误差因素对微角度传感器性能的影响

叙述了一种基于光学内反射的非接触式角度传感器的设计原理和特点,分析了该角度传感器的关键器件临界角棱镜的参数设计,着重讨论了临界角棱镜的加工误差对系统特性的影响。通过计算和实验发现,通过控制临界角棱镜的入射中心角误差不大于20",两平行反射表面的一致不平行度误差小于30",以及反射表面的平面度优于λ/4可以使该传感器在3 测量范围内获得0.02"的分辨率。     

五棱镜激光偏振器

利用五棱镜和电介质多层膜,设计出一种消光比,光损伤阈值,利用效率高的新型棱镜偏振器。偏振分离是通过对电介质多层膜的斜入射进行的。虽然入射角小,为22.5°,但是,通过用高折射率玻璃和五棱镜内的两次反射,不仅透射光(P波)而且用反     

基于CCD技术的玻璃测厚系统

针对传统厚度测量方法的弊端,研究了利用半导体激光和线阵电荷耦合元件(CCD)组成的在600 ℃高温条件下的一套非接触式、在线玻璃厚度检测系统.利用几何光学中光的反射和折射原理对玻璃进行非接触测量,选用TCD1501C线阵CCD作为图像传感器,设计了CCD视频信号处理电路.玻璃厚度测量的精度能达到0.01 mm(测量范围在2～20 mm).     

红外扫描棱镜镀膜的光学特性

扫描棱镜是热象仪中的重要部件之一。根据热象仪使用的不同要求设计的扫描棱镜可分为反射式和透射式两大类。为了配合热象仪试制的需要,我们开展了Ge棱镜镀多层增透膜、玻璃棱镜和铝合金棱镜镀反射膜的研制工作。本文将分别把这几种棱镜镀膜后的光学特性作一介绍。     

用Matlab验证液晶参数综合测试系统中反射棱镜的偏振自补偿特性

设计了一种利用K9玻璃材料制成的空间转向反射棱镜,其具有相对旋转90°的两个反射面,光束经两个反射面反射时入射角相等,光束反射时产生的相位差大小相等,但方向相反,可以互相抵消,确保了反射光和入射光偏振特性一致,实现偏振特性的自补偿。通过测试实验并经Matlab拟合,验证了该空间转向反射棱镜具有很好的偏振自补偿特性。     

表面等离子体共振传感器自适应测量光路

提出了一种用于表面等离子体共振（SPR）传感器的双棱镜自适应光路设计。采用2个完全相同的等腰直角三棱镜,1个作为Kretschmann棱镜结构传感器的元件,另1个作为光路的调整元件。当入射光固定,对双棱镜结构进行角度扫描时,出射光与入射光始终平行,只随着出射点的改变发生小的平移,利用凸透镜进行会聚,可以实现扫描过程中光探测器的固定不动。它避免了传统角扫描SPR传感器需要θ／2θ转角仪来对棱镜和光探测器分别进行θ和2θ角旋转的复杂结构,减少了运动部件,使仪器装置结构简单、紧凑、操作简便。     

检验平行度和棱镜角的干涉方法

给出了快而方便地检验光学元件的例子：玻璃块的平行度、波洛棱镜的90°角误褰和棱镜的尖塔差和直角棱镜45°角的误差。用氦-氖激光源，而以待测元件充当干涉仪。     

光干涉方法在角度偏差测量中的应用

介绍了应用光学干涉原理测量棱镜光学平行差的方法.棱镜可等效展开为玻璃平板,其入射面与出射面的光程差恒定,通过波长调谐方法,改变等效玻璃平板之间的位相差,从而用移相干涉术测量了光学棱镜的光学平行差.介绍了一种立方体玻璃90°偏差测量的新方法,斐索干涉仪的测试光束以45°入射到立方体玻璃内,入射波面经立方体90°二面角自准直反射,与干涉仪参考波面相干形成干涉图.分析了干涉波面与立方体玻璃二面角误差之间的关系,并通过移相式干涉仪给出了实测结果.     

二维加速度激光传感器的设计

以角锥棱镜作为惯性元件,利用光学干涉原理,可以实现对运动物体的二维加速度测量。本文给出了二维加速度激光传感器的设计理论和测量原理。     

角度误差影响运动角锥棱镜反射特性的理论分析

角度误差对运动角锥棱镜反射特性有何影响,国内未见报导。本文根据矩阵光学理论证明了,角度制造误差将引起运动角锥棱镜反射光束空间方位的随机改变,但其改变属于高阶小量。这个结论对于将角锥棱镜作为He-Ne激光频率分裂位移传感器动镜使用,具有指导意义。     

Fast-response silicon flow sensor with an on-chip fluid temperature sensing element

A new silicon flow sensor with a robust thermal isolation structure has been developed. The thermal isolation structure is mainly made of a 20-µm-thick oxidized porous silicon membrane. This thermal isolation structure makes it possible for the sensor to have a fast-response characteristic and an on-chip fluid temperature sensing element design. The sensor can be used in liquid flow as well as gas flow. Its operation is based on heat transfer from the heated sensor to a moving fluid. It has two platinum thin-film resistors, a heating element, and a fluid temperature sensing element on the chip. The sensing element is thermally isolated from the heating element. The external circuit of the sensor maintains a constant temperature difference between the heating element and the fluid. The sensor chip characteristics were evaluated theoretically by heat transfer analysis during the chip design. Measurements were made for oil flow velocity of 0-30 cm/s and air flow velocity of 0-14 m/s. Response time was below 100 ms, and a compensated output for fluid temperature change was obtained.     

Transmission-type SPR sensor based on coupling of surface plasmons to radiation modes using a dielectric grating

A transmission-type surface plasmon resonance (SPR) sensor is presented. In the transmission-type SPR structure, surface plasmon waves are outcoupled to radia-tion modes by the use of dielectric grating on a thin-film layer of Ag. Compared with the traditional reflection-type SPR sensor, the new method provides larger detectable range, which might be useful to investigate thick targets such as in cell analysis. Theoretical simulations show that the structures provide high transmission efficiency for surface plasmon resonance and the devices present extre-mely linear sensing characteristics. Furthermore, it is found that the transmission efficiency and the refractive index detection sensitivity of the SPR sensor can be improved by the use of a lower refractive index glass prism.     

Fiber ring laser with flint glass fiber and its sensor applications

A new fiber ring laser has been proposed which is composed of a laser diode amplifier, a flint glass fiber as a sensing element, and a Faraday cell as a bias element, and applied to a frequency-domain sensor in which nonreciprocal effects such as current or rotation can be measured from a frequency change in the beat signal. A sign of current or rotation direction can be determined and a lock-in phenomenon is avoided owing to the bias element     

Stabilized extrinsic fiber-optic Fizeau sensor for surface acousticwave detection

A surface acoustic wave sensor based on an in-line extrinsic Fizeau interferometer is described. A single-mode fiber, used as the input/output fiber, and a multimode fiber, used solely as a reflector, form an air-gap that acts as a low-finesse Fabry-Perot or Fizeau cavity. The Fresnel reference reflection from the glass/air interface at the front of the air-gap interferes with the sensing reflection from the air/glass interface at the far end of the air-gap. Strains in the thin-walled silica tube housing the two fibers change the length of the air-gap, thereby altering the phase difference between the reference and sensing reflections. A theoretical analysis of the interaction between the strain induced by elastic stress wave fields and the fiber sensor housing is presented     

Monolithic pressure-flow sensor

A new silicon-based monolithic pressure-flow sensor has been developed. Its operation is based on the piezoresistive effect for pressure sensing and heat transfer for flow sensing. The sensor chip has a thermal isolation structure that is made of an oxidized porous silicon membrane. This structure thermally isolates the heating element located on the membrane from the rim of the chip. The sensor, in which the chip was mounted on a wall of an acrylate plastic pipe, was designed for biomedical applications. Measurements were made at pressures of 0-300 mmHg, water flow rates of 0-7 1/min, and fluid temperatures of 25-45°C. The temperature difference between the heating element and the fluid temperature sensing element was kept at 5°C. The sensor showed a pressure sensitivity of 1.32 µV/mmHg for 1-mA current supplied, a nonlinearity of 0.5 %F.S. for pressure sensing, an accuracy of ±10 %F.S. for flow sensing, and 90-percent response time of below 100 ms for flow sensing. The sensor was applied to the simultaneous measurements of pressure and flow rate in pulsedflow experimental systems.     

Resistive humidity sensor based on vanadium complex films

A resistive-type relative humidity （RH） sensor based on vanadium complex （VO2（3-f[）） film is reported in this study. Gold electrodes were deposited on the glass substrates in a co-planar structure. A thin film of vanadium complex was coated as a humidity-sensing material on the top of the pre-patterned electrodes. The humidity-sensing principle of the sensor was based on the conductivity change of coated sensing element upon adsorption/desorption of water vapor. The resistance of the humidity sensor measured at 1 kHz decreased linearly with increasing the humidity in the range of 35%-70% RH. The overall resistance of the sensor decreases 11 times. An equivalent circuit for the VO2（3-fl） based resistive-type humidity sensor was developed. The properties of the sensor studied in this work make it beneficial for use in the instruments for environmental monitoring of humidity.     

A capacitive fingerprint sensor chip using low-temperature poly-Si TFTs on a glass substrate and a novel and unique sensing method

We have developed a capacitive fingerprint sensor chip using low-temperature poly-Si thin film transistors (TFTs). We have obtained good fingerprint images which have sufficient contrast for fingerprint certification. The sensor chip comprises sensor circuits, drive circuits, and a signal processing circuit. The new sensor cell employs only one transistor and one sensor plate within one cell. There is no leakage current to other cells by using a new and unique sensing method. The output of this sensor chip is an analog wave and the designed maximum output level is almost equal to the TFT's threshold voltage, which is 2-3 V for low-temperature poly-Si TFTs. We used a glass substrate and only two metal layers to lower the cost. The size of the trial chip is 30 mm/spl times/20 mm/spl times/1.2 mm and the sensor area is 19.2 mm/spl times/15 mm. The size of the prototype cell is now 60 /spl mu/m/spl times/60 /spl mu/m at 423 dpi, but it will be easy to increase the resolution up to more than 500 dpi. The drive frequency is now 500 kHz and the power consumption is 1.2 mW with a 5-V supply voltage. This new fingerprint sensor is most suitable for mobile use because the sensor chip is low cost and in a thin package with low power consumption.     

填充混合液体的光子晶体光纤温度传感研究

为获得高灵敏度光子晶体光纤温度传感,在实心光子晶体光纤（PCF）空气孔中填充氯仿和酒精等高折射率热敏液体的混合物。理论上采用有限元法分析了温度对光纤模场面积和限制损耗的影响。通过调节液体的混合比,使损耗对温度的灵敏度达到最大值,实现了高灵敏度PCF温度传感。实验表明,填充液体的长为4mm的PCF温度传感器,灵敏度经检测...     

一种新颖温敏材料的光纤温度多路测量系统

本文讨论的是一种新颖温敏材料的实用型光纤温度传感器,这种传感器采用了新颖的半导体着色玻璃材料,全玻璃传感探头,在整体设计上采用了双波长误差校正系统,光源及光电检测器恒温系统,有效地减少了漂移,并且由于使用星形光纤耦合器及单片微机系统而提高了整机的性能价格比。     

MEMS热式风速风向传感器输出性能优化研究

环境测温二极管在工作时受传感器芯片热场影响,常引发MEMS热式风速风向传感器加热电压-风速曲线异常。将其更换为外置测温二极管,并调整其与传感器芯片距离,成功解决了输出曲线异常现象。并在此基础上,优化芯片及外置测温二极管的封装方案,消除了热场的相互干扰和不必要的热损耗,同时保证了外置测温二极管与空气的良好接触。风场测试结果表明,传感器的加热电压-风速曲线变得平滑,且重复性好,风速和风向的测量误差分别在±4%和±4°以内,系统的上电稳定时间大幅缩短至15 s左右。