板条增益介质波前畸变诊断方法

对波前重构算法中的区域法进行了改进,使其能够应用于板条增益介质的波前畸变诊断。利用该方法对47块Nd: YAG板条增益介质沿厚度方向波前畸变进行测量,指出镀膜和加工等环节对增益介质的波前畸变可能造成的影响。按照波前畸变峰谷（PV）值对测量结果进行了统计,结果表明:增益介质造成的静态波前畸变参差不齐,测量样本中静态畸变PV值最多可达5 m以上,且仅有4.1%的增益介质静态畸变PV值小于1 m。通过选取某些增益介质使之级联,测量其组合波前畸变,发现在系统中使用两块波面互补的增益介质有助于减小系统的静态波前畸变。     

Studies of the g factors and the local structure of the orthorhombic Ni center in KTaO3 crystal

The local structure and the g factor (g_x, g_y, and g_z) of the Ni⁺ center in KTaO₃ are theoretically studied using the perturbation formulas of the g factors for a 3d⁹ ion in orthorhombically elongated octahedra. The orthorhombic field parameters are determined from the superposition model and the local geometry of the system. In view of the covalency, the contributions from the ligand orbital and spin–orbit coupling interactions are taken into account from the cluster approach. In the calculations, the orthorhombic center is attributed to Ni⁺ occupying the host Ta⁵⁺ site, associated with the nearest-neighboring oxygen vacancy V_O along the c-axis. Furthermore, the planar Ni⁺–O²⁻ bonds are found to experience the relative variation ΔR (≈0.076 Å) along the a- and b-axis, respectively, due to the Jahn–Teller effect and the size mismatching substitution of Ta⁵⁺ by Ni⁺. Meanwhile, the effectively positive V_O can make the central Ni⁺ displace away from V_O along the c-axis by about 0.20 Å. The calculated g factors based on the above local distortions show good agreement with the experimental data.     

Coupling coefficients evaluation of a directional coupler using gain guided and index antiguided fibers

In this paper, we have investigated the mutual and self coupling characteristics of directional couplers using two individual gain guided and index antiguided fibers, which can deliver robust single mode operation with large mode area, respectively owing to the combined adequately large gain coefficients in the core; Some interesting and distinguishing properties from conventional index guided fiber couplers are obtained that: The variations of coupling coefficients are complex-valued and spatially damping oscillated, but not exponential-like decreasing as conventional index guided couplers.     

Quantum Routing on Single Photons with Π-Shaped Channels

We propose a single-photon router that is made of three coupled-resonator forming a Π-type waveguide. The two atoms embedded in the two junctions, which have the distance of 2d, are used as quantum switch to control single photons routing. We find that the scattered rate depend on the incident single photons come from either infinite CRWs or semi-infinite CRWs, and the boundary can enhance the transfer rate.

     

基于非平衡光纤干涉仪的窄线宽激光光源跳模实时测试方法

窄线宽激光器随机发生的跳模现象,是影响光学系统稳定的重要因素.激光器线宽窄往往意味着较长的谐振腔和较小的模间隔,从而给跳模的监测带来了难度.本文提出一种基于非平衡光纤干涉仪的窄线宽光源跳模测试方法,该方法将激光器跳模的频率变化转变为干涉仪的相位变化,并通过相位产生载波(PGC)调制解调技术来检测相位信息,从而实现对跳模过程的监测.该方法灵敏度高,能够长时间连续监控,测试效果优于Fabry-Pérot干涉仪,还可在kHz量级上测量窄线宽激光器的线宽,为单纵模窄线宽激光器研究提供有效的测试手段.     

Investigation on activating individual living monocytic U937 cell by interleukin-6 using Raman tweezers

We investigate the activation of living monocytic U937 cells induced by interleukin-6 （IL-6） at the single cell level. We employ home-built Raman tweezers to measure the Raman spectra of living U937 cells with and without IL-6 at the single cell level. Raman peaks of amide III, amide I, DNA backbone, as well as guanine and adenine in U937 cells, change at 1312, 1652, 1090, and 1576 cm ？1 , respectively, shortly after IL-6 is added in the medium. The change is a dynamic temporal process. In the activation process of U937 cells induced by IL-6, the protein signals recover in 20 min, while the nucleic acid signals continue to increase for 20 min. The results reveal that the biochemical cascades of activation in signal transduction induced by IL-6 can be investigated in situ at the single cell level.     

Facile and scalable fabrication engineering of fullerenol nanoparticles by improved alkaline-oxidation approach and its antioxidant potential in maize

A feasible in operation, labor-saving and low-cost one-step technology to fabricate fullerenol nanoparticles (FNPs) up to 10 g in laboratory was developed by improved alkaline-oxidation approach using moderately concentrated sodium hydroxide solution as the hydroxylation agent and o-dichlorobenzene as the solvent. This strategy paves the avenue for industrial-scale bulk production of FNPs. The resulted product, [C₆₀(OH)₂₂·8H₂O]_n, were characterized by various measurements including matrix-assisted laser desorption ionization time-of-flight mass spectrometry, high-resolution ¹H nuclear magnetic resonance spectrometry, Fourier transform infrared spectroscopy, UV-Visible spectrophotometer, thermogravimetric analysis, differential scanning calorimetry, dynamic light scattering analysis, scanning electron microscopy, and electron spin resonance spectrometer. Radical scavenging assay in vitro confirmed the high efficiency of water-soluble [C₆₀(OH)₂₂·8H₂O]_n as a novel radical scavenger. Furthermore, [C₆₀(OH)₂₂·8H₂O]_n as an excellent candidate has the potential to serve as the plant defense stimulation agent in maize.

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Micromachined Uncooled IR Bolometer Linear Array Using VO2 Thin Films

Mixed vanadium oxide thin films, as VO₂ for the main composition are materials for uncooled microbolometer due to their high temperature coefficient of resistance (TCR) at room temperature. This paper describes the design and fabrication of 8-element linear array IR uncooled microbolometers using the films and micromachining technology. The characteristics of the array is investigated in the spectral region of 8–12 m. The fabricated detectors exhibit responsivity of up to 10 KV/W, typical detectivity of 1.89×10⁸ cmHz^1/2/W, and thermal time constant of 11 ms, at 296 K and at a frequency of 30 Hz. Furthermore, The uncorrected response uniformity of the linear array bolometers is less than 20%.     

F／Cl比与Eu~（2＋）：BaFCl中F色心的浓度和光激励截面的关系

研究了Ｅｕ（２＋）：ＢａＦｘＣｌ２在紫外线辐照下的光激励发光。通过改变激励方式及激励光的扫描方向，给出了Ｅｕ（２＋）：ＢａＦｘＣｌ２－ｘ光激励发光过程中，两种Ｆ色心的浓度比值与光激励截面比值的测定方法。利用这种测定方法，进一步研究了两种Ｆ色心的浓度比值和光激励截面比值与Ｆ／ＣＩ比值的关系。