This PDF file contains the front matter associated with SPIE Proceedings Volume 8916, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

Advances in emerging technology of microelectromechanical systems (MEMS) are one of the most challenging tasks in today's experimental mechanics. More specifically, development of these miniature devices requires sophisticated design, analysis, fabrication, testing, and characterization tools that have multiphysics and multiscale capabilities, especially as MEMS are being developed for use at harsh conditions. In harsh-environment and high-performance guidance applications inertial sensors must be sensitive to low rates of rotation yet survive the high blast loads associated with the initial launch. In this multi-year study a set of tuning fork gyroscopes (TFGs) were subjected to a series of increasing g-loads (culminating at approximately 60,000 g’s) with measurements of shape made after each test. High-g-testing was conducted within the large test chamber using a custom fabricated mini powder gun. A custom set of test sample packages were hermetically sealed with glass lids to allow optical inspection of components while preserving the operating (vacuum) environment. Optical and interferometric measurements have been made prior to and after each shock g-loading. The shape of the TFG test articles was measured using optoelectronic laser interferometric microscope (OELIM) methodology. Line traces were extracted from pertinent structures to clearly examine changes in the TFG. Failure of the die was observed in the form of fractures below the chip surface as well as fractures in the glass lid sealing the package.

Modern manufacturing is based on internationally accepted procedures and standards for production control which in turn require a system which guarantees globally comparable measurements, traceable to the international system of units, the SI. In the field of nanotechnology, however, the requirements for traceable characterization of functional structures and nanomaterials results in additional challenges due to the complex interaction of the nanoobjects of interest with the different kinds of high resolution microscopic (e.g. SEM, AFM) or integral (e.g. diffraction) measurement probes used for their characterization. Appropriate models for the description of the interaction between sample features and measurement probe have to be developed and applied in order to traceably determine dimensional parameters of the nanoobjects and to compare the results from different measurement methods. In this contribution examples for traceable characterization of functional parameters of manufactured nanostructures as well as nanoparticles will be given based on recent activities of the PTB, the national metrology institute of Germany with a focus on the support of nanomanufacturing processes.

As the sensitivity of the fractional differential algorithm for detail image texture extraction and the difficulty of the best fractional differential order fingding, a novel adaptive fractional differential method is proposed, which can adaptively select the fractional differential order according to the mask window size, definition of fractional differential equations, the composite sub-band gradient vector (CSGV) obtained from the sub-images through a wavelet decomposition of a texture image, and human visual property. The fractional differential operator mask based on G-L formula is designed and realized by employing the adaptive order. The evaluation parameters of image texture feature extraction such as the image information entropy and multi-scale structural similarity (MS-SSIM) are used for quantitative analysis of the extraction method in experiment The experiment results show that for grey texture image this method is able to extract image texture and edge details completely, which approximate the results of optimal fractional differential order and more satisfies human visual sense. It is an effective approach to extract fine texture features of images.

A tester for measuring face gears’ transmission error was developed based on single-flank rolling principle. The mechanical host was of hybrid configuration of the vertical and horizontal structures. The tester is mainly constituted by base, precision spindle, grating measurement system and control unit. The structure of precision spindles was designed, and rotation accuracy of the spindleswas improved. The key techniques, such as clamping, positioning and adjustment of the gears were researched. In order to collect the data of transmission error, high-frequency clock pulse subdivision count method with higher measurement resolution was proposed. The developed tester can inspect the following errors, such as transmission error of the pair, tangential composite deviation for the measured face gear, pitch deviation, eccentricity error, and so on. The results of measurement can be analyzed by the tester; The tester can meet face gear quality testing requirements for accuracy of grade 5.

One critical challenge for high-volume nanomanufacturing requires the on-line monitoring and measurement of the nanostructures manufactured. Computational metrology is expected to provide a novel means for fast, low-cost, nondestructive, and accurate measurement in high-volume manufacturing. Computational metrology refers to a measurement method where a complicated measurement process is modeled as a forward problem and some measured data are obtained by a specific instrument under a certain measurement configuration, and then the measurands are precisely and accurately reconstructed by solving the corresponding inverse problem. Thus computational metrology is essentially a model-based metrology and a typical process to solve an inverse problem. The key issues in computational metrology, such as the measurability, the measurement error analysis and precision estimation, the measurement configuration optimization, the fast and accurate forward modeling, and the fast and robust measurand reconstruction, and their generalized solution methods are explored in this paper, with an emphasis on the significance and necessity to apply modern mathematical theories and tools in solving the related problems. Some case studies carried out in my research group are presented to demonstrate the capability of computational metrology.

An experiment of absolute distance measurement by spectrally resolved interferometry has been executed. A Ti:Sapphire femtosecond laser without stable frequency and stable phase was used as an optical source of the measurement system. It greatly simplifies the complexity of the measurement system. A Fabry-Perot Etalon made by ourselves was employed as an optical filter to pick up frequency modes from the broad bandwidth spectrum of femtosecond laser pulse. To achieve the absolute distance, a linear array CCD detector was used to get the interferometric phase information for the calculation of distance. The measurement experiment was carried out in the non-ambiguity range and ranging precision of less than 5 μm was achieved. The result indicates that it’s feasible to measure the absolute distance by spectrally resolved interferometry with a simple femtosecond laser.

A nanopipette ball probe has been introduced for the dimensional measurement of the micrometer-scale structures. A hollow glass nanopipette, which is fabricated by thermal pulling process, is used as the shaft of the probe for the detection of the contact. Since the stiffness of the glass nanopipette is lower than that of metal shaft which is similar size of the glass nanopipette, the contact force between the probe and the sample will be able to reduce in comparison with the probe of the metal shaft. The edge of the nanopipette is filled with the thermosetting resin, and a micro glass sphere with 9 mm diameter is fixed on the edge of the nanopipette probe by the thermosetting resin. By attaching the micro sphere at the edge of the nanopipette, the edge of the probe will be possible to maintain a uniform shape in all directions. With regard to the detection of the contact, the method of the shear-force detection has been employed because of its high-sensitivity and nanometer-scale resolution. The resolution and the sensitivity of the nanopipette probe are evaluated, and then surface profile measurement of the microstructure is demonstrated.

Any linear stage has inherent geometrical errors due to manufacturing errors. The induced Abbé errors have to be compensated for the accuracy of positioning. In addition, although the commercial laser interferometer is capable for the displacement sensing to nanometer resolution, it is, however, bulky in size, expensive in cost and not able to correct the Abbé errors caused by angular errors of the moving stage. In order to minimize and simplify the interferometer as a practically useful sensor for nanopositiong stages in industrial use, this paper presents a newly developed miniature multi-degree-of-freedom measurement system (MDFMS), which is constructed by a wavelength corrected Michelson interferometer and a dual-axis autocollimator. The wavelength correction of the miniature laser interferometer is calibrated by SIOS and controlling the temperature within ±2 ºC, the wavelength stability is less than 10^-6. After calibration, the accuracy of the miniature laser interferometer can reach 32 nm for the travel of 20 mm long. The collimator has accuracy of ±0.3 arc-sec within the range of ±30 arc-sec. This MDFMS has been integrated into the developed Micro-CMM as a feedback sensor in each axis of the coplanar stage.

Ball bearing is an important type of bearings. The radial acceleration of ball bearings has been measured for monitoring and diagnosis. Feature extraction is used to extract essential features from the experimental data. Three features, including peak amplitude of the frequency domain, percent power, and peak RMS, have been extracted from the radial acceleration of ball bearings. Then Sequential Forward Search Algorithm (SFS） was utilized for feature selection in order to effectively obtain the best vibration features. Adaptive Neuro Fuzzy Inference Systems (ANFIS) have been used. The selected features were the inputs to the neuro-fuzzy system. Whether there is a defect or not and what types of defects were the outputs of this system. Although there is no analytical relationship between the input and the output of the neuro-fuzzy system, this system still can establish the input/output relationship. In other words, this approach can most accurately, most quickly, and most reliably determine whether there is a defect or not and what types of defects, which is very important for preventive monitoring, diagnosis, and maintenance of ball bearings.

We present an overview of approaches to the design of nanometrology measuring setups with a focus on methodology of nanometrology interferometric techniques and associated problems. The design and development of a positioning system with interferometric multiaxis monitoring and control involved for scanning probe microscopy techniques (primarily atomic force microscopy, AFM) for detection of the sample profile is presented. Coordinate position sensing allows upgrading the imaging microscope techniques up to quantified measuring. Especially imaging techniques in the microand nanoworld overcoming the barrier of resolution given by the wavelength of visible light are a suitable basis for design of measuring systems with the best resolution possible. The system is being developed in cooperation with the Czech metrology institute and it is intended to operate as a national nanometrology standard combining local probe microscopy techniques and sample position control with traceability to the primary standard of length.

High accuracy full field three dimensional (3D) deformation measurements have always been an essential problem for the manufacturing, instrument, and aerospace industry. 3D deformations, which can be translated further into 3D strain and stress, are the key parameter for design, manufacturing and quality control. Due to the fast development of the manufacturing industry, especially in the automobile and airspace industry, rapid design and optimization concepts have already widely accepted. These concepts all require the support of rapid, high sensitive and accuracy 3D deformation measurement. Advanced optical methods are gaining widely acceptance for deformation and stain measurement by industry due to the advantages of non-contact, full-field and high measurement sensitivity. Of these methods, Electronic Speckle Pattern Interferometry (ESPI) is the most sensitive and accurate method for 3D deformation measurement in micro and sub micro-level. ESPI measures deformation by evaluating the phase difference of two recorded speckle interferograms under different loading conditions. Combined with a phase shift technique, ESPI systems can measure the 3D deformation with dozens of nanometer level sensitivity. Cataloged by phase calculation methods, ESPI systems can be divided into temporal phase shift ESPI systems and spatial phase shift ESPI system. This article provides a review and a comparison of temporal and spatial phase shift speckle pattern interferometry for 3D deformation measurement. After an overview of the fundamentals of ESPI theory, temporal phase-shift and spatial phase-shift techniques, 3D deformation measurements by the temporal phase-shift ESPI which is suited well for static measurement and by the spatial phase-shift ESPI which is particularly useful for dynamic measurement will be discussed in detail. Basic theory, brief derivation and different optical layouts for the two systems will be presented. The potentials and limitations of the both ESPI systems will be demonstrated by examples of precise and simultaneous measurement of 3D deformations under either static or dynamic loadings.

The spherical joint clearance is a key error factor, which influenced and restricted the application of parallel mechanism in high precision field. This paper discusses the regularity of the spherical joint clearance in the parallel mechanism and its influence on the accuracy of the parallel mechanism in both theoretical and experimental aspects. A spherical joint clearance measuring instrument is introduced and used to measure the joint clearance. And the relationship between the clearance and its work pose is revealed. Based on the theoretical and experimental analysis, it is concluded that the clearance of the spherical joint is near-linear proportional to the applied load as well as the clearances in different poses obey the Rayleigh distribution approximately under the same load.

In order to improve the performances of dynamic atomic force microscopy (AFM), a higher-order resonant cantilever which is driven at its second order or even higher-order resonant frequency instead of its first order resonant frequency is proposed. Due to the increase in the frequency and quality factor of the higher-order resonant cantilever, the response time, air damping coefficient are reduced and the detecting sensitivity of the cantilever is improved. Meanwhile, because the angular deflection of the cantilever under higher-order resonant vibration is larger than that under the first order resonant vibration, the optical magnification level of the higher-order resonant cantilever is several times larger than that of the first order when the optical lever method is adopted to detect the variation of the cantilever. Theoretical analysis and experimental results show that the scanning method done by a higher-order cantilever is effective and feasible, and the scanning characteristics of dynamic AFM with the higher-order resonant cantilever are promoted obviously compared with that of the AFM operated in the first-order.

A new 3-PUU parallel CMM is proposed in this paper, and according to kinematic model space coordinate of measuring head is solved with the readings of three grating reading heads. Measuring accuracies affected by errors of parallel structure parameters are mainly analyzed and measuring error model is established. The error analysis interface of measuring head coordinate and data processing results are finished by using Matlab, and based on the results of key errors analysis 3-PUU parallel CMM is further optimized by improving accuracy of manufacturing and assembling workpiece, calibration and error compensation of structure parameters.

The combined measurement technology plays an increasingly important role in the digitalized assembly. This paper introduces a combined measurement system consists of a Laser tracker and a FACMM,with the applications in the inspection of the position of the inner parts in a large-scale device. When these measurement instruments are combined, the resulting coordinate data set contains uncertainties that are a function of the base data sets and complex interactions between the measurement sets. Combined with the characteristics of Laser Tracker and Flexible Articulated Coordinate Measuring Machine (FACMM),Monte-Claro simulation mothed is employed in the uncertainty evaluation of combined measurement systems. A case study is given to demonstrate the practical applications of this research.

Vibration is a source to induce uncertainty for the measurement. The traditional passive vibration control method has low efficiency and limited working conditions. The active vibration control method is not practical for its power demanding, complexity and instability. In this paper, a novel semi-active vibration control technology based on magnetorheological (MR) fluid is presented with dual variable stiffness and damping capability. Because of the rheological behavior depending on the magnetic field intensity, MR fluid is used in many damping semi-active vibration control systems. The paper proposed a structure to allow the both overall damping and stiffness variable. The equivalent damping and stiffness of the structure are analyzed and the influences of the parameters on the stiffness and damping changing are further discussed.

Dynamic measurement normally is point test using sensors such as accelerators. With the development of binocular stereo vision, the full field dynamic measurement becomes possible. However the dynamic measurement based on binocular stereo vision encounters several challenges. One of the major challenges is that the error of dynamical testing using binocular stereo vision is unknown. In this paper, two models of dynamic testing based on binocular stereo vision are established. The proposed models mainly analyze non-synchronized errors in dynamical measurement and can be used to minimize errors for improving the measurement accuracy.

A non-contact surface roughness measurement technique is put forward based on texture analysis of the digital laser speckle pattern coming from a measured grinding surface. The speckle pattern was captured by a digital camera while the grinding metal surface was illuminated by a laser. Then the surface roughness information immerged in the high frequency sub-band of the speckle pattern was extracted with the texture analysis of wavelet transform and Markov Random Fields model. Our research has illustrated that surface roughness Ra has a good monotonic relationship with the texture features of the speckle pattern. If this measuring system is calibrated with the surface standard samples roughness beforehand, the surface roughness actual value Ra may be obtained in the case of the same material surfaces ground at the same manufacture conditions.

The accuracy lives of a measurement system and its components are generally different and it will lead to a waste of resources. In order to make full use of the system’s resources and improve its accuracy life, a novel design method based on uniform accuracy life for measurement systems is proposed in this paper. According to the theory of error decomposition and tracing, Hilbert-Huang transform (HHT) method is employed to decompose the total errors of an error test system for a dial gauge and then the accuracy loss functions for the total system and some error parameters are obtained. Based on the analysis of the transfer function for the accuracy loss between the different parts of the measurement system, a constraint model consisting with the uniform accuracy life principle is set up. Taking the maximum life of the measurement system as the objective function, the uniform design model has been solved by means of the optimization methods. The uniform design method can be used to promote the accuracy life of the measurement system.

This paper raises a new method for evaluating uncertainty that taking count of both the record and the data. By using Bayesian Statistical Principle, the prior distribution and the posterior one, provided by the record and the data, were combined together. The statistical characteristics parameter estimation was descended from the posterior distribution, so that a formula of the uncertainty, which combined the advantages of type A and B, was acquired. By simulation and verification, this measurement shows great advantages compared with the others, especially to small size of data analysis.

Laser interferometers are widely used as a reference for length measurement. Reliable bidirectional optical fringe counting is normally obtained by using two orthogonally sinusoidal signals derived from the two outputs of an interferometer with path difference. These signals are subject to be disturbed by the geometrical errors of the moving target that causes the separation and shift of two interfering light spots on the detector. It results in typical Heydemann errors, including DC drift, amplitude variation and out-of-orthogonality of two sinusoidal signals that will seriously reduce the accuracy of fringe counting. This paper presents a robust sinusoidal signal processing method to correct the distorted waveforms by hardware. A corresponding circuit board has been designed. A linear stage equipped with a laser displacement interferometer and a height gauge equipped with a linear grating interferometer are used as the test beds. Experimental results show that, even with a seriously disturbed input waveform, the output Lissajous circle can always be stabilized after signal correction. This robust method increases the stability and reliability of the sinusoidal signals for data acquisition device to deal with pulse count and phase subdivision.

Digital Speckle Pattern Interferometry (DSPI) is an optical method for measuring small displacement and deformation. It allows whole field, non-contacting measurement of micro deformation. Traditional Temporal phase shifting has been used for quantitative analyses in DSPI. The technique requires the recording of at least three phase-shifted interferograms, which must be taken sequentially. This can lead to disturbances by thermal and mechanical fluctuations during the required recording time. In addition, fast object deformations cannot be detected. In this paper a DSPI system using Spatial Carrier Phase Shifting (SCPS) technique is introduced, which is useful for extracting quantitative displacement data from the system with only two interferograms. The sensitive direction of this system refers to the illumination direction and observation direction. The frequencies of the spatial carrier relates to the angle between reference light and observation direction. Fourier transform is adopted in the digital evaluation to filter out the frequencies links to the deformation of testing object. The phase is obtained from the complex matrix formed by inverse Fourier transform, and the phase difference and deformation are calculated subsequently. Comparing with conventional temporal phase shifting, the technique can achieve measuring the vibration and transient deformation of testing object. Experiment set-ups and results are presented in this paper, and the experiment results have shown the effectiveness and advantages of the SCPS technique.

The measurement of miniature components with a micro- or nano-coordinate measuring machine requires a high precision contact scanning probe. The elastic mechanism of low stiffness is a major component of the contact scanning probe. A new elastic mechanism is analyzed by the theory of elasticity and finite element analysis in this paper. It is to realize the probe’s mechanical behavior and stiffness when designing an elastic mechanism for a contact scanning probe. The contact scanning probe is composed of a tungsten stylus with a ruby ball tip, a mechanism of floating plate suspended by four V-shaped leaf springs, and a 3D optical sensor. The leaf spring experiences elastic deformation when a contact force is applied. Uniform stiffness model is analyzed. Simulation and experimental results verify the correctness of the analysis.

Infrared thermometer could provide IR radiance information to get the corresponding temperature as the machine is working. But the emissivity coefficient, which converts IR radiance to temperature, would vary with change of surface properties during rubbing, and this would bring dynamic error in measurement. In this study, we introduced a special tester, in the side of which compact IR thermometer are mounted. The thermometer enables us to measure contact surface temperature directly during tests of a rotating ring and a flat block which had a laser diode fixed under its contact surface. Based on Kirchhoff theory, the calculate model of the spectral emissivity is constructed. The normal emissivity at target region are measured through trigonometric ray consisted of InGaAsP laser source, PbSe detector and objective surface. So the temperature value from the IR thermometer could be corrected dynamically according to the real-time emissivity. The structure and the principle of the apparatus are described. The key technologies and the corresponding solution methods are briefly discussed. The error due to the rapid variations of emissivity value with change in contact conditions was shown, and it must be taken into consideration in radiometric temperature measurement in rubbing and could be especially useful in the verification of friction surface temperature predictions.

In order to meet the needs of sintering optical fiber probe, a discharging device based on CA1524 is presented in this paper. First the direct current (DC) is converted into the high-voltage alternating current by push-pull power amplifier circuit. Then we can get more than 2000 V DC by voltage doubling and rectifying, and it is connected to the electrode rod for high-voltage discharge. LPC1768 is used to control the duty cycle of CA1524, which can regulate the discharge intensity; the discharge time is controlled by the LPC1764 and CA1524.

There are two kinds of methods to measure the bidirectional reflectance distribution function (BRDF), direct method and relatively method. The relatively method is widely used because of its convenience and small error. However, the BRDF of the Spectralon white reflectance standard in relatively method was found to deviate from the Lambertian BRDF. It was found to vary with the angle of incidence, the wavelength of incidence and the states of polarization of the incident and reflected light. This paper proposes an optimized measurement formula of BRDF. The result is corrected. Taking the BRDF of standard roughness specimens for example, experimental results show that the measurement accuracy is improved comparing with the original formula. Finally the error analysis is carried out on the accuracy of measurement. The research has certain reference significance for the study of target characteristics on non-cooperative target ranging.

In view of present problem of low accuracy, limited range and low automaticity existing in the large-scale diameter inspection instrument, a precise measuring system (robot) was designed based on laser displacement sensor for large-scale inner diameter in this paper. Since the traditional measuring tool of the robot is expensive and hard to manufacture, an indirect calibration method is proposed. In this study, the system eccentric error is calibrated by ring gauge of laboratory. An experiment, which changes the installed order of located rods to introduce located rods’ eccentric error, is designed to test whether the spindle eccentric error remains unchanged. The experiment result shows the variation of spindle’s eccentricity after changing rods is within 0.02mm. Due to the spindle is an unchanged part of robot, based on Φ584 series robot calibrated by ring gauge, other series robot can be deduced combining with the length of extended arm.

Robot parameter errors are mainly caused by the kinematic parameter errors and the moving angle errors. The calibration of the kinematic parameter errors and the regularity of each axis moving angle errors are mainly researched in this paper. The errors can be compensated by the error model through pre-measurement. So robot kinematic system accuracy can be improved in the case where there are no external devices for real-time measurement. Combination measuring system which is based on the laser tracker and the biaxial orthogonal inertial measuring instrument is designed and built in the paper. The laser tracker is used to build the robot kinematic parameter error model which is based on the minimum constraint of distance error. The biaxial orthogonal inertial measuring instrument is used to obtain the moving angle error model of each axis. The model is preset when the robot is moving in the predetermined path to get the exam movement error and the compensation quantity is feedback to robot controller module of moving axis to compensation the angle. The robot kinematic parameter calibration bases on distance error model and the distribution law of each axis movement error are discussed in this paper. The laser tracker is applied to prove that the method can effectively improve the control accuracy of the robot system.

A novel fiber-optic interferometer fringe projector with the sinusoidal phase-modulating method is presented. The system utilizes the integrating bucket method to detect the desired phase or the displacement and a CMOS image sensor to detect four frames obtained by integration of the time-varying intensity in an interference image during the four quarters of the modulation period. Since this technique with the method modulating the injection current of the piezoelectric transducer (PZT), measurement accuracy is not affected by an intensity modulation that usually appears in the current modulation. The system also utilizes the Fresnel reflection signal to adjust the phase-modulation coefficient z to eliminate the disturbance of initial phase ψ0 . The experimental results for surface profiles of a convex hull show that the sinusoidal phase modulating interferometer proposed here confirms its applicability to practical application.

Atomic force microscope is one of indispensable measurement tools in nano/micronano precision manufacture and critical dimension measurement. To expand its industry application, a novel head and system are newly designed combined with Nanosensors cooperation’s patented probe — Akiyama probe, which is a self-sensing probe. The modal analysis and resonance frequency are obtained by finite element(FE) simulations. Using the Locked-in amplifier, the effective and available signal can be abtained. Through the experiment analysis, the retracting and extending curve reflects the tip and sample interaction. Furthermore, the measurement on the calibrated position system demonstrates that the whole system resolution can reach the nanometer scale.

In this paper, we design a phase modulation dynamic AFM measurement system based on the characteristics of the novel tuning fork probe. The AFM head based on the tuning fork probe can work cooperatively with the displacement positioning platform driven by the piezoelectric actuators to achieve the feedback in z direction. The large range nanometer positioning stage can be used to scan the sample in x and y directions. With nanoscale resolution, the whole system has a range of 25mm×25mm in horizontal. The measurement data can be traced back to the definition of meter through three embedded laser interferometers. We measure the internal working current of the tuning fork by experiment, and gain the electro-mechanical coupling factor of the probe, and achieve the calibration of AFM head. To guarantee the system’s feasibility, the AFM measuring system accomplishes the measurement of typical grid structure’s surface morphology in phase modulation mode.

Vibration isolation system is a prerequisite to achieve high resolution picture using scanning tunnel microscope (STM). The principle of spring damping isolation, staked flat-elastomer isolation, pneumatic isolation, and sandbox damping isolation is introduced. The relationship between resonant frequency of the isolation and the effect is presented. The four resonant frequencies are calculated through Finite Element Analysis (FEA). The four vibration isolations is designed and optimized according to the analysis. The experimental results show that spring damping isolation has the best effect and a transfer ratio of 10^-6(120dB) can be obtained.

Phase-sensitive Optical-Time-Domain Reflectometry (OTDR) system is a typical distributed fiber-optic sensing technology to detect and locate multiple dynamic disturbances from the outside, which provides a cost-effective and highly sensitive solution especially for monitoring long or ultra-long perimeters. However, the system is liable to be interfered by laser frequency drifts and environmental noises due to its phase sensitivity. The fluctuant and time-varying backgrounds severely obscure real intrusion signals, which always cause bad detection results or high Nuisance Alarm Rates (NARs). In this paper, an effective signal separation method is proposed to extract true intrusion information from the complicated noisy backgrounds of phase-sensitive OTDR system. The sensing signal in the time-domain at each spatial point is obtained by accumulating the changing trails at different moments. Multi-scale wavelet decomposition is employed on the temporal signal to get the detailed components at different scales. By selectively recombining the scale components, it can easily extract the real intrusion signal, and separate the fluctuant frequency-drift induced phase noises, and the time-varying sound or other interferences caused by the air movements, which are respectively located at different time-frequency components. Moreover, the experimental results show that the event type could be divided and discerned from the time-frequency energy distribution at different scale. Thus nuisance and false alarms in practical applications of phase-sensitive OTDR system can be decreased significantly by this way of signal separation and extraction. This technique provides a useful solution for the intrusion detection and identification of the phase-sensitive OTDR in complicated environments, and paves the way for many important applications such as long perimeter security, oil or gas pipe safety monitoring, large-scale structure health detection and fault diagnosis and so on.

For measuring the surface profile of many micro-optical components which are made of non-conductive material, such as diffractive grating and Fresnel lens, with complicated shapes on their surfaces, the electrostatic force microscopy (EFM) was recommended in noncontact condition. When a bias voltage is applied between the conducting probe tip and a back electrode where a non-conducting sample was put on, an electrostatic force will be generated between the probe tip and the sample surface. The electrostatic force will change with the distance between the probe tip and the sample surface. Firstly, the relationship between the electrostatic force and the tip-sample distance was analyzed based on the dielectric polarization theory. The theoretical result shows that the electrostatic force is proportional to 1/d², where d is the distance between the probe tip and sample surface. Then, a numerical method (finite element method -FEM) was employed to calculate the electrostatic force and the result shows accordance with the theoretical method. Finally, the prototype of a scanning electrostatic force microscopy was built which is composed of a conducting probe unit with a Z scanner driven by piezoelectric actuators, a XY scanner unit for mounting the sample and back electrode and a circuit unit for detecting the frequency shift. The force curve, which shows the relationship between the electrostatic force and the tip-sample distance, was achieved by using the EFM prototype. All results demonstrated that it is feasible for using the EFM system to measure the surface profile of non-conductor.

A method is introduced for calibrating the kinematic parameters of articulated arm coordinate measurement machines (AACMM) to improve its accuracy. The kinematic model of AACMM is firstly built according to Denavit-Hartenberg method. Then specific kinematic parameters and the errors of which are analyzed. A nonlinear programming genetic algorithm is adopted to seek the global optimal solution of the kinematic parameters. Computation result indicates that the method can be used to implement the calibration precisely and quickly.

Because of the shortcomings of the main methods used to analysis single cell, the need of single living cell analysis with no damage, unmarked and in situ dynamic multi-parameter measurement is urgent in the life sciences and biomedical advanced research field. And the method of for living cells analysis is proposed. The spectral pretreatment technology of living cell is the key work of laser confocal Raman spectroscopy. To study the spectrum processing methods for Raman spectrum on single living cell and develop the pre-process techniques to enhance the signal-to-noise ratio, sensitivity, and decrease the influence of fluorescence, elimination the cosmic rays was used to improve the spectrum. The classification, average and filtration of spectrum were applied to enhance signal-to-noise ratio. The fluorescence was depressed for quantity analysis or utilized for analysis by comparing the background and the spectrum. The results show that the proposed technique for laser confocal Raman spectrum of single cell can perform the sensitive and weak intensity peaks and reflect the information of molecules structures very well.

An all fiber Q-switched Ytterbium-Doped Fiber （YDF） laser in Master Oscillator Power-Amplifier (MOPA) configuration is proposed theoretically and demonstrated experimentally, and the principle analysis and experimental verification are presented in details. Firstly, the system configuration is designed. The system is composed of the seed and the amplifier stage. Two 915nm LDs are used for pumping light, and the light is coupled into the gain medium of the seed and the amplifier stage by two combiners, respectively. Two Fiber Bragg Gratings (FBGs) are used as ends of the cavity of the seed. One Q-switch is used to modulate output laser of the seed, and the amplifier stage is adopted to amplify the light behind the seed. Then, 10m YDF with single mode is selected for the gain medium of the seed, and 8m YDF with multimode is used as the gain medium of the amplifier stage. The output laser of the seed with a 1.02W average power is realized when the seed pump power is 5.74W, the repetition rate is 20KHz and the action time of the Q-switch is 3.5μs. Meanwhile, a 7.58W pump power of the amplifier stage is used to amplify the seed laser. Finally, output laser with the pulse width of 90ns and the average output power of 4.93W are achieved.

With the aim to get harmonic distortion characteristics and frequency components of modulated output signals of a Mach-Zehnder (MZ) intensity modulator, this paper analyzes the optical intensity modulation transfer function by Tailor expandsion method according with the working principle of modulator. From the viewpoint of spectrum, the output signal is mainly comprised of the fundamental harmonic, the second intermodulation harmonic and the third intermodulation harmonic of the input signal and their magnitudes are connected with the bias voltage and Eigen-phase of MZ modulator. The second harmonic distortion and the fundamental harmonic of the modulated output signal are closely related with the drift of the best bias point. When the modulator works at the best DC bias voltage point, the modulated output signals have the minimum second harmonic distortion. If the best bias point drifts, the second harmonic distortion increases and the fundamental harmonic decreases, which changes in proportion to the sine or cosine of the drift voltage. A 1GHz sine signal with 1V amplitude imposed on the modulator, the simulation results by MATLAB presents that the waveform starts distorting along with the drifting of the best bias voltage, which the fundamental wave component starts decreasing and the second harmonic component starts increasing. While at last the fundamental wave component is zero, the frequency of output modulated signal doubles as much the frequency of input signal.

Laser diodes (LD) are used extensively in fiber lasers as pump sources. The operating characteristic of laser diodes determines a requirement of constant current regulation, high stability and high current in the drive circuit. This paper gives a design of constant current source aiming at the drive circuit of fiber laser pump sources with 24 volt power supply. It is made up of Buck module and constant current module. The synchronous Buck module consists of the chip LT3743, MOSFET Si7848BDP and RJK0330DPB, with the advantages of high-current output, low dissipation power and high power-supply efficiency. Circuit simulation results are given by the simulation software LTspice. It is shown that the Buck module satisfies the need of the circuit.

It would be very challenging for a designer to select desirable structure parameters for a laser triangulation probe, the parameters which have an appreciable or noticeable impact on probe’s measuring range, resolution and accuracy. The challenge is aggravated by the trade-offs between the measuring range and resolution since there is interdependency and a delicate balance among them. Therefore, this paper focuses on building the relationship between the measuring range and resolution, and tries to optimize the structure parameters to improve measuring accuracy within a certain measuring range. In order to verify the validity and feasibility of this method, single-triangulation probe simulation experiments are also performed in 3dsmax platform. In addition, a double-triangulation probe simulation system is proposed and the experimental results confirm that the slope error can be compensated effectively. The conclusions presented in this paper provide useful guidance for designing a high-precision triangulation probe.

Digital holographic interferometry (DHI) is a well-established optical technique for measurement of nano-scale deformations. It has become more and more important due to the rapid development of applications in aerospace engineering and biomedicine. Traditionally, phase shift technique is used to quantitatively measure the deformations in DHI. However, it cannot be applied in dynamic measurement. Fourier transform phase extraction method, which can determine the phase distribution from only a single hologram, becomes a promising method to extract transient phases in DHI. This paper introduces a digital holographic interferometric system based on 2D Fourier transform phase extraction method, with which deformations of objects can be measured quickly. In the optical setup, the object beam strikes a CCD via a lens and aperture, and the reference beam is projected on the CCD through a single-mode fiber. A small inclination angle between the diverging reference beam and optical axial is introduced in order to physically separate the Fourier components in frequency domain. Phase maps are then obtained by the utilization of Fourier transform and windowed inverse Fourier transform. The capability of the Fourier transform DHI is discussed by theoretical discussion as well as experiments.

A kind of circuit characterized by sampling, amplifying and adjusting light pulse was introduced. It can be applied to the real-time monitoring of narrow light pulse. Theoretically, the paper analyses the relationship between the pulse slewing rate and the selection of an amplifier, also the relationship between the bandwidth of the retainer and the selection of a hold-capacitance is deduced. The main performance of the peak holder is analyzed and the method of selecting amplifier and holding-capacitance is introduced. According to the theoretical analysis, high-speed, weak light-pulse signal sampling and peak-holding circuit is designed. PIN diode connected a 50 ohm resistor is used to convert electric current to voltage. The AD8009 voltage amplifier brings about amplifying voltage from 1V to 3V. Sampling and broadening peak can be achieved by OPA615. The excellent EP2C5T144 in the control field is qualified to provide a control signal, which is able to control the conversion of peak sampling or holding. Therefore, the amplification and broadening of narrow pulse signal are obtained. This light power signal pulse width is 100 ns, with 50 ns rising time and 50 ns falling time. Light power signal varies from 0.1w to 1w. The current signal from PIN diode is 1~10 mill ampere (mA). This circuit is effective for the signal of 100 ns pulse width and 50 ns rising time. It is proved that the scheme is feasible and this circuit-design can be used in practical application.

The precision of centroid location for infrared LED point images is an important factor, which affects the precision of the light-pen Coordinate Measuring Machining (CMM) .In this paper, the error model using the traditional center of mass (COM) algorithm is analyzed and it is shown that there are systematic error and random error. This paper analyzes the systematic error and random error, and then adopts the Gaussian surface fitting (GSF) algorithm and weighted centre-ofgravity (WCOG) algorithm to compensate systematic errors, meanwhile it analyzes how to reduce random error. The simulation results show that the accuracy of the infrared LED point position can be enhanced from 1/ 20 pixel to 1/100 pixel using the new algorithm.

The acousto optic modulator drive is mainly made with 2 amplitude shift keying (2ASK)circuit, pre-amplifier circuit and power operational amplifier circuit, and the simulation of the acousto optic modulator drive is realized. Firstly, the acousto optic modulator drive works as follows.The modulation function is realized by the analoged switch circuit, and the on-off of the analoged switch chip (CD4066) are controlled by the pulse signal generated by the electronic conversion circuit. The voltage amplification of the modulated signal is achieved by two reverse proportional operation implements voltage amplifier circuit, and the circuit is mainly made with the AD8001 chip. Then the amplified signal is transfered into a two–stage power operational amplifier circuit of class C which is mainly made with the chip of MRF158. Secondly, both of the simulating structures and the union debugging based on the designed system are realized by Multisim. Finally, obtaining the modulation signal of 150(MHz) frequency and 5(μs) pulse width illustrates that a 2ASk modulation of the 150 (MHz)carrier signal and the 20(kHz) modulation signal is achieved. Besides, as the frequency of input signal and amplitude of voltage change, the output power of the power operational amplifier circuit also changes, and the conclusion is drawn that the output power increases when the frequency of input signal decreases and the amplitude of voltage increases. The component selection of the drive’s PCB design, the performance parameter and of the actual circuit and the debugging of the actual circuit are based on the simulation results.

Determination of image point coordinates has a strong influence on the accuracy of photogrammetry. It will be helpful if we could choose a kind of locating method with highest accuracy in specific environment. As it is difficult to measure the image point location accuracy directly, researchers generally acquire this accuracy by simulation which may deviate greatly from real environment. This paper proposes a more practical method - to evaluate the accuracy of image point center location from practical scenario based on linear fitting. This method promises to evaluate a higher accuracy in the image space via a lower accuracy in the object space through projection rules. In this paper we perform an experiment with retro-reflective targets (RRT), a coordinate measuring machine (CMM) and a CCD camera. The target locations are centroid, squared centroid and ellipse fitted center. Their accuracy, in descending order, is: squared centroid, centroid, and ellipse fitted center.

Different package of fiber Bragg grating (FBG) temperature sensors were introduced. The temperature sensitive factors of the sensors were derived analytically and verified by experiments. A quasi distributed temperature sensor system consisted of different-packaged FBG, wideband light source, and FBG interrogator was set up successfully. The experiment results of the different FBG temperature sensors were compared by analyzing the variety properties of center wavelength in identical conditions. From the experimental results, it is shown that the central wavelength of FBG temperature sensor with different package shifts diversely; while good linearity and preferable repeatability are present among the various FBG sensors, and there is almost no hysteresis effect. The temperature sensing ability of the packaged FBG sensor is improved and the temperature sensitivity coefficient is about 3 or more times as much as that of the bare FBG. The temperature resolution of the packaged FBG sensor can reach up to 0.03°C. It is indicated that all the packaged FBG sensors are suitable to measure temperature according to specific application environment.

Optical tweezers based on cylindrical vector beams are studied theoretically and experimentally. First, we present the basic concept of a cylindrical vector beam (CVB), whose polarization is axially symmetric to the optical axis. Second, two theoretical modes to analyze the interaction between the light beam and the particle are introduced, respectively, and some simulations have been shown. Then, the system structure and its operation principle are introduced in details, where a spatial light modulator (SLM) is used to flexibly generate the CVBs, and experimental results are also demonstrated, which show some advantages for optical manipulation of particles using CVBs.

A new laser confocal focal-length measurement (LCFM) is proposed for the high-accuracy measurement of lens back focal length. LCFM uses the peak point of confocal response curve to precisely identify the lens focus, and uses the elastic contact between reflector R and the lens last surface to determine the test lens last vertex. The distance between the reflectors on these two positions is then measured by a laser distance interferometer, and then the accurate back focal-length of test lens is obtained. Compared with existing methods, LCFM significantly improves the measurement accuracy and simplifies the system structure by laser confocal technique, and reduces the product development cost. LCFM is especially suitable for the back focal-length measurement of large aperture lens.

During the calibration of optical microscopic image measurement system, how to quickly and accurately extract the feature point coordinates from micro image of calibration sample is the key factor to affect the calibration precision. Microscope calibration has unique characteristics that are quite different from traditional camera calibration. In this paper, a method for extracting feature points of micro calibration sample is provided based on the analysis of microscope calibration system and calibration sample. The method preprocesses the micro image with threshold segmentation, dilation, erosion and other operations; then labels connected components and computes the coordinates of the feature points by computing centroid of image connected regions. The experiment results show that this method can quickly and efficiently obtain the coordinates of the feature points.

This paper proposes a new method which is called variable weighted centroid method for locating the center of retro reflective target. It is based on centroid method. This method adapts itself to different measurement environments by varying the weight coefficients α, which is determined by different factors associated with measuring environment. The coefficient α is optimized by experiment. The evaluation criterion (lower is better) under the proposed method is reduced by at least 25% compared with the traditional method. Experiment results show that this variable weighted centroid method provides higher locating accuracy than old methods.

In cases when it is necessary to lock optical frequencies generated by an optical frequency comb to a precise radio frequency (RF) standard (GPS-disciplined oscillator, H-maser, etc.) the usual practice is to implement phase and frequency-locked loops. Such system takes the signal generated by the RF standard (usually 10 MHz or 100 MHz) as a reference and stabilizes the repetition and offset frequencies of the comb contained in the RF output of the f-2f interferometer. These control loops are usually built around analog electronic circuits processing the output signals from photo detectors. This results in transferring the stability of the standard from RF to optical frequency domain. The presented work describes a different approach based on digital signal processing and software-defined radio algorithms used for processing the f-2f and beat-note signals. Several applications of digital phase and frequency locks to a RF standard are demonstrated: the repetition (f_rep) and offset frequency (f_ceo) of the comb, and the frequency of the beat note between a CW laser source and a single component of the optical frequency comb spectrum.

We present method of measurement of fiber Bragg gratings (FBG) stretching by laser interferometer. We are oriented to research, development and to methodology of the production and application of FBGs. The elongation of FBGs can calculated from frequency drift of the Bragg resonance wavelength and from the change of the grating period during stretching. The inhomogeneity of optical fibers and of the FBGs can induce change of the grating period (Bragg resonance wavelength) of FBG which can be nonlinear with elongation of the optical fiber with FBG. The calibration of FBGs will be used to preparation and to the realization of the technology of measurement of shape deformation of concrete buildings.

We present an interferometric technique based on differential interferometry setup for measurement in the subnanometer scale in atmospheric conditions. The motivation for development of this ultraprecise technique is coming from the field of nanometrology. The key limiting factor in any optical measurement are fluctuations of the refractive index of air representing the greatest source of uncertainty. Our proposal is based on the concept of combining overdetermined interferometric setup where a reference wavelength is derived from a mechanical reference for compensation of fast fluctuations and traditional indirect evaluation of the refractive index compensating on the other hand the long-term drift of the mechanical reference caused by thermal expansion. The technique allows to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third evaluates the changes in the measuring range acting as a tracking refractometer. The principle is demonstrated on an experimental setup and a set of measurements describing the performance is presented.