled MgO-doped stoiehiometric lithium tantalate crystal (MgO:sP...We demonstrate an efficiency-enhanced picosecond (ps) mid-infrared radiation via optical parametric downconversion. Based on a cascaded periodically poled MgO-doped stoiehiometric lithium tantalate crystal (MgO:sPPLT), a tandem optical parametric oscillation-optical parametric amplification (OPO-OPA) process is achieved. Compared with a single OPO process, the conversion efficiency obtains an enhancement of 71%.展开更多
The scattering properties of ZnO nanospheres with four different particle diameters of 10, 50, 100, and 200 nm suspended in water are investigated theoretical and experimentally in the spectral range of the entire vis...The scattering properties of ZnO nanospheres with four different particle diameters of 10, 50, 100, and 200 nm suspended in water are investigated theoretical and experimentally in the spectral range of the entire visible range and part of the near-infrared region. The scattering properties of ZnO nanospheres suspended in water are described by employing three main parameters: the angular distribution of the scattering intensity I, the scattering extinction coefficient ascat, and the scattering cross section ascat. The results indicate that (i) at a certain wavelength, the angular distribution of the scattering intensity appears as an obviously forward- propagating feature, and the forward-scattering intensity is dominant gradually when the particle diameter in- creases from 10 to 200 nm, and (ii) the scattering extinction coefficient and cross section can be determined by using the measured transmittance changes of a pure water sample and a given ZnO sample; they all are shown to be dependent on the particle size and incident wavelength. The experimental results of four different scattering samples agree well with the theoretical predictions within the given wavelength range.展开更多
Retrieving snow surface reflectance is difficult in optical remote sensing. Hence, this letter evaluates five surface reflectance models, including the Ross-Li, Roujean, Walthall, modified Rahman and Staylor models, i...Retrieving snow surface reflectance is difficult in optical remote sensing. Hence, this letter evaluates five surface reflectance models, including the Ross-Li, Roujean, Walthall, modified Rahman and Staylor models, in terms of their capacities to capture snow reflectance signatures using ground measurements in Antarctica. The biases of all the models are less than 0.0003 in both visible and near-infrared regions. Moreover, with the exception of the Staylor model, all models have root-mean-square errors of around 0.02, indicating that they can simulate the reflectance magnitude well. The R2 performances of the Ross-Li and Roujean models are higher than those of the others, indicating that these two models can capture the angle distribution of snow surface reflectance better.展开更多
The steady-state stimulated Raman scattering (SRS) gain with different excitation wavelengths ranging from 400 to 1100 nm of tungstate crystals, SrWO4 and BaWO4, is systematically researched. As excitation frequency...The steady-state stimulated Raman scattering (SRS) gain with different excitation wavelengths ranging from 400 to 1100 nm of tungstate crystals, SrWO4 and BaWO4, is systematically researched. As excitation frequency is close to electronic transition frequency, molecular polarizability is not a constant, which has to be taken into account in our work. The experiment and theory agree well with each other and show that SRS gain is not only proportional to Stokes light frequency, but is also inversely proportional to biquadratic excitation frequency.展开更多
Bi-doped SiO2-Al2O3-GeO2 fiber preforms are prepared by modified chemical vapor deposition (MCVD) and solution doping process. The characteristic spectra of the preforms and fibers are experimentally investigated, a...Bi-doped SiO2-Al2O3-GeO2 fiber preforms are prepared by modified chemical vapor deposition (MCVD) and solution doping process. The characteristic spectra of the preforms and fibers are experimentally investigated, and a distinct difference in emission between the two is observed. Under 808-nm excitation, an ultra-broad near-infrared (NIR) emission with full-width at half-maximum (FWHM) of 495 nm is observed in the Bi-doped fiber. This observation, to our knowledge, is the first in this field. The NIR emission consists of two bands, which may be ascribed to the Bi0 and Bi+ species, respectively. This Bi-doDed fiber is promising for broadband or)tical amolification and widely tunable laser.展开更多
We demonstrate the near-infrared (NIR) organic light-emitting devices (OLEDs) based on copper hexade-cafluorophthalocyanine (CuPcF16) doped into 2,2,2”-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzimidazole] (T...We demonstrate the near-infrared (NIR) organic light-emitting devices (OLEDs) based on copper hexade-cafluorophthalocyanine (CuPcF16) doped into 2,2,2”-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzimidazole] (TPBI). The device structure is ITO/ NPB/ TPBI:CuPcF16/BCP/Alq3/Al. Room-temperature electro- luminescence is observed at about 1106 nm due to transitions from the first excited triplet state to the ground state (T1-S0) of CuPcF16. The result indicates that FSrster and Dexter energy transfers play a minor role in these devices, while the direct charge trapping is the dominant mechanism. The absorption spectra of CuPeF16 solution in pyridine and vacuum sublimed films on quartz have also been investigated.展开更多
High-sensitivity and broad bandwidth photo-detector devices are important for both fundamental studies and high-technology applications. Here, by using three-dimensional (3D) finite-difference time-domain simulation...High-sensitivity and broad bandwidth photo-detector devices are important for both fundamental studies and high-technology applications. Here, by using three-dimensional (3D) finite-difference time-domain simulation, we design an optimized 3D multi-layer gold nano-antenna to enhance the near-infrared (NIR) absorption of germanium nanoparticles. The key ingredient is the simultaneous presence of multiple plasmonic resonance modes with strong light-harvesting effect that encompass a broad bandwidth of germanium absorption band. The simulation results show more than two orders of magnitude enhanced absorption efficiency of gernanium around 1550 nm. The design opens up a promising way to build high-sensitivity and broad bandwidth NIR photo-detectors.展开更多
The emerging perfect-absorber metamaterials (PAMs) provide an alternative material approach for the next generation of electromagnetic detection at any frequency band of interest. One type of dual cross-shaped PAMs ...The emerging perfect-absorber metamaterials (PAMs) provide an alternative material approach for the next generation of electromagnetic detection at any frequency band of interest. One type of dual cross-shaped PAMs is developed to obtain multiplex-band spectrum absorption at mid-infrared region. Three distinct absorption peaks are attributed to the polarization sensitivity excitation of the plasmonic resonance. The charge density distributions, which are excited by resonant electromagnetic waves passing through the PAMs medium, provide insights into the observed absorption behavior. We find that the retrieved optical properties of the PAMs including permittivity and permeability are still consistent with the sum of the Drude and Lorentz type models at wavelengths ranging from 2.0 to 10.0μm. Such multiplex-band absorption properties enable the proposed PAMs a powerful tool for the direct detection of multiple molecular vibrational structures, and for multiple spectra infrared detection.展开更多
The feasibility of fenestration operation in middle ear bone with pulsed infrared laser is evaluated. Healthy male New Zealand rabbits in vivo are used in the experiment. Middle ear mastoid bone of animal model is com...The feasibility of fenestration operation in middle ear bone with pulsed infrared laser is evaluated. Healthy male New Zealand rabbits in vivo are used in the experiment. Middle ear mastoid bone of animal model is completely exposed with conventional methods, and then a pulsed CO2 laser (10.6 μm) and an Er:YAG laser (2.94 μm) are used to perform the fenestration operation. Diamond drill is also used as a control group. The total operation time and light irradiation time are recorded and the opening efficiency is assessed. The morphological changes and thermal damage around the opening window on the middle ear bone are examined. It is shown that both laser systems are suitable for the fenestration operation in middle ear bone, and this no-touch technique has a lot of benefits compared with traditional methods. The bleeding during operation has an important effect on operation time and thermal injury and needs to be controlled efficiently in further study.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
We theoretically investigate multiple electron rescatterings in high-order harmonic generation with a wide range of driving laser wavelengths. In order to obtain a clear and intuitive insight, the time-frequency analy...We theoretically investigate multiple electron rescatterings in high-order harmonic generation with a wide range of driving laser wavelengths. In order to obtain a clear and intuitive insight, the time-frequency analysis of the dipole acceleration calculated by the numerical solution of the time-dependent SchrSdinger equation is per- formed and compared with the classical electron trajectory calculation. The result shows that in the mid-infrared regime, the high-order electron trajectory associated with multiple rescatterings plays a more important role than the usually referred-to "long and "short" electron trajectories. To provide quantitative evidence, the strong-field approximation is used to calculate the yield ratio of the high-order harmonic generation from the first rescattering and the multiple rescatterings.展开更多
A compact static infrared broadband snapshot imaging spectrometer (IBSIS) is presented. It consists of a telescope, three prisms, a focusing lens, and a detector. The first prism disperses sharply in the near-infrar...A compact static infrared broadband snapshot imaging spectrometer (IBSIS) is presented. It consists of a telescope, three prisms, a focusing lens, and a detector. The first prism disperses sharply in the near-infrared (NIR) range along the vertical direction, and it is relatively non-dispersive in the mid-wave infrared (MWIR) range. The second prism is substantially more dispersive in the MWIR range than in the NIR range along the horizontal direction. The beam deviation caused by the first and second prisms can be controlled by the third prism. The IBSIS yields a two-dimensional dispersion pattern (TDP). The formulas and numerical simulation of the TDP are presented. The methods of target location calculation and spectral signature extraction are described. The IBSIS can locate multiple targets using only one frame of data, which allows for real-time detection and measurement of the energetic targets.展开更多
Metasurface is a new kind of 2D metamaterial that is able to manage a variety of light beam modulations through steering the phase of the scattering waves. In this work, we utilize the metasurface to manipulate the li...Metasurface is a new kind of 2D metamaterial that is able to manage a variety of light beam modulations through steering the phase of the scattering waves. In this work, we utilize the metasurface to manipulate the light beam in the mid-infrared regime. By using the metallic rod and the plate structure, the metasurface presents a high polarization conversion efficiency and a wide working bandwidth. With specially rotated metallic rods, the meta- surface can realize various light beam manipulations, such as negative reflection, beam collimation, and focusing. All of these results show that such a metasurface will have potential applications in future mid-infrared optics.展开更多
Dynamic infrared scene simulation is for discovering and solving the problems encountered in designing, developing and manufacturing infrared imaging guidance weapons. The infrared scene simulation is explored by usin...Dynamic infrared scene simulation is for discovering and solving the problems encountered in designing, developing and manufacturing infrared imaging guidance weapons. The infrared scene simulation is explored by using the digital grayscale modulation method. The infrared image modulation model of a digital micro-mirror device (DMD) is established and then the infrared scene simulator prototype which is based on DMD grayscale modulation is developed. To evaluate its main parameters such as resolution, contrast, minimum temperature difference, gray scale, various DMD subsystems such as signal decoding, image normalization, synchronization drive, pulse width modulation (PWM) and DMD chips are designed. The infrared scene simulator is tested on a certain infrared missile seeker. The test results show preliminarily that the infrared scene simulator has high gray scale, small geometrical distortion and highly resolvable imaging resolution and contrast and yields high-fidelity images, thus being able to meet the requirements for the infrared scene simulation inside a laboratory.展开更多
A problem in terms of the accuracy of noninvasive measurement of blood glucose with near-infrared(NIR) spectroscopy is mainly caused by the weak glucose signal and strong background variations.We report the existenc...A problem in terms of the accuracy of noninvasive measurement of blood glucose with near-infrared(NIR) spectroscopy is mainly caused by the weak glucose signal and strong background variations.We report the existence of the radial reference point in a floating-reference method,which is supposed to solve this problem.Based on the analysis of the infinite diffusion theory,the local condition of the reference point is deduced theoretically.Then the experiments using the intralipid solutions are constructed to testify the existence of the reference point.In order to further validate our results,Monte Carlo simulations are performed to calculate the diffused light distribution according to the variation of the glucose concentration in the intralipid solutions.All the reference points existing in three-layer skin model are also listed at the wavelength of 1200-1700 nm.展开更多
The tunable multiple plasmon-induced transparency (PIT) effect is investigated numerically in a metal-insulator-metal (MIM) waveguide with three side-coupled rectangular resonators. The system exhibits dual-mode P...The tunable multiple plasmon-induced transparency (PIT) effect is investigated numerically in a metal-insulator-metal (MIM) waveguide with three side-coupled rectangular resonators. The system exhibits dual-mode PIT effects in the visible and near-infrared regions. By adjusting the geometrical parameters of the structure, we can manipulate not only each single PIT window, but also the double PIT windows simulta- neously. Our structures may have potential applications for optical communication, integrated optics, and optical information processing. The finite element method (FEM) illustrates our theoretical design.展开更多
We report the experimental demonstration of transform-limited sub-6 fs pulses at an optimal central wavelength by a tunable noncollinear optical parametric amplification(NOPA) source. Meanwhile, a white light contin...We report the experimental demonstration of transform-limited sub-6 fs pulses at an optimal central wavelength by a tunable noncollinear optical parametric amplification(NOPA) source. Meanwhile, a white light continuum in the near-infrared(NIR) range from 900 to 1100 nm is also successfully generated by focusing the unconverted800 nm beam during NOPA generation on a sapphire rod. Both visible-pump/visible-probe and visible-pump/NIR-probe experiments are realized using the same laser system. As examples, ultrafast photo-induced exciton dynamics inside two kinds of materials are investigated by the visible-pump/visible-probe and visible-pump/NIR-probe spectroscopy, respectively.展开更多
The effects of bismuth doping content and temperature on the absorption property and near-infrared (NIR) luminescence of Bi-doped La2O3-Al2O3-SiO2 (LAS) glasses are presented. The emission intensity reaches the ma...The effects of bismuth doping content and temperature on the absorption property and near-infrared (NIR) luminescence of Bi-doped La2O3-Al2O3-SiO2 (LAS) glasses are presented. The emission intensity reaches the maximum when the Bi2O3 content in 3.0Bi-LAS is 1.83%. The emission spectra reach their peaks at 1 190 and 1 117 nm, with full-width at half-maximum (FWHM) values of 330 and 228 nm under 500 and 700-nm excitations, respectively. As the Bi203 content increases, the peak wavelengths and FWHMs of emission bands increase, but their lifetimes decrease. The lifetime of 2.0Bi-LAS is 460 μs at 9 K, and is almost temperature independent until 350 K. The NIR emission of Bi in the system has strong resistance to thermal quenching from 9 to 350 K.展开更多
The Raman spectra from leukemic cell line (HL60) and normal human peripheral blood mononuclear cells (PBMCs) are obtained by confocal micro-Raman spectroscopy using near-infrared laser (785 nm) excitation. The s...The Raman spectra from leukemic cell line (HL60) and normal human peripheral blood mononuclear cells (PBMCs) are obtained by confocal micro-Raman spectroscopy using near-infrared laser (785 nm) excitation. The scanning range is from 500 to 2000 cm^-1. The two average Raman spectra of normal PBMCs and carcinoma cells have clear differences because their structure and amount of nucleic acid, protein, and other major molecules are changed. The spectra are also compared and analyzed by principal component analysis (PCA) to demonstrate the two distinct clusters of normal and transformed cells. The sensitivity of this technique for identifying transformed cells is 100%.展开更多
基金supported by the Hundred Talents Program of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(Nos.61475171 and 61177083)+1 种基金the Pujiang Talent Plan(No.14PJ1409200)the Joint Research Project of Chinese Academy of Science and Japan Society for the Promotion of Science(No.GJHZ1412)
文摘We report an Er3+-doped fluorogallate glass with good thermal and chemical stability. The low maximum phonon energy and high mid-infrared (IR) transmittance of the glass are confirmed by Raman and IR spectra, respectively. Based on Judd-Ofelt theory, intensity parameters and radiative properties are determined from the absorption and emission spectra. The proposed glass possesses a large fluorescence branching ratio β (21.71%) and a maximum stimulated emission cross-section σem of Er3+:4 I11/2 → 4 I13/2 transition at 2.71 μm (1.04 × 10^-20 cm2). The results indicate that it can be potentially applied in high-power 2.7 μm fiber lasers.
基金supported by the International Science and Technology Cooperation Program of China(ISTCP) (No.2014DFT50230)the National Key Scientific Instrument and Equipment Development Project (No.2011YQ030127)the National Natural Science Foundation of China(No.61405133)
文摘We demonstrate an efficiency-enhanced picosecond (ps) mid-infrared radiation via optical parametric downconversion. Based on a cascaded periodically poled MgO-doped stoiehiometric lithium tantalate crystal (MgO:sPPLT), a tandem optical parametric oscillation-optical parametric amplification (OPO-OPA) process is achieved. Compared with a single OPO process, the conversion efficiency obtains an enhancement of 71%.
基金supported by the National Natural Science Foundation of China(Nos.41666004,41576033,and 61465009)the Graduate Student Innovation Foundation of Jiangxi Province(No.YC2015-S331)
文摘The scattering properties of ZnO nanospheres with four different particle diameters of 10, 50, 100, and 200 nm suspended in water are investigated theoretical and experimentally in the spectral range of the entire visible range and part of the near-infrared region. The scattering properties of ZnO nanospheres suspended in water are described by employing three main parameters: the angular distribution of the scattering intensity I, the scattering extinction coefficient ascat, and the scattering cross section ascat. The results indicate that (i) at a certain wavelength, the angular distribution of the scattering intensity appears as an obviously forward- propagating feature, and the forward-scattering intensity is dominant gradually when the particle diameter in- creases from 10 to 200 nm, and (ii) the scattering extinction coefficient and cross section can be determined by using the measured transmittance changes of a pure water sample and a given ZnO sample; they all are shown to be dependent on the particle size and incident wavelength. The experimental results of four different scattering samples agree well with the theoretical predictions within the given wavelength range.
基金supported by the National "863" Program of China (No. 2009AA122101)the National Natural Science Foundation of China (Nos. 40871160and 60841006)
文摘Retrieving snow surface reflectance is difficult in optical remote sensing. Hence, this letter evaluates five surface reflectance models, including the Ross-Li, Roujean, Walthall, modified Rahman and Staylor models, in terms of their capacities to capture snow reflectance signatures using ground measurements in Antarctica. The biases of all the models are less than 0.0003 in both visible and near-infrared regions. Moreover, with the exception of the Staylor model, all models have root-mean-square errors of around 0.02, indicating that they can simulate the reflectance magnitude well. The R2 performances of the Ross-Li and Roujean models are higher than those of the others, indicating that these two models can capture the angle distribution of snow surface reflectance better.
基金supported by the National Natural Science Foundation of China(No.61178060)the Program for New Century Excellent Talents in University(No.NCET-10-0552)+1 种基金the Independent Innovation Foundation of Shandong University(No.2012TS215)the Natural Science Foundation for Distinguished Young Scholar of Shandong Province(No.2012JQ18)
文摘The steady-state stimulated Raman scattering (SRS) gain with different excitation wavelengths ranging from 400 to 1100 nm of tungstate crystals, SrWO4 and BaWO4, is systematically researched. As excitation frequency is close to electronic transition frequency, molecular polarizability is not a constant, which has to be taken into account in our work. The experiment and theory agree well with each other and show that SRS gain is not only proportional to Stokes light frequency, but is also inversely proportional to biquadratic excitation frequency.
文摘Bi-doped SiO2-Al2O3-GeO2 fiber preforms are prepared by modified chemical vapor deposition (MCVD) and solution doping process. The characteristic spectra of the preforms and fibers are experimentally investigated, and a distinct difference in emission between the two is observed. Under 808-nm excitation, an ultra-broad near-infrared (NIR) emission with full-width at half-maximum (FWHM) of 495 nm is observed in the Bi-doped fiber. This observation, to our knowledge, is the first in this field. The NIR emission consists of two bands, which may be ascribed to the Bi0 and Bi+ species, respectively. This Bi-doDed fiber is promising for broadband or)tical amolification and widely tunable laser.
基金supported by the Doctoral Foundation of Dalian University of Technology (No.3005-893327)the National Natural Science Foundation of China (No.60807009)the Young Teacher Foundation of Dalian University of Technology (No.3005-893212)
文摘We demonstrate the near-infrared (NIR) organic light-emitting devices (OLEDs) based on copper hexade-cafluorophthalocyanine (CuPcF16) doped into 2,2,2”-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzimidazole] (TPBI). The device structure is ITO/ NPB/ TPBI:CuPcF16/BCP/Alq3/Al. Room-temperature electro- luminescence is observed at about 1106 nm due to transitions from the first excited triplet state to the ground state (T1-S0) of CuPcF16. The result indicates that FSrster and Dexter energy transfers play a minor role in these devices, while the direct charge trapping is the dominant mechanism. The absorption spectra of CuPeF16 solution in pyridine and vacuum sublimed films on quartz have also been investigated.
基金supported by the National 973 Program of China(No.2013CB632704)the National Natural Science Foundation of China(No.11374357)
文摘High-sensitivity and broad bandwidth photo-detector devices are important for both fundamental studies and high-technology applications. Here, by using three-dimensional (3D) finite-difference time-domain simulation, we design an optimized 3D multi-layer gold nano-antenna to enhance the near-infrared (NIR) absorption of germanium nanoparticles. The key ingredient is the simultaneous presence of multiple plasmonic resonance modes with strong light-harvesting effect that encompass a broad bandwidth of germanium absorption band. The simulation results show more than two orders of magnitude enhanced absorption efficiency of gernanium around 1550 nm. The design opens up a promising way to build high-sensitivity and broad bandwidth NIR photo-detectors.
基金supported by the National Natural Science Foundation of China(No.51175436)the Aeronautical Science Foundation of China(No.2012ZC53036)+1 种基金the Northwestern Polytechnical University Foundation for Fundamental Research(No.NPU-FFR-JC200811)the 111 Projects from Chinese Ministry of Education(No.B13044)
文摘The emerging perfect-absorber metamaterials (PAMs) provide an alternative material approach for the next generation of electromagnetic detection at any frequency band of interest. One type of dual cross-shaped PAMs is developed to obtain multiplex-band spectrum absorption at mid-infrared region. Three distinct absorption peaks are attributed to the polarization sensitivity excitation of the plasmonic resonance. The charge density distributions, which are excited by resonant electromagnetic waves passing through the PAMs medium, provide insights into the observed absorption behavior. We find that the retrieved optical properties of the PAMs including permittivity and permeability are still consistent with the sum of the Drude and Lorentz type models at wavelengths ranging from 2.0 to 10.0μm. Such multiplex-band absorption properties enable the proposed PAMs a powerful tool for the direct detection of multiple molecular vibrational structures, and for multiple spectra infrared detection.
基金This work was supported partly by the National Natural Science Foundation of China(Nos.60578057 and 60878062)the Natural Science Foundation of Fujian Province(No.2008J0317)the Project WKJ2008-2-035 supported by the Science Research Foundation of Ministry of Health&United Fujian Provincial Health and Education Project for Tackling the Key Research.
文摘The feasibility of fenestration operation in middle ear bone with pulsed infrared laser is evaluated. Healthy male New Zealand rabbits in vivo are used in the experiment. Middle ear mastoid bone of animal model is completely exposed with conventional methods, and then a pulsed CO2 laser (10.6 μm) and an Er:YAG laser (2.94 μm) are used to perform the fenestration operation. Diamond drill is also used as a control group. The total operation time and light irradiation time are recorded and the opening efficiency is assessed. The morphological changes and thermal damage around the opening window on the middle ear bone are examined. It is shown that both laser systems are suitable for the fenestration operation in middle ear bone, and this no-touch technique has a lot of benefits compared with traditional methods. The bleeding during operation has an important effect on operation time and thermal injury and needs to be controlled efficiently in further study.
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.
基金supported by the National Natural Science Foundation of China(Nos.11127901,61221064,60921004,11134010,1122790211222439,11274325,11404356,61108012,and 11474223)+4 种基金the National973 Project of China(No.2011CB808103)the Zhejiang Provincial Natural Science Foundation of China(No.LY14F050008)the Shanghai Commission of Scienceand Technology Yangfan Project(No.14YF1406000)the Shanghai Institute of Optics and Fine Mechanics Specialized Research Fund(No.1401561J00)the Open Fund of the State Key Laboratory of High Field Laser Physics
文摘We theoretically investigate multiple electron rescatterings in high-order harmonic generation with a wide range of driving laser wavelengths. In order to obtain a clear and intuitive insight, the time-frequency analysis of the dipole acceleration calculated by the numerical solution of the time-dependent SchrSdinger equation is per- formed and compared with the classical electron trajectory calculation. The result shows that in the mid-infrared regime, the high-order electron trajectory associated with multiple rescatterings plays a more important role than the usually referred-to "long and "short" electron trajectories. To provide quantitative evidence, the strong-field approximation is used to calculate the yield ratio of the high-order harmonic generation from the first rescattering and the multiple rescatterings.
基金supported by the Fundamental Research Funds for the Central Universities under GrantNo.K5051305003
文摘A compact static infrared broadband snapshot imaging spectrometer (IBSIS) is presented. It consists of a telescope, three prisms, a focusing lens, and a detector. The first prism disperses sharply in the near-infrared (NIR) range along the vertical direction, and it is relatively non-dispersive in the mid-wave infrared (MWIR) range. The second prism is substantially more dispersive in the MWIR range than in the NIR range along the horizontal direction. The beam deviation caused by the first and second prisms can be controlled by the third prism. The IBSIS yields a two-dimensional dispersion pattern (TDP). The formulas and numerical simulation of the TDP are presented. The methods of target location calculation and spectral signature extraction are described. The IBSIS can locate multiple targets using only one frame of data, which allows for real-time detection and measurement of the energetic targets.
基金supported by the National "973" Program of China(No.2012CB933501)the Program of "The Invention of the China Academy of Space Technology"
文摘Metasurface is a new kind of 2D metamaterial that is able to manage a variety of light beam modulations through steering the phase of the scattering waves. In this work, we utilize the metasurface to manipulate the light beam in the mid-infrared regime. By using the metallic rod and the plate structure, the metasurface presents a high polarization conversion efficiency and a wide working bandwidth. With specially rotated metallic rods, the meta- surface can realize various light beam manipulations, such as negative reflection, beam collimation, and focusing. All of these results show that such a metasurface will have potential applications in future mid-infrared optics.
基金co-supported by China Postdoctoral Science Foundation (20090461314)
文摘Dynamic infrared scene simulation is for discovering and solving the problems encountered in designing, developing and manufacturing infrared imaging guidance weapons. The infrared scene simulation is explored by using the digital grayscale modulation method. The infrared image modulation model of a digital micro-mirror device (DMD) is established and then the infrared scene simulator prototype which is based on DMD grayscale modulation is developed. To evaluate its main parameters such as resolution, contrast, minimum temperature difference, gray scale, various DMD subsystems such as signal decoding, image normalization, synchronization drive, pulse width modulation (PWM) and DMD chips are designed. The infrared scene simulator is tested on a certain infrared missile seeker. The test results show preliminarily that the infrared scene simulator has high gray scale, small geometrical distortion and highly resolvable imaging resolution and contrast and yields high-fidelity images, thus being able to meet the requirements for the infrared scene simulation inside a laboratory.
基金supported by the"111"Project of China (No.B07014)the National Natural Science Foundation of China(Nos.30600126,30700168,and 60938002)and the Research Fund for the Doctoral Program of Higher Education of China(No.20070056069)
文摘A problem in terms of the accuracy of noninvasive measurement of blood glucose with near-infrared(NIR) spectroscopy is mainly caused by the weak glucose signal and strong background variations.We report the existence of the radial reference point in a floating-reference method,which is supposed to solve this problem.Based on the analysis of the infinite diffusion theory,the local condition of the reference point is deduced theoretically.Then the experiments using the intralipid solutions are constructed to testify the existence of the reference point.In order to further validate our results,Monte Carlo simulations are performed to calculate the diffused light distribution according to the variation of the glucose concentration in the intralipid solutions.All the reference points existing in three-layer skin model are also listed at the wavelength of 1200-1700 nm.
基金supported by the National Natural Science Foundation of China(Nos.51506184,51172194,11504139,and 11447149)the Natural Science Foundation of Jiangsu Province of China(No.BK20140167)the Nature Science Foundation of Xuzhou Institute of Technology(No.XKY2014206)
文摘The tunable multiple plasmon-induced transparency (PIT) effect is investigated numerically in a metal-insulator-metal (MIM) waveguide with three side-coupled rectangular resonators. The system exhibits dual-mode PIT effects in the visible and near-infrared regions. By adjusting the geometrical parameters of the structure, we can manipulate not only each single PIT window, but also the double PIT windows simulta- neously. Our structures may have potential applications for optical communication, integrated optics, and optical information processing. The finite element method (FEM) illustrates our theoretical design.
基金partly financially supported by the 100 Talents Program of CASthe National Basic Research Program of China(Grant No.2011CB808101)the National Natural Science Foundation of China(Grant No.61475169,61221064)
文摘We report the experimental demonstration of transform-limited sub-6 fs pulses at an optimal central wavelength by a tunable noncollinear optical parametric amplification(NOPA) source. Meanwhile, a white light continuum in the near-infrared(NIR) range from 900 to 1100 nm is also successfully generated by focusing the unconverted800 nm beam during NOPA generation on a sapphire rod. Both visible-pump/visible-probe and visible-pump/NIR-probe experiments are realized using the same laser system. As examples, ultrafast photo-induced exciton dynamics inside two kinds of materials are investigated by the visible-pump/visible-probe and visible-pump/NIR-probe spectroscopy, respectively.
基金supported by the National Natural Science Foundation of China(Nos.60937003 and 61111120100)
文摘The effects of bismuth doping content and temperature on the absorption property and near-infrared (NIR) luminescence of Bi-doped La2O3-Al2O3-SiO2 (LAS) glasses are presented. The emission intensity reaches the maximum when the Bi2O3 content in 3.0Bi-LAS is 1.83%. The emission spectra reach their peaks at 1 190 and 1 117 nm, with full-width at half-maximum (FWHM) values of 330 and 228 nm under 500 and 700-nm excitations, respectively. As the Bi203 content increases, the peak wavelengths and FWHMs of emission bands increase, but their lifetimes decrease. The lifetime of 2.0Bi-LAS is 460 μs at 9 K, and is almost temperature independent until 350 K. The NIR emission of Bi in the system has strong resistance to thermal quenching from 9 to 350 K.
基金supported by the National Natural Science Foundation of China(No.60778046,60711120031)the Natural Science Foundation of Fujian Province(No.A0740010,2007J0318)
文摘The Raman spectra from leukemic cell line (HL60) and normal human peripheral blood mononuclear cells (PBMCs) are obtained by confocal micro-Raman spectroscopy using near-infrared laser (785 nm) excitation. The scanning range is from 500 to 2000 cm^-1. The two average Raman spectra of normal PBMCs and carcinoma cells have clear differences because their structure and amount of nucleic acid, protein, and other major molecules are changed. The spectra are also compared and analyzed by principal component analysis (PCA) to demonstrate the two distinct clusters of normal and transformed cells. The sensitivity of this technique for identifying transformed cells is 100%.