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Modeling visible and near-infrared snow surface reflectance-simulation and validation

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Chinese Optics Letters 2011年第10期9卷 79-81页

作者：吴宏伊童玲 Institute of Geo-Spatial Information Science and Technology University of Electronic Science and Technology of China

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.

关键词： infrared devices Remote sensing Snow

Fabrication of air-bridged Kerr nonlinear polymer photonic crystal slab structures in near-infrared region

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Chinese Optics Letters 2012年第11期10卷 74-76页

作者：蒙自明钟晓岚王晨李志远 Laboratory of Optical Physics Institute of PhysicsChinese Academy of Sciences

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.

关键词： Finite difference time domain method infrared devices Optical data processing Photonic crystals Scanning electron microscopy Time domain analysis Wet etching

Highly enhanced broadband infrared absorption of germanium by multi-layer plasmonic nano-antenna

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Chinese Optics Letters 2014年第9期12卷 75-78页

作者：钟晓岚刘菊李志远 Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Department of Electrical and Computer Engineering National University of Singapore

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.

关键词： Antennas Bandwidth Finite difference time domain method infrared devices Light absorption Photodetectors Plasmons Time domain analysis

Fenestration operation in middle ear bone with pulsed infrared lasers: an in-vivo study

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Chinese Optics Letters 2009年第9期7卷 830-833页

作者：张先增王晓燕詹振林叶青谢树森 Institute of Laser and Optoelectronics Technology Fujian Provincial Key Laboratory for Photonics TechnologyKey Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of EducationFujian Normal University Department of Otolaryngology Fujian Provincial Hospital Provincial Clinical College of Fujian Medical University Institute of Laser and Optoelectronics Technology Fhjian Provincial Key Laboratory for Photonics TechnologyKey Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of EducationFujian Normal University

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.

关键词： Bone Erbium infrared devices Pulsed laser applications

Polarization sensitivity contributes to multiple band spectra of one mid-infrared absorber

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Chinese Optics Letters 2014年第10期12卷 86-90页

作者：黎永前王斌斌许小轮苏磊 Key Laboratory of Micro/Nano Systems for Aerospace of Ministry of Education Northwestern Polytechnical University

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.

关键词： Electromagnetic waves Frequency bands infrared devices Multiplexing Optical properties Polarization

Steady-state Raman gain in visible and near-infrared waveband of Sr WO_4 and Ba WO_4 crystals

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Chinese Optics Letters 2014年第12期12卷 114-116页

作者：张芳张清华王波胡大伟于浩海张怀金王正平许心光 State Key Laboratory of Crystal Materials Shandong University Key Laboratory of Functional Crystal Materials and Device Shandong UniversityMinistry of Education Chengdu Fine Optical Engineering Research Center Institute of Science Technology for National Defense Shandong University

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.

关键词： Excited states infrared devices

Static light scattering properties of a ZnO nanosphere aqueous suspension at visible and near-infrared wavelengths

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Chinese Optics Letters 2017年第1期15卷 104-109页

作者：武浩鹏史久林严峰杨俊杰张余宝何兴道 Jiangxi Engineering Laboratory for Optoelectronics Testing Technology Nanchang Hangkong University Nanchang 330063 China National Engineering Laboratory for Nondestructive testing and Optoelectric Sensing Technology and Application Nanchang Hangkong University Nanchang 330063 China

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.

关键词： Angular distribution infrared devices Light scattering Nanospheres Particle size Suspensions (fluids) Zinc oxide

Highly efficient mid-infrared metasurface based on metallic rods and plate

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Chinese Optics Letters 2016年第5期14卷 43-46页

作者：孙倩王漱明刘辉祝世宁 Beijing Institute of Space Mechanics and Electricity National Laboratory of Solid State Microstructures and School of Physics Nanjing University Collaborative Innovation Center of Advanced Microstructures

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.

关键词： infrared devices Plates (structural components)

Contribution of multiple electron rescatterings on high-order harmonic generation in the mid-infrared wavelength regime

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Chinese Optics Letters 2016年第3期14卷 1-4页

作者：袁晓龙刘灿东尉鹏飞曾志男李儒新 State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences University of Chinese Academy of Sciences Department of Physics Shaoxing University

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.

关键词： Electrons Harmonic analysis infrared devices Trajectories