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1.
刘卫丽 《上海计量测试》1999,26(4):34-36,55
采用光学干涉仪准确地测量长度是非常容易的。然而,如果没有一个用来计算干涉条纹的运动装置,单频干涉仪的测量范围就被限制于小于半波长。为了解决这个问题,已经研究出一种频率扫描方法。它的相位分辨率不是太高,不过于涉条纹级次的整数部分可以确定下来。我们建议使用一种能够准确地测量长度的方法,那就是将高分辨率的相位测量技术和频率扫描技术相结合。这里使用一台频率扫描外差式干涉仪对这个方法进行研究。使用宽带频率扫描方法,结合外差相位测量,我们可以得到优于四分之一波长的高分辨率。这就意味着,我们测量绝对长度的精度达到纳米级,因为通过频率扫描可以确定条纹干涉级次的整数部分。测量距离在4mm时精度达到3mm。  相似文献   

2.
《照相机》2012,(5):85-85
近日.东芝发布Exceria系列高速SDHC及SDXC卡,支持UHS-1标准,最高读取速度达到95MB/S,最高写入速度90MB/s。此外该系列产品还将提供读写速度为95/60MB/s及95/30MB/s的版本。  相似文献   

3.
白金海  胡栋  贡昊  王宇 《计测技术》2020,40(6):26-30
研制了一种用于原子干涉仪的外差式光学锁相环系统,实现了两台外腔半导体激光器频率和相位的同步,锁相后的激光拍频线宽低于1 Hz,10 MHz积分带宽内的残余相位噪音为0.002 rad2,频偏1~100 kHz范围内的相位噪音达到-100 dBc/Hz。研究了闭环相位噪音对原子干涉仪的影响,当自由演化时间为200 ms、拉曼π脉冲时间为30 μs、单次循环时间为1 s时,锁相后相位噪音对重力测量灵敏度的贡献为10μGal?Hz-1/2  相似文献   

4.
微片激光自混合干涉仪原理上与迈克尔逊干涉仪不同。主要差别是:激光自混合干涉仪的光束照射在被测物上并被反射回激光器被激光器内放大介质放大。作者课题组研究的的激光自混合干涉仪的测量速度达到了1 m/s以上,10 m空程的环境误差小到了40 nm。它具有全固态、可测"黑"目标的位移等性能,又达到了传统激光干涉仪的技术指标。如果第一代光学干涉仪是以光谱灯做光源,第二代光学干涉仪是以He Ne气体激光器做光源的话,固体激光自混合干涉仪因其激光"自混合"原理可看成是第三代激光干涉仪。  相似文献   

5.
微片激光自混合干涉仪原理上与迈克尔荪干涉仪不同。主要差别是:激光自混合干涉仪的光束照射在被测物上并被反射回激光器被激光器内放大介质放大。作者课题组研究的的激光自混合干涉仪的测量速度达到了1 m/s以上,10 m空程的环境误差小到了40 nm。它具有全固态,可测“黑”目标的位移等性能,又达到了传统激光干涉仪的技术指标。如果第一代光学干涉仪是以光谱灯做光源,第二代光学干涉仪是以HeNe气体激光器做光源的话,固体激光自混合干涉仪因其激光“自混合”原理可看成是第三代激光干涉仪。  相似文献   

6.
研制了一台用于0.5~100 mm量块测量的新型移相量块干涉仪,分别以波长为633 nm和543 nm的两台稳频激光器作为测量光源,通过一根单模光纤引入到干涉仪内。高精密移相器实现5步移相干涉测量,CCD相机采集干涉条纹并计算干涉条纹小数,被测量块长度采用多波长的小数重合法计算。移相量块干涉仪的测量不确定度达到U=0.015μm+0.07×10~(-6)L(L为量块长度,mm)。  相似文献   

7.
利用一维光子晶体波导慢光和正交信号处理技术,提出了一种具有高灵敏度和宽测量范围的慢光马赫-曾德干涉仪光频率检测系统。理论分析表明,正交信号处理技术可以消除M-Z干涉仪测量灵敏度与测量范围间的矛盾。然后,通过有限时域差分法对一维光子晶体波导结构进行分析和优化,在750GHz光频率范围内,获得了群折射率为10.7的慢光,使M-Z干涉仪的光频率测量灵敏度提高了10倍。最后,利用4×4耦合器搭建了实验系统,将测量范围提高到原干涉仪的6倍。  相似文献   

8.
水中脉冲电晕放电测试系统   总被引:1,自引:0,他引:1  
建立了一套水中电晕放电测试系统.由高速摄影系统、电参数测量系统和压力测量系统组成.高速摄影系统由GSJ转镜式高速摄影仪和德国产Pentazet35型摄影仪等组成,最高拍摄频率分别为250万幅/s和4万幅/s.电参数测量系统由高压表、电阻分压器、同轴分流器和Tektronix THS730A示波器组成.详细分析了整个系统的敏感设备、干扰源及其传播途径,并提出了相应的控制措施.压力测试系统主要有压电式传感器等组成.  相似文献   

9.
本文通过实验验证了一种新型的测量液体流动的流速传感器。液体流动的力作用在小圆盘上,导致悬臂梁的扭曲变形。将布拉格光纤光栅植于悬臂梁上。通过检测布拉格光纤光栅波长漂移,就可以得到液体流速。实验结果显示了这种传感器的可行性。实验实现的测量范围为0--120cm/s,测量精度最高可达到5cm/s。同时,本文提出了通过改变传感器的材料可以扩大测量范围。  相似文献   

10.
《照相机》2005,(7):31
该机具有510万有效像素CCD影像传感器,采用3倍变焦(相当于35mm相机的35~105mm)尼克尔ED镜头,4倍数码变焦。2.5英寸11万像素LCD液晶显示屏。开机时间1s,最高连拍速度约1.8张/秒。  相似文献   

11.
Ohta T  Nishizawa N  Ozawa T  Itoh K 《Applied optics》2008,47(13):2503-2509
A practical all-fiber three-dimensional measurement system is demonstrated with an incoherent interferometer at the eye-safe wavelength of 1.55 mum. The sensitivity and axial resolution are as high as 102 dB and 1.4 mum from a few meters' distance, respectively. A rotating scanner is developed for axial scanning, and a wide longitudinal scanning range of 54 mm is demonstrated. The high resolution images of a few samples are clearly obtained at the speed of 52 points/s. Moreover, the resolution, sensitivity, speed, and angle dependence are discussed for measurement of a 100 yen Japanese coin.  相似文献   

12.
为解决法布里?珀罗(Fabry?Perot, F?P)干涉仪锁频方法响应速度、抗干扰能力、长期稳定性方面存在不足的问题,提出了F?P干涉仪差分锁频方案,将存在频差的双频激光耦合入F?P谐振腔,当激光频差足够小时,两光强信号曲线存在交叉,以两光强信号的差值作为被控量,在交叉点附近构建单调过零函数,作为闭环控制系统的反馈量,实现动态差分锁频控制。基于该方案,搭建了一套F?P干涉仪微位移测量装置并开展实验验证,结果表明该装置能够实现0 ~ 300 nm范围内的微位移测量,位移测量分辨力达到23 pm,验证了F?P干涉仪差分锁频方案的有效性,为推动微位移测量领域的发展提供了重要借鉴。  相似文献   

13.
Pierce RM  Roark SE 《Applied optics》2012,51(12):1853-1864
Wind speed can be measured remotely, with varying degrees of success, using interferometry of Doppler-shifted optical spectra. Under favorable conditions, active systems using laser pulse backscatter are capable of high resolution; passive systems, which measure Doppler shifts of atmospheric emission lines in the mesosphere, have also been shown. Two-beam interferometry of Doppler-shifted absorption lines has not been previously investigated; we describe such an effort here. Even in a well-defined environment, measuring absorption line Doppler shifts requires overcoming several technical hurdles in order to obtain sensitivity to wind speeds on the order of 10 m/s. These hurdles include precise knowledge of the shape of the absorption line, tight, stable filtering, and understanding precisely how an interferometer phase should respond to a change in the absorption profile. We discuss the instrument design, a Michelson interferometer and Fabry-Perot filter, and include an analysis of how to choose the optimal optical path difference of the two beams for a given spectrum and filter. We discuss two beam interferometric measurements of emission line and absorption line Doppler shifts, and include an illustration of the effects of filtering on LIDAR Doppler interferometry. Finally, we discuss the construction and implementation of a Michelson interferometer used to measure Doppler shifts of oxygen absorption lines and present results obtained with 5 m/s wind speed measurement precision. Although the theoretical shot noise limited Doppler wind speed measurement of the system described can be less than 1 m/s, the instrument's resolution limit is dominated by residual filter instability. Application of absorption line interferometry to determine atmospheric wind speeds remains problematic.  相似文献   

14.
针对自动络筒机落纱小车自主开发需求,设计出一种基于机器视觉的条码尺精确测量技术检测落纱小车在轨道上的位置。该测量方法以条码尺为基准,条码尺由刻度尺和条形码组成。实验中首先在相机初始位置对相机与条码尺进行标定,相机移动过程中实时获取当前对应条码尺图像,计算出当前条码尺坐标,从而计算出相机相对于条码尺的位移。结果表明:该测量方法无累积误差,实现了小车在行走过程中位置的实时监测。相机帧频为30 Hz、物距为15 cm时,输出图像分辨率为640×480像素;小车运行速度小于2 cm/s时,条码尺坐标测量误差小于1 mm;速度在2~6 cm/s之间时,条码尺坐标测量误差为1~2 mm;速度为6~10 cm/s时,条码尺坐标测量误差为2~3.5 mm。该方法能够满足落纱小车低速运行情况下定位精度的要求。  相似文献   

15.
Yokota M  Asaka A  Yoshino T 《Applied optics》2001,40(28):5023-5027
A closed-loop phase-shifting Fizeau-type interferometer was constructed that uses direct frequency modulation of a laser diode. The interferometer is servo controlled entirely in the phase domain, where optical phases are detected by two-frequency optical heterodyning. A detailed study of stabilization of the interferometer under feedback control was conducted both experimentally and theoretically. The interferometer showed good stability against vibration up to 200 Hz. The stabilization factors obtained experimentally are in good agreement with the theoretical calculations. The phase-shifting experiment was accomplished with high precision as well as with high stability against external disturbances. The profile measurement of a mirror surface was made with a phase-shifting analysis algorithm, and good measurement reproducibility of lambda/60 in the root-mean-square value was obtained for ten measurements within a period of 20 min.  相似文献   

16.
郎非 《光电工程》2005,32(4):5-8,12
对高帧频电视测量的炸点目标飞行指标进行了分析,推导出测角误差、作用距离、飞行时间与飞行高度等飞行指标的计算公式,在此基础上对不同速度的相机和不同速度的运动目标的测角误差进行了对比研究。结果表明,采用高帧频电视测量对减小测角误差作用明显;同时,根据作用距离与相机拍摄速度的制约关系,进一步得出作用距离与拍摄速度的关系式。当相机工作在200fps,炸点飞行速度小于50m/s,爆炸当量200g TNT,利用对比分析结果和推导出的关系式,计算出测角误差小于50″,最大作用距离3km。经靶场实测,计算结果与实际飞行指标基本吻合。  相似文献   

17.
许海  赵淳生 《振动与冲击》2007,26(6):100-102
研制了一种新型直线超声电机,首先对其驱动机理进行探讨,设计电机的具体结构,其次对定子进行频率响应实验,模态实验,实验显示电机可有效激励出所需振型,正反向运动灵活,电机的工作频率42550Hz;最大无负载速度可达76mm/s,最大输出推力2N。  相似文献   

18.
A method for simultaneous measurement of geometric thickness and refractive index of an optical wafer is presented. By using a fiber optic Mach–Zehnder interferometer (MZI) with a free space, the transmission spectrum of a MZI for the optical wafer at different incidence angle is interrogated, and the geometric thickness and the refractive index of the optical wafer are measured simultaneously. With the transmission spectrum, we can obtain a clear interferogram with a high visibility no matter how small the measurement range of the refractive index. Therefore the proposed technique possesses a broad measurement range and low cost. The experimental results show that the maximum errors of the geometric thickness and the refractive index are only 0.007?mm and 0.008, respectively, and that a broad measurement from 1.316 to 3.503 can be achieved.  相似文献   

19.
O'Hora M  Bowe B  Toal V 《Applied optics》2006,45(22):5607-5613
Frequency changes induced by bias or temperature modulation of injection diode lasers can provide an economical and effective method of applying phase-stepping interferometry to optical metrology. However, the intrinsic frequency instability of these devices limits their use in gauge block interferometry where precise and repeatable phase steps must be maintained simultaneously on two discontinuous surfaces and over relatively long path lengths. We demonstrate a method using a visible injection diode laser, the frequency of which is locked by using a Fabry-Perot interferometer. Small changes to the length of the Fabry-Perot interferometer shift the frequency of the laser producing proportional and repeatable phase steps to the gauge block interferogram. This method has been successfully implemented with a Fizeau-type gauge block interferometer with a phase measurement resolution of 0.005 lambda. The phase data are then processed to map the surface form of gauge blocks up to 100 mm in length and to objectively assess surface shape parameters.  相似文献   

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