近红外镜头系统的设计与装调

为了使1.23 m望远镜具有大视场捕获功能,进行了口径为200 mm的近红外镜头的设计与装调工作。首先,通过光学原理确定同轴反射式光学系统。其次,通过有限元分析方法对比桁架式与圆筒式主支撑结构、三翼梁与四翼梁式次镜支撑结构在不同工况下的变形,确定桁架式三翼梁支撑结构。最后通过设计适当的次镜装调结构和选用适当的CCD电控平移台,对系统进行装调。装调后对系统进行检测实验,检测得到系统波前误差RMS=0.106 18λ,PV=0.553 62λ(λ=632 nm)。检测结果表明该近红外镜头足够满足光学设计要求及成像要求。

原位光谱法研究聚合物/CO_2系统-吸着、溶胀以及溶解度

对聚合物/CO2系统中的吸着、溶胀的原位光谱研究,以及挥分在超临界二氧化碳中溶解度的原位光谱检测技术的方法原理和研究现状进行了综述。并力图将原位光谱法应用于检测挥分(EG)在超临界二氧化碳中的溶解度。

Two-color laser wavelength effect on intense terahertz generation in air

Near-IR femtosecond lasers have been proposed to produce high-field terahertz radiation in the air via the laser-plasma interaction, but the physical mechanism still needs to be further explored. In this work, we theoretically investigate the effect of the two-color laser wavelength on the terahertz generation in the air based on a transient photocurrent model.We show that the long wavelength laser excitation can greatly enhance the terahertz amplitude for a given total laser intensity. Furthermore, we utilize a local current model to illustrate the enhancement mechanism. Our analysis shows that the terahertz amplitude is determined by the superposition of contributions from individual ionization events, and for the long wavelength laser excitation, the electron production concentrates in a few ionization events and acquires the larger drift velocities, which results in the stronger terahertz radiation generation. These results will be very helpful for understanding the terahertz generation process and optimizing the terahertz output.

C2H2 Overtones Near 12300 cm^-1 Revisited with a Very Sensitive Cavity Ring-down Spectrometer

A cavity ring-down spectrometer （CRDS） is constructed with a single-mode continuous-wave Ti：Sapphire laser. It allows attaining a minimum detectable absorption of 1.8× 10^-10cm^-1. The spectrometer is applied to record the overtone spectrum of ^12C2H2 in the 12240- 12350 cm-1. Compared with the previous CRDS and intra-cavity laser absorption spectroscopy studies in the same region, the present measurement achieved better sensitivity and better precision as well. As a result, the ro-vibrational parameters of the high overtone bands of acetylene at 12290.12, 12311.82, and 12350.61 cm^-1 have been refined. The advantages of the present CRD spectrometer is also demonstrated by the newly observed and well characterized perturbation on the f component of the very weak band near 12289 cm^-1. The quantitative measurement capability of the spectrometer is verified with the measurement of the water lines and employed to give the absolute band intensities of those three acetylene bands.

近红外荧光探针和成像系统临床转化应用的初步探索

目的围绕近红外荧光成像探针、成像系统和临床转化评价开展探索,为进一步研发和应用提供依据。方法应用FDA批准的吲哚菁绿(ICG)评价近红外成像在复杂创面伤情评估中的价值,应用课题组前期发现的具有肿瘤靶向特性的近红外染料IR-780评价其在外科手术切除肿瘤组织及淋巴结成像中的意义。通过对IR-780的动物体内成像实验对课题组协作研发的近红外荧光成像系统进行评价。结果应用ICG能够清晰实现糖尿病足和烧伤手指的血管成像,反映血液供应情况,对于评判血管闭塞程度和指导手术治疗具有潜在应用价值;应用IR-780能够实现对手术切除肿瘤病灶的识别及淋巴结显影,初步显示出潜在转化应用前景;通过对IR-780的动物成像研究显示,协作研发的近红外成像系统TPS-785-Ⅲ具有良好的成像功能,为后续开发奠定基础。结论近红外荧光成像显示出良好的临床应用前景,通过对近红外荧光探针和成像系统的进一步研究评价,可望为临床诊断治疗提供新的手段。

Nanocrystal-enhanced near-IR emission in the bismuth-doped chalcogenide glasses

Bismuth （Bi）-doped materials have attracted a great deal of attention because of their broadband near- infrared （near-IR） emission around the wavelength utilized in telecommunications. In this study, broad near-IR emission band from 1100 to 1650 nm is generated in the Bi-doped 90GeS2-10Ga2S3 glass and glass-ceramics under 820 nm of light excitation. Based on the analysis of the absorption and emission spectra, the origin of this broadband emission is ascribed to the Bi22- dimers. The precipitation of β-GeS2 nanocrystals drastically enhances the emission intensity and lifetime of Bi-doped chalcogenide glass,

基于垂直层叠结构的可见/近红外双波段传感器研究

提出了基于垂直层叠结构的双波段传感器,该结构为同时对可见波段和近红外波段进行成像提供了可能。它的基本原理是利用不同波长的光在硅材料中穿透深度的非线性分布,即：短波长的可见光主要在表面被吸收,长波长的近红外光则主要在更深的位置被吸收。通过垂直层叠结构,抽取不同深度的光生载流子,即可以得到相应波段的成像信息。数值仿真分析表明,结构参量为D1=2μm,D2=18μm的结构能在400-1200 nm波长范围得到响应峰值波长为550 nm和1000 nm的最佳可见/近红外响应。