Study on Refraction Index Sensors Using Fiber Grating F-P Cavity

In this paper, the reflective spectra of a refraction index sensor were analyzed based on fiber grating F-P cavity. The sensor was constituted by two identical fiber gratings. Compared with the refraction index sensor using one fiber grating, the fiber grating F-P cavity sensor has narrower resonant peak and it can be used for more accurate measurement. The resonant peaks in the reflective spectra of the sensor are changed with small changes of the refraction index of the measured chemical liquids or cell samples. So it has potential applications in biology and chemistry.

Structure Design of Disposable Ocean Temperature Depth Sensing Probe Based on F-P Cavity and FBG

The basic principle of sensing is the combination of F-P cavity interference and fiber grating reflection. A hybrid structure sensor probe has been designed based on the combination of an F-P cavity of liquid-filled thermometer structure, and a fiber grating with an elastic diaphragm, herein F-P cavity is used for temperature sensing, and the fiber grating is used for pressure sensing. By adopting the dual optical path structure, the dual-parameter detection of temperature and depth is realized, which solves the problem of low accuracy caused by the cross response of temperature and pressure of a single sensor device and the calculation of the depth information of the ocean with empirical formulas. Compared with traditional sensors, the sensitivity is effectively improved. Theoretical analysis shows that the sensitivity of the F-P cavity with a thermometer structure filled with kerosene reaches 1.334 nm/?C, and the depth sensitivity of the fiber grating is 284.6 pm/Mpa within the ocean depth range of 0 - 400 m.

双组分织物含水率的微波谐振腔法测量技术

针对染整过程中多组分织物含水率准确检测问题,提出了一套基于微波谐振腔法的织物含水率检测系统。首先,基于Bruggeman-Hanai介电混合模型,结合织物结构特征建立了单组分织物含水率与介电常数的关系模型;通过考虑织物厚度与多组分织物组分配比的影响,建立了双组分织物含水率介电常数模型。接着,开展湿度均匀的纯棉、涤纶、混纺织物的介电常数测量实验,采用贝塞尔拟合方法,得到双组分织物介电常数模型的系数,从而获得了不同材质、厚度、组分配比下织物含水率与介电常数的关系模型。通过比较实验织物样品含水率与理论模型预测结果发现,二者吻合较好,均方根误差小于5%,从而验证了双组分织物含水率介电模型的可行性,为后续纺织品含水率检测提供技术支撑。

MEMS F-P干涉型压力传感器

为了满足工业、航天、国防等领域对微型化压力传感器的需求，提出了基于微机电系统（MEMS，Micro electromechanical System）技术制作的非本征型光纤法布里-珀罗（F-P）压力传感器，该传感器传感头由全玻璃材料构成。主要研究了MEMS技术制作全玻璃结构式压力传感器工艺，结合溅射、光刻、腐蚀等工艺在7740 wafer基底上制作出F-P腔体，利用低压化学气相沉积（LPCVD）的方法在基底上沉积一层40 nm的非晶硅作为中间层。通过阳极键合技术在温度400℃下完成玻璃与玻璃的键合，并搭建了该传感器的压力测量平台。实验结果表明：在压力线性范围0-400 kPa内传感器具有很高的重复性，达到0.3%。灵敏度达到1.764 nm/kPa；在传感器使用范围0-80℃内，热敏感系数为0.15 nm/℃。该传感器的研究对设计制作改善了该类传感器的热膨胀失配问题，对低温漂型压力传感器的研究有一定参考价值。

基于F-P腔干涉的膜片式光纤微机电系统压力传感器

基于法布里-帕罗腔的干涉原理,采用微机电系统技术加工制作了一种光纤微机电系统压力传感器.采用浓硼扩散自停止腐蚀和磁控溅射的方法,制备厚度为6μm、机械灵敏度为0.502μm/MPa的传感器敏感膜.基于强度解调技术,利用干涉腔的反射功率与压力的关系对压力进行解调.分析了腔长变化对反射率的影响,确定传感器线性工作点的波长,建立稳定的压力传感测试系统.测试结果表明,该传感器压强最小分辨率为62Pa,灵敏度达到0.51nW/KPa,具有良好的线性度、灵敏度和重复性,适用于人体内压力测量和口腔义齿压力测量.

Vibration insensitive optical ring cavity

The mounting configuration of an optical ring cavity is optimized for vibration insensitivity by finite element analysis. A minimum response to vertical accelerations is found by simulations made for different supporting positions.

新型红外隐身结构材料研究综述

随着军用光电技术的快速发展,隐身技术在现代作战体系中的作用日趋重要,其中,隐身材料对于提高隐身性能至关重要。本文针对红外隐身材料,重点从单波段的红外隐身、多波段兼容的红外隐身、动态的红外隐身三方面综述了国内外红外隐身材料的研究进展,就微纳结构大面积柔性加工方法进行了深入分析。归纳了当前红外隐身材料存在的主要问题,并展望了未来发展趋势。未来,红外隐身材料将向着高强度、大面积、柔性化、智能化的新型结构和材料方向进一步发展,实现高性能的隐身功能。

Investigation on the fabrication of the 3rd harmonic superconducting cavity for the SSRF storage ring

A third harmonic superconducting niobium cavity has been proposed for installation in the Shanghai Synchrotron Radiation Facility （SSRF） storage ring to improve the Touschek lifetime. In order to investigate the feasibility of the superconducting cavity fabrication indigenously and the possibility to master the fabrica tion techniques, cavities were fabricated from copper and niobium sheets by deep drawing and electron-beam welding, and a series of measurements, such as resonant frequency, shape dimensions and wall thickness, were carried out during this process. After analysis of various problems existing in the fabrication process, technique improvements were proposed, and finally the precise shape as designed and resonant frequency within 1.2 MHz were achieved for the new completed cavities. In addition, full annealing was finally proved to be a good cure for niobium sheets＇ tearing up during deep drawing. By fabricating niobium cavities successfully, some problems to the next step were cleared. This paper introduces the process of cavity fabrication and its technique improvements towards forming, and the initial vertical test result of niobium cavity is also presented.

Fabrication of the high power input coupler for BEPCⅡ superconducting cavities

The BEPCII storage ring adopts two 500 MHz superconducting cavities （SCC）. Each one is equipped with a 500 MHz input power coupler. The coupler is to feed 150 kW power in continuous wave （CW） mode with both standing and traveling wave modes. Due to high power feeding and high frequency of the coupler, its fabrication is a big challenge. The fabrication started with two key components, the window and the antenna. Up to now, two sets including windows and antennas have been made by IHEP. And a 270 kW RF power in CW has passed through the coupler during the high power test. The fabrication details are presented in this paper.

UV-LIGA技术在微型模具型腔加工中的应用研究

为了实现微小注射模具型腔的精密加工,针对微小尺度模具型腔的加工难点,通过改良常规UV-LIGA工艺技术,选用合适的基底材料5CrNiMo,采用在基底表面上直接进行电铸生长的无背板生长方法,加工出具有50μm和100μm特征尺寸的哑铃型塑件微型腔.研究结果表明,无背板方法可实现在钢基底表面上直接通过电铸工艺获得微型模具型腔,省去了电铸背板步骤,既简化了工艺过程、缩短了整个工艺的制造周期,又增强了铸层与基底的结合力,可大大提高模具的形状精度.

激光超声检测共焦球面法布里-珀罗干涉仪

从理论上对共焦球面法布里-珀罗干涉仪的自由光谱范围、透射谱线半宽度、精细度、光谱分辨率等光学参数进行了分析,并根据激光超声检测的特点和要求,设计制作了一台实验室用的共焦球面法布里-珀罗干涉仪.利用单片机对该干涉仪的腔长和工作点进行控制,成功实现了激光超声的非接触测量.

系列柱形薄壁腔靶制备工艺研究

为了从实验上深入研究超热电子产生规律，从而减少或抑制超热电子对惯性约束聚变（ＩＣＦ）的危害，我们制备了一系列薄壁腔靶，以供实验研究。本文详细地描述了柱形薄壁腔靶的制备工艺。利用ＮＧ－１０４型精密单向纵切车床，采用金刚石刀具车削，提高心轴质量，表表粗糙度可达０．１μｍ。采用电镀和磁控溅射二种方法镀膜，为了使腔靶壁厚均匀，在镀膜时，必须使心轴匀速旋转。利用磁控溅射在腔靶外表面再涂上１μｍ左右厚的二氧化硅，以提高超薄壁腔靶的强度和自立能力。在腐蚀心轴时，必须仔细控制酸的浓度，防止在腐蚀时因产生气泡太多，太快而使腔靶破裂。用Ｘ射线照相法和扫描电子显微镜测量腔靶的几何参数。制备系列柱形薄壁腔靶达到指标为：壁厚范围２～３０μｍ，壁厚均匀性小于１０％，表面粗糙度０．２～０．３μｍ。最后介绍了在“神光Ⅰ”上打靶结果。结果表明，实验值与理论值符合较好。

碳酸盐岩孔隙分类方法综述

孔隙的分类是系统研究岩石孔隙系统乃至储层研究必不可少的工作。碳酸盐岩孔隙系统复杂,前人按不同的研究目的和生产需要进行不同的分类。碳酸盐岩岩石学家和油气勘探专家常用的是Choquette and P ray的以孔隙是否具有组构选择性为基础的分类。而在油气藏的评价、描述与开发方面,A rch ie按基质结构及孔隙大小的分类、Lucia以岩石结构和岩石物理性质为依据的分类方案,以及Lφnφy以提高孔隙度-渗透率相关关系为目标的分类,应用广泛。在国内,包茨、顿铁军等提出的孔、洞、缝分类系统具有代表性。本文对碳酸盐岩孔隙分类方法研究进行了综述。

羊毛分梳下脚料生产带子纱的工艺

主要介绍了利用梳绒厂梳落废弃的山羊毛、驼毛、牦牛毛等粗毛、腔毛,配合其他原料,在现有纺纱流程上,增加花式纺纱设备,优选工艺参数,生产带子纱。根据落毛的特点,在羊毛处理工艺上做了相应的调整,如洗毛前对粗毛、腔毛除杂,梳理时选用合适的针布,并采用大速比、大隔距。生产带子纱时,对花式纱线喂入装置进行改造,使粗纱能够准确落入带子中,保证纺纱顺利进行,带子纱主要用于生产装饰织物如壁毯、挂毯等。

LTCC单膜层内置腔制造技术

LTCC单膜层内置腔在电容式传感器、微流系统等领域有重要应用,是3D-LTCC在微系统领域应用的典型结构类型。首先论述了目前实现内置腔制造的主流技术——牺牲层技术,并结合实验点明了该技术的关键难点。之后,提出了一种LTCC内置腔制造的新方法,并结合实验验证了该方法的可行性。新方法比牺牲层方法简便,更适合于高平整度腔膜层内置腔结构制造。

高功率转换效率905 nm垂直腔面发射激光器的设计与制备

通过对影响垂直腔面发射激光器(vertical cavity surface emitting laser, VCSEL)的功率转换效率的因素进行理论分析,得出斜率效率是影响功率转换效率的主要因素的结论.为获得高功率转换效率,通过对有源区量子阱、P型和N型分布布拉格反射镜(DBR)等进行优化,设计出了905 nm VCSEL的外延结构并进行了高质量外延生长.成功制备出了不同氧化孔径的905 nm VCSEL器件,获得的最大斜率效率为1.12 W/A,最大转换效率为44.8%.此外,探究了氧化孔径对VCSEL的远场和光谱特性的影响.这种具有高功率转换效率的905 nm VCSEL器件为激光雷达的小型化、低成本化提供了良好的基础数据.

多腔体多边形钢管柱分片加工制作技术

昆明春之眼商业中心主塔楼角部有6根多腔体多边形巨型钢管柱,将钢管柱分片加工制作并应用BIM技术,解决了巨型钢管柱截面大、重量重、运输及安装困难等问题.采用厂内卧拼技术减少了分片加工误差和安装误差,提高了施工效率,保证了安装精度.

MEMS封装V形腔阵列的研究与制备

MEMS器件封装时,为了给具有活动装置的MEMS器件提供足够的空间,需要在封装的帽层上刻蚀出V形腔结构。本文利用V形槽工艺,制作出适合于硅片上大面积MEMS芯片封装用V形腔阵列。SEM照片表明,所做V形腔阵列结构整齐,图形清晰。

一种光子晶体开放腔的特性研究

为了研究光子晶体开放腔特性,采用平面波展开法和时域有限差分法对顶角为30°楔角的光子晶体和空气槽交替组成的新型光子晶体开放腔进行了研究。研究发现,这种结构的光子晶体开放腔在两个归一化频率范围(0.3006～0.35,0.6755～0.6851)内具有负折射特性,并且在负折射频率范围内可形成一个零光程的闭合回路;光子晶体与空气槽的分界面上有高的透射率,能够在某个波长产生共振。结果表明,可以利用共振波长随着折射率的变化而变化的光子晶体开放腔实现折射率的高灵敏度测量。

High-sensitivity refractive index sensors based on Fano resonance in a metal-insulator-metal based arc-shaped resonator coupled with a rectangular stub

A metal-insulator-metal(MIM)-based arc-shaped resonator coupled with a rectangular stub(MARS) structure is proposed. This structure can generate two tunable Fano resonances originating from two different mechanisms. The structure has the advantage of being sensitive to the refractive index, and this feature makes it favorable for application in various microsensors. The relationship between the structural parameters and Fano resonance is researched using the finite element method(FEM) based on the software COMSOL Multiphysics 5.4. The simulation reveals that the sensitivity reaches1900 nm/refractive index unit(RIU), and the figure of merit(FOM) is 23.75.