Broadband Infrared Luminescence from Bismuth-Doped GeS2--Ga2S3 Chalcogenide Glasses

Near-infrared luminescence is observed from bismuth-doped GeS2-Ga2Sa chalcogenide glasses excited by an 808 nm laser diode. The emission peak with a maximum at about 1260 nm is observed in 80GeS2-2OGa2 Sa：O.fBi glass and it shifts toward the long wavelength with the addition of Bi gradually. The full width of half maximum （FWHM） is about 200 nm. The broadband infrared luminescence of Bi-doped GeS2-Ga2Sa chalcogenide glasses may be predominantly originated from the low valence state of Bi, such as Bi＋. Raman scattering is also conducted to claxify the structure of glasses. These Bi-doped GeS2 Ga2Sa chalcogenide glasses can be applied potentially in novel broadband optical fibre amplifiers and broadly tunable laser in optical communication system.     

Fluorescence Emission Centres and the Corresponding Infrared Fluorescence Saturation in a Bismuth-Doped Silica Fibre

We investigate the fluorescence characteristics of bismuth doped silica fibres with and without A1 co-dopant which are fabricated by means of modified chemical vapour deposition （MCVD） technique, and find that the fluorescences in the red region （centred around 750nm） and in the infrared region （centred around llOOnm） may originate from different emission sites in the fibre. Strong upconversion phenomena are observed in both Al-codoped and non A1 codoped bismuth fibres when the fibres are excited by an acoustic-optic Q-switched Nd：YVO4 laser. Both the aspects indicate that the upper energy level absorption reported in the work of the bismuth doped silica fibre lasers may result from the fluorescence emission sites that are not responsible for the infrared emission. It is thus expected that optimizing the compositions and the fabrication conditions of the fibre and then transferring more fluorescence emission centres are helpful for the infrared emission.     

热释电红外传感器在无线遥控报警系统中的应用

热释电红外探测无线遥控报警系统由热释电红外探测模块、无线电收/发射模块、数字编/译码集成电路和语音录放模块组成。当人体进入监视区时,红外传感器首先将接收到的红外辐射能转换成电能信号,再经内部电路放大处理,输出控制信号启动发射系统工作,经编码脉冲调制后, 由发射模块向空间辐射无线电遥控编码信号;接收机收到信号后,便进行解调、放大、整形,从解码器输出编码脉冲,然后触发语音录放系统,播放事先录制好的警示语,提醒值班人员。该系统主要采用了RDP-18热释电红外探测模块,具有从信号接收至控制输出的全部功能。整体装置为模块化结构,具有频率稳定、工作可靠、免调试等特点,遥控距离1 000 m,可适用于多种场合的需要。     

ANALYTICAL SOLUTION FOR RESPONSE OF FERROELECTRIC THIN FILM TO INFRARED RADIATION

Micro-bolometer pixel is an essential element in the infrared focal plane array(IRFPA) of infrared detectors.Its response to infrared radiation is analyzed in this paper.The pixel structure is modeled as a composite laminate thin plate whose sides are measured with the thickness from 0.1-1 μm.Its middle ply is a ferroelectric thin film.Its top surface is covered with a gold or platinum infrared absorber,while the bottom surface is deposited with platinum or lanthanum-nickel.Meanwhile both surfaces are a pair of electrodes.The top surface receives infrared radiation pulses successively.For the very tiny micro bolometer pixel,it is assumed that the infrared radiation is uniformly distributed on the plate.Furthermore,as the ratio of the side length to the thickness of the plate is dramatically large,it is assumed that heat transfer only takes place across the thickness of the plate.The thermal-electric-mechanical coupling governing equations are solved in a form of Fourier series.Results of the displacement,temperature variation and electric output signals of the micro bolometer pixel structure under infrared radiation are obtained,analyzed and compared with experimental data.     

红外技术的物理基础及其军事应用

本文介绍了红外技术的物理基础及其在军事领域的主要应用 .     

Studies on the Effect of Structure to Property Stability of Glucomannan

1 INTRODUCTION Directive action of hydrogen bond paves the way for new fields of biological activity, molecular re- cognition and crystal engineering[1]. Hydrogen bond plays an important role in the physical and chemical properties, such as melting point, boiling point, solu- bility, acid strength, viscosity and hardness degree[2]. At present, the popular tools used to investigate hy- drogen bond include wet melting point method, chromatography analysis method, spectrum method and diffract…     

IrDA编解码电路的HDL设计与后仿真

随着无线通信技术的发展,红外线数据传输技术得到了越来越多的应用,因此迫切需要一种高效的设计与仿真方法．在IrDA协议组技术规范的基础上,提出一种基于HDL语言的IrDA编码和解码电路的实现方法,并通过后仿真结果与编解码的波形比较,验证了新设计的编解码电路的逻辑功能和时序都符合设计规范的要求．此外,采用HDL语言设计的电路简洁高效,可方便地在可编程逻辑器件中实现,并且在多个嵌入式系统的设计中得到了应用和验证．     

开展可见光—红外线—太赫兹波成像系列实验培养解决真实问题人才

物理学的研究成果有力推动了三次工业革命的发展。进入新世纪以来,量子计算、低维物理、量子探测等现代物理研究成果正在促进第四次工业革命暨工业4.0向纵深发展。笔者在大学物理实验中规划布局多层次物理实验题目,以开展可见光-红外线-太赫兹波探测与成像系列实验为例,介绍了学生深刻理解不同波段的电磁波在新旧产业领域应用性的异同。这一教学模式有利于学生掌握近现代物理成果与实验综合技能,培养他们成为解决新产业领域面临的真实问题的新理工科人才,从容面对新技术革命与职业选择。     

基于红外线传感器的智能测距圆规的设计开发

传统的圆规通常采用人字形结构,先通过直尺量取的方式来确定画圆的半径,进而通过改变角度来实现画圆,二次量取和旋转圆规脚都会增大数据的误差,且给使用者带来诸多不便.本研究经深入调研和实践,在传统的圆规基础上进行创新,通过红外线传感测距来取代传统圆规通过直尺量取直径的方式,并采用滑动式改变直径,消除了传统圆规因频繁变化角度导...     

奇异水世界

美国哈勃太空望远镜的数据分析显示,40光年外存在一颗被厚重蒸汽大气层包裹的行星,该行星距其环绕的红矮星很近.这颗编号为GJ1214b的行星最早发现于2009年,估计其表面温度为230℃,最初认为其朦胧的大气层是因影像模糊造成的.但是最新观测却表明其大气层的主要成分是水蒸气,因为朦胧的大气层能够更多地透射红外线而不是可见光.