The development of a digital micro-holo interferometric system is presented in this paper. With respect to the specific requirements on the microscopic scheme in micromeasurement, application of long distance microscope is introduced with emphasis. With its corporation, the achievable microscopic resolution is studied and demonstrated by the use of the standard resolution test target. Experiments are performed to testify the capacity of the proposed system in resolving structures with lateral dimensions at the micro level. A critical issue, validation of the developed system is also addressed. Aided by finite element analysis and analytical calculation, experimental measurement with the system is addressed. Aided by finite element analysis and analytical calculation, experimental measurement with the system is examined using a hybrid approach. To evaluate the performance of the system, microbeam experiment is presented. Results measured with the system, as well as the numerical simulations are obtained. Quantitative comparisons are carried out in terms of load-induced variations of the test sample, based on which the conclusions are given.

Recent technological trends based on miniaturization of mechanical, electro-mechanical, and photonic devices to the microscopic scale, have led to the development of microelectromechanical systems (MEMS). Effective development of MEMS components requires the synergism of advanced design, analysis, and fabrication methodologies, and also of quantitative metrology techniques for characterizing their performance, reliability, and integrity during the electronic packaging cycle. In this paper, we describe opto-electronic techniques for measuring, with sub-micrometer accuracy, shape and changes in states of deformation of MEMS strictures. With the described opto-electronic techniques, it is possible to characterize MEMS components using the display and data modes. In the display mode, interferometric information related to shape and deformation is displayed at video frame rates, providing the capability for adjusting and setting experimental conditions. In the data mode, interferometric information related to shape and deformation is recorded as high-spatial and high-digital resolution images, which are further processed to provide quantitative 3D information. Furthermore, the quantitative 3D data are exported to computer-aided design (CAD) environments and utilized for analysis and optimization of MEMS devices. Capabilities of opto- electronic techniques are illustrated with representative applications demonstrating their applicability to provide indispensable quantitative information for the effective development and optimization of MEMS devices.

Thermo-mechanical reliability is a key issue of IC packaging. In this paper, the chemical shrinkage stress caused by the underfill curing is quantitatively investigated: DSC test result provides the basis for the determination of temperature profile for the curing of underfill. The 3D deformation of the flip chip during the underfill curing process is measured with 3D Moire interferometry system. Also a simple theoretical model is set up for this problem, DMA test provide the necessary parameters for this model. The experimental and theoretical results agree well with each other, both results show that the chemical shrinkage stress is fairly small when compared with the thermal residual stress, so this part of residual stress can be neglected in the commonly used finite element analysis (FEA) model.

Competitive trends to miniaturize Micro Electro Mechanical (and Optical) Systems (MEMS, MOEMS), electronic components and assemblies introduce unprecedented requirements concerning their design, manufacturing and testing. The paper presents a concept of digital holographic microinterferometrer (DHMI) for microelement deformation testing. DHMI may provide all components of the displacement vector and work with reflecting and scattering surfaces of object under test. For numerical reconstruction of digitally stored holograms a new method based on the sphere transformation theory is applied. It significantly simplifies the analyses in comparison with a conventional method directly based on the Fresnel approach. The algorithms proposed enable fast and high accuracy measurements. In the paper the practical realization of DHMI is presented. The measurement methodology is shown on the example of deformation testing of pressure loaded silicon micromembranes. The results were used for verification of micromembrane modeling by FEM.

The general concept of 3D data acquisition and processing system, which enables gathering information about shape, morphing and movement of 3D object for virtual environment, is presented. The methodology based on combined structured light, spatio-temporal phase analysis and photogrametry is described. For VR the concept of a virtual camera, as the mean for interactive object visualization is introduced. The exemplary, initial results of implementation of such system are presented.

A new, miniaturized fringe projection system is presented which has a size and handling that approximates to common 2D cameras. The system is based on the fringe projection technique. A miniaturized fringe projector and camera are assembled into a housing of 21x20x11 cm size with a triangulation basis of 10 cm. The advantage of the small triangulation basis is the possibility to measure difficult objects with high gradients. Normally a small basis has the disadvantage of reduced sensitivity. We investigated in methods to compensate the reduced sensitivity via setup and enhanced evaluation methods. Special hardware issues are a high quality, bright light source (and components to handle the high luminous flux) as well as adapted optics to gain a large aperture angle and a focus scan unit to increase the usable measurement volume. Adaptable synthetic wavelengths and integration times were used to increase the measurement quality and allow robust measurements that are adaptable to the desired speed and accuracy. Algorithms were developed to generate automatic focus positions to completely cover extended measurement volumes. Principles, setup, measurement examples and applications are shown.

The shoeprint impressions of suspect left at the crime scene can sometimes tell investigators what type of shoes to be looked for. These shoeprint impressions as one of the important evidence are useful in the detection of criminals. In this paper we propose a novel technique for identifying and analyzing the 3D characteristics of shoeprint impressions. We also design 3D shoeprint impression analysis system based on the combination the 3D shape measurement with structured illumination and fringe pattern analysis. We give a detail discussion on the principle and configuration of the system. Laboratory experiments show the technique is efficient in the detection of shoeprint and in the offering the reference for judicial evidence.

In medicine, a change in the documentation of rendered services and therapeutic results is currently taking place. Previously, simple standards were sufficed to document the quality and effectiveness of a treatment. In the case of surgical and dermatological treatments, the therapy was initiated according to diagnosis and indication and ended with a histological examination and confirmation of the diagnosis by the pathologist. Newer therapeutic methods, e.g., laser surgery, conservatively treat and remove pathological changes in the skin surface, without the possibility of sending a specimen to the pathologist. Diagnostics must therefore be capable of documenting the dynamic effects of the treatment in the initial phase and subsequent development of the disease. To make it possible to achieve this goal, fast and exactly working 3D invivo measurement methods are necessary, which permit a direct access to the three-dimensionality of the human skin surface. With the digital fringe projection based on micromirror projectors from the Texas Instruments company and the PRIMOS technology, respectively, a new optical 3D measurement method is presented, which makes it possible to measure human skin surfaces fast and very accurately both in the micro and macro-ranges and to document treatment results objectively.

Procedures for measuring the three-dimensional shape of objects using fringe projection are well known for many years. Those systems are suitable for instance for quality control and reverse engineering. For recognition and visualization of objects it's necessary to obtain the shape and also the color and/or the texture of the object's surface. Furthermore, in quality control like defect identification the color information of the surface can be useful. But the use of color cameras to capture all data has the lack of lower resolution or lower frame rates and may cause problems while measuring the shape (with one chip cameras) because different colors are recognized by different pixels looking on different points of the surface. This will cause measurement errors. Here we propose a method basing on the fringe projection technique, which is able to determine the 3-D co-ordinates as well as the color at all measurement points while using only black/white cameras. The main advantage of this method is that color and shape are obtained together with the same (high resolution) camera and that the shape and color information are put together without any matching procedures and are obtained within the same measurement. For this the object is illuminated within the same projection sequence with non structured full frame colored light, e.g. red, green, blue and the well known fringe patterns. As the final result one gets at each measurement point three co-ordinate values containing the position and three-color values containing the real color.

The paper is structured as follows: After some general statements, we will discuss types of aspheres, then typical applications for aspheres, general aspects of interferometric methods for measuring aspheres, special methods for weak aspheres, permutation methods for mathematically simple aspheres, compensation optics, traceable methods, and at the end other methods.

For evaluating the surface of parabolic mirror (90 mm, F/0.76), two different null test have been discussed. After designing, encoding, and fabricating the CGH(computer generated hologram), the null CGH test was performed. An autocollimation test with a flat mirror was also performed and these testing result were compared.

We describe techniques for measuring step heights between separated, nominally plane-parallel surface regions of a precision-engineered part. Our technique combines a broadband, 10-micron wavelength scanning interferometric profiler with a HeNe laser displacement gage. The infrared wavelength accommodates machined metal parts having a surface roughness in excess of what would be possible with a visible-wavelength interferometer. The combination of broadband interferometry, which removes fringe order ambiguity, with a laser displacement gage makes it possible to determine the relative heights of surfaces separated by several mm with a 2-σ uncertainty of 0.3 micron. We present the instrument theory, experimental implementation and results of instrument testing.

An external cavity diode laser is used as source for a frequency modulated continuous wave (FMCW) interferometer intended to determine absolute optical path differences (OPD) of up to 3mm with a target accuracy of 0.3 microns. This interferometer will eventually be paired with a heterodyne interferometer to extend the accuracy of the system to 0.1nm. Rather than using injection current modulation for the FMCW subsystem, the frequency sweep is provided by moving a mirror of the external cavity with a piezo element. A noise source analysis for this particular setup is provided, and estimates of the maximum attainable accuracy are made.

This paper discusses progress in using spatial light modulators and interferometry to control the beam profile of an optical tweezers. The approach being developed is to use a spatial light modulator (SLM) to control the phase profile of the tweezers beam and to use a combination of the SLM and interferometry to control the intensity profile. The objective is to perform fine and calculable control of the moments and forces on a tip or tool to be used to manipulate and interrogate nanostructures. The performance of the SLM in generating multiple and independently controllable tweezers beams is also reported. Concurrent supporting research projects are mentioned and include tweezers beam scattering and neural-net processing of the interference patterns for control of the tweezers beams.

Micro-cylinder lenses are used in beam shaping applications for laser light emitted by semiconductor laser bars. The radiation pattern is extremely asymmetric concerning the angle characteristic. There is a fast and a slow axis of the radiation field. The micro-cylinder lenses are mainly used to correct the fast axis field which makes high numerical aperture lenses necessary. The interferometric test of such fast cylinder lenses is rather involved especially since a deviation from circular symmetry of the meridian curve is mandatory in order to correct the on-axis aberrations. There is a need for surface testing during the manufacture process and performance testing in the final use of the lenses. Surface testing should be done in reflected light. We propose the use of a grazing incidence interferometer based on two diffractive optical elements as beam splitter and beam shaper. With this method arbitrary cylindrical surfaces can be measured with a repeatability of about 10nm rms. The performance test relies on interferometric measurements in transmitted light. To enable a null test a null lens or a diffractive null element is necessary. We report on a null test in transmitted light using a high aperture diffractive element at a wavelength of 780 nm.

The collimation of strongly diverging laser beams emitted by diode lasers is performed with aspherical micro-optical components. In order to obtain a good beam profile high-quality micro-lenses with a large numerical aperture compared to conventional lenses have to be applied. The characterization of these components using conventional interferometric techniques is not suitable, costly or inaccurate with respect to the required accuracy of the lens shape. Digital Holography as a measurement tool for the characterization of micro-optical components offers several advantageous properties with respect to other interferometric techniques, such as avoidance of aberrations introduced by imaging and magnification optics. The large numerical aperture of the microlenses under test leads to high fringe densities in the holograms which can not be resolved by CCD-detectors. In order to avoid this problem digital holography is combined with multiple wavelength and speckle techniques. A diffusing screen is placed directly behind the microlens in order to destroy the large divergence and at least two measurements with different wavelengths are performed for the recovery of the wavefront information. The speckle pattern in the numerical reconstruction of the wavefront reduces the accuracy of the resulting difference phase significantly. In this paper a technique for the reduction of speckle noise is proposed which is not based on classical filtering techniques such as median filters. Several holograms of the same object under test are recorded with different speckle patterns. A proper averaging taking into account the properties of the wrapped phases leads to a improvement of the accuracy up to 1/60 of the wavelength. Results of the characterization of aspherical microlenses using the new technique are presented.

Computer-generated holograms (CGHs) are increasingly used in optical shop testing, especially for testing aspheric surfaces. For precise interferometrical measurements the error influence of the CGHs must be known and needs to be characterized. Different error types of two-level binary CGHs are identified and their contribution to the reconstructed wavefront are discussed: pattern errors of the CGH structure, duty cycle errors, surface figure errors of the CGH-substrate, etching depth variations in phase holograms and thickness variations of the chromium layer of amplitude chrome-type holograms. Methods to determine all these different errors are explained and an error budget of the total CGH error is given. Since the pattern error of a CGH is the most critical error it will be discussed in detail. This error depends on the writing technology (e-beam, laser beam) and on the type of the CGH (inline, off-axis). As examples of the two CGH-types a test method for measuring the pattern errors of Fresnel zone plates and linear gratings is presented. Experimental results of the tests are discussed.

Measurement of shape and deformation of diffusely reflecting surfaces by phase-shifting digital holography is presented that uses an imaging setup. The difference of the reconstructed phases before and after tilt of the object illumination beam provides the contour lines of the surface height, while that before and after object deformation delivers those of object displacement. This method enables measurements of both surface shape and deformation of 3D object of various sizes with the same optical system and the processing software. Suppression of speckle noise is also discussed.

Grating shearography is an extension of moire interferometry where a shearing element is included in the imaging part of the setup. It is possible to obtain all three components of the in-plane strains, the in-plane rotation and the two out-of-plane slopes. The presented application is an experimental investigation of the mechanical behavior of a plain woven graphite fiber reinforced polymer composite lamina under tensile loading.

Fourier transform phase-shifting interferometry is further developed and applied to the absolute measurement of interferometer cavities. Using a widely tunable IR laser diode initially developed for telecom applications along with specific interferometer cavities, I apply this new capability to the measurement of absolute cavity lengths, where a 1-(sigma) precision of 12.6 ppb is demonstrated and the technique was then used to determinate the absolute index and thickness of a transparent parallel plate.

Fourier transform method and phase shift method are widely used to analyze fringe patterns to obtain surface profiles. In these ordinary fringe analysis methods, tilt or angle in the measured surface is often cancelled by certain operations. On the other hand, tilt can be considered as part of the measured surface, and obtained by fitting the measured surface profile with a line or plane. Therefore, we proposed a high-precision angle measurement method using fringe analysis techniques. In this paper, a 2-dimensional angular measurement interferometer is constructed to realize the proposed method, and the output curve of the measurement system is calibrated using a high-resolution autocollimator and a PZT driven lever system as the references. Fringe patterns obtained by the experiments are analyzed by both of the Fourier transform method and phase shift method, and the experimental results are compared with each other. Furthermore, the characteristics of the measurement system, including stability, resolution, and accuracy are evaluated and analyzed. Experiments verified that it could achieve both a wide measurement range of over +/- 2160 arcsec (+/- 0.6Degree) and a high angular resolution of 0.01 arcsec, simultaneously.

Novel applications of computer aided holographic interferometry and electronic speckle pattern interferometry in automotive powertrain engineering are presented. Four applications are described: engine manifold/cylinder head interface deformation measurement, engine camcover strain analysis, throttle bore deformation measurement, and alternator modal characterization.

We report on the development of a versatile and portable optical profilometer and show its applicability for quick and accurate digitization of 3-D objects. The profilometer is an advanced fringe-projection system that uses a calibrated LCD matrix for fringe-pattern generation, a hierarchical sequence of fringe patterns to demodulate the measured phase, and a photogrammetric calibration technique to obtain accurate 3-D data in the measurement volume. The setup in itself is mechanically stable and allows for a measurement volume of about 1x1x0.5 m³. We discuss the calibration of the sensor and demonstrate the process of recording phase data for several sub-views, generating 3-D point clouds from them, and synthesizing the CAD representation of an entire 3-D object by merging the data sets.

We propose an algebraic reconstruction method (ART) based on smooth functions to obtain the refraction index distribution of a radially symmetric phase object. Recovering the refraction index of a transversal section enables us to obtain some other physical variables such as temperature, pressure, etc. Considering phase objects with a radially symmetric distribution allows the recovery of information regarding the volumetric distribution of the refraction index based on a single projection. The proposed method is accurate, faster, and somewhat easier to implement than other currently used ART methods. As a sample application, the proposed method is applied to a burning candle case.

We describe a method for the ultrasonic displacement measurement in a small volume based on self-mixing effect in a laser diode. The interference signal (mode-hop signal) is modulated with injection variation and demodulated by signal analysis. The interference signal due to the vibration of a testing example under the ultrasonic excitation is used for a determination of the sound displacement. Self-mixing interferometer is used, because it is much simper than the conventional interferometers. Many optical elements like the beamsplitter, reference mirror, and external photodetector are not required. Theoretical analysis and experimental method are presented. The vibration of a PZT transducer-driven sample was measured with resolution of sub-micron.

The application of two dimensional addressable high resolution displays as spatial light modulators for the reconstruction of coherent masks is investigated. Based on their amplitude and/or phase modulating properties they are implementable as dynamic diffractive element and thus they are qualified for the efficient reconstruction of digital holograms. Parameters are deduced for a geometrically exact reconstruction of an object-wave field for its use as coherent mask in an interferometric measuring system. Results for different spatial light modulators are presented.

By applying two-reference beam interferometry together with digital data processing, a correspondingly modified double exposure holographic interferometer has been used to measure the density distribution in flow fields generated by very weak shock waves. The weak shock waves were generated by the explosion of milligram charges of silver azide, which were ignited by a pulsed Nd:YAG laser. With the help of this technique, density variations in a flow field associated with a shock Mach number M_s = 1.0007 were visualized and quantified. Phenomena that generated a sound intensity of 135dB could be resolved.

Modern production requires more and more effective methods for the inspection and quality control at the production place. Outsourcing and globalization result in possible large distances between co-operating partners. This may cause serious problems with respect to the just-in-time exchange of information and the response to possible violations of quality standards. Consequently new challenges arise for optical measurement techniques especially in the field of industrial shape control. A possible solution for these problems can be delivered by a technique that stores optically the full 3D information of the objects to be compared and where the data can be transported over large distances. In this paper we describe the progress in implementing a new technique for the direct comparison of the shape and deformation of two objects with different microstructure where it is not necessary that both samples are located at the same place. This is done by creating a coherent mask for the illumination of the sample object. The coherent mask is created by Digital Holography to enable the instant access to the complete optical information of the master object at any wanted place. The transmission of the digital master holograms to this place can be done via digital telecommunication networks. The comparison can be done in a digital or analogue way. Both methods result in a disappearance of the object shape and the appearance of the shape or deformation difference between the two objects only. The analogue reconstruction of the holograms with a liquid crystal spatial light modulator can be done by using the light modulator as an intensity modulator or as an phase modulator. The reconstruction technique and the space bandwidth of the light modulator will influence the quality of the result. Therefore the paper describes the progress in applying modern spatial light modulators and digital cameras for the effective storage and optical reconstruction of coherent masks.

The use of interferometers is usually divided into two areas, single-dimensional length measurement where the distance along an optical axis is measured and interferometric surface or wavefront measurement where the laterally varying phase distribution of a largely extended wavefront is the property of interest. In this presentation a combination of the two types of use will be presented. One of the applications which requires simultaneous measurement of distance, slope and curvature is high-accuracy form measurement of aspheres and free form surfaces by the Large Area Curvature Scanning (LACS) method. For a high-accuracy LACS set-up it is most important to measure (and control) the absolute distance between the interferometer and the surface under test, as well as the slope of the wavefront. In the present set-up, a commercial general purpose interferometer is used. The simultaneous measurement of distance, slope, curvature and shape with this instrument is presented. Special emphasis is laid on the specific fringe evaluation method. It uses a model of the real interferogram image and the superimposed disturbing effects. A suitable global optimization method allows the desired quantities to be determined rapidly and reliably. For the future use of LACS, a new, specifically designed multi-purpose interferometer is introduced which can be used in LACS systems with nanometer form measurement accuracy.

The speckle interferometry is used to measure the shape of an object with a rough surface. In particular, the precise measurement can be easily performed with ESPI using fringe scanning technology. Then, the measurement accuracy is influenced with the ratio between the speckle size and the pixel size of a CCD. Sometimes, this causes the problem concerning an optical dislocation. In this paper, an in-plane displacement is measured by the arrangement using the two collimated beams. The measurement is performed by ESPI technology with the spatial fringe analysis method under the optimal condition. The condition is discussed as the measurement parameters concerning the speckle's size and the passband of band pass filter. In the experiment of the measurement of in-plane displacement, the optimal condition can evade the problem of occurrence of optical displacements. At the same time, the precise measurement can be performed.

A new method of rotating angle measurement with dual-frequency laser interferometry using a grating wedge-plate is described here. A grating wedge-plate is formed by making a reflecting flare grating on a glass wedge-plate. The principle of the grating wedge-plate is introduced and its application in the rotating angle measurement system is provided. The setup and principle of the system are also introduced. This system can be applied not only to small angle measurement but also to dynamic random angle measurement. An experiment of rotating angle measurement is given. The measuring range of angle is up to 360 degree(s) and the measurement accuracy is better than 0.5 arc sec. High precision, stability and immune to errors are the distinguished features of this interferometer.

Phase measuring profilometry using structured illumination with a digital micro-mirror device(DMD) has been extensively studied because of its advantage of the programmable projection. In this paper we discussed the effect of intensity transfer function of the commercial projector with DMD, analyzed the influence of the intensity transfer function and the nonlinear of detector on the quantity of projected sinusoidal fringe and the accuracy of phase measurement, and proposed the correction method for intensity transfer function of DMD. A DMD based phase measuring profilometry system includes a commercial projector with DMD, a CCD camera and a fringe pattern analysis and processing unit. The experiments show that with the correction of the intensity transfer function of the projector the phase measurement accuracy has been improved obviously.

We use the micro-scanning technique to eliminate the frequency aliasing caused by sub-sampling in Fourier trans-form profilometry (FTP). It has been discussed that in FTP correct 3-D surface shape retrieval can be obtained only when the slope of the height variation of the measured object is limited within maximum measurement range. If this condition is not satisfied, it is im-possible to obtain correct retrieval because of shadows existed in the fringe pattern. In a crossed-optical-axes system for FTP, a smaller included angle between axis of the projection and the detection system is set to avoid the frequency alias caused by shadows. But the smaller the included angle is, the lower the phase sensitivity in FTP. That is, a small phase error can cause a large height distribution error. In order to eliminate this kind of error, we should project a dense grating image onto an object to reduce equivalent wavelength of fringe. At the same time, we need a high resolution CCD to record the fringe pattern to satisfy the sampling theory. When there is not suitable high resolution CCD, the sub-sampled fringe is obtained. In this paper, we discuss how to combine a cor-rect fringe from sub-sampling fringe patterns using micro-scanning technique in FTP in theory. Computer simulations experiments have proved our analysis.

We present a possibility of a rapid measurement of the shape of a human face for medical applications (e.g. jaw-measurement) using a method of color coding by stochastically generated fringe patterns. There are no synchronization problems between the source of the fringe patterns and the detectors within the time of measurement (<1s). The experimental error of the reconstructed 3D object is σ _rms<0.1 mm.

A method for measuring the wave front errors and the modulation transfer function (MTF) of the large aperture optics is presented. The large aperture Fizeau interferometer with long optical path difference by using a (phi) 400 mm off-axis parabolic mirror is made. The MTF is measured at the wavelength of the interferometer by changing the laser into the partially incoherent light. A bidirectional shearing interferometer is used for collimation testing. The test results of a (phi) 300 mm Cassegrain type satellite telescope made in Korea are presented.

The entire process of designing the test setup with a computer-generated hologram (CGH) and performing the CGH-null test of an asphere will be described in detail. Critical aspects in testing aspherics with CGH-nulls e.g. caustic of the asphere, influence of alignment errors, lateral distortion and lateral resolution of the measurement are discussed. Detection, specification and calibration methods of fabrication errors of the CGH-null are analyzed with respect to the fabrication technology of the CGH. For a high accuracy CGH-null test of an asphere, the errors of the CGH must be negligible or well calibrated. Techniques to calibrate the systematic error of the test setup are presented with examples. Experimental results of interferometric CGH-null tests of an asphere are presented.

A simple laser interferometer is proposed. It consists of a small concave mirror, a gas laser, a semitransparent flat mirror, a concave ellipsoidal mirror under test, and a register equipment. Laser beam is reflected by very small concave or convex paraboloidal mirror and then it is directed to the semitransparent flat mirror, and to the mirror under test. The light reflected by the flat mirror is reference wave, the light reflected by the mirror under test is imperfect wave to screen or in a register equipment to obtain useful interferogramms. It is possible to test any concave ellipsoidal mirror by manufactured and tested at Crimean Astrophysuical Observatory.

A new experiment system of three-dimensional shape measurement is presented. The advantages and the disadvantages are analyzed. In this experiment system, using digital light projector replaces traditional mode of projecting, and electronical grating replaces traditional grating. Obviously, the system has many advantages such as higher precise, easier to realize, etc. But there still are some disadvantages because of the characteristic of the system. We create different direction electronical gratings with different period in the system and use the four-step phase-measuring profilometry to get the phase and height of the detected object. According the experiment result, we analyze the errors introduced by the system. Then decrease such errors as much as possible. From the last result, we can conclude that the system has high practical value.

Paper presents results of in vivo measurements of dynamic variations of the corneal topography by use of the Twyman Green interferometer. Sequence of interferograms were recorded by the CCD camera and stored in the computer memory. Then the fringe tracking method was used separately to each interferogram giving the phase surface of the wave reflected from the cornea in the numerical form. Results from neighboring interferograms were subtracted giving new sequence of changes of the corneal topography within 40 ms. Obtained results show the complex space distribution of the corneal topography variations.

A prototype of a system for in-process monitoring of material removal in fluid jet polishing (FJP) is presented. The measurements make use of temporal phase unwrapping (TPU) allowing for a large working range. The measurement system will be discussed, with all problems that had to be overcome like water on the surface and vibrations, as well as the FJP system. The basics behind TPU will be presented and the first results will be shown. Finally, the capabilities of the system will be discussed. The presented system enables the in-process monitoring of the footprint as obtained by the FJP technique and measurement of the material removal rate.

To measure the straightness and parallelism error of high precise and the overlong guides (or so 1500m) is different to measure the common guides. We apply principle of the optical collimation to measure the straightness error of the subsection guide in turn from the one end with laser collimation instrument. This way calls separate method. After measuring the straightness error of one of the datum guides, we measure the parallelism error of the guides. This way calls objective method. We can assess the straightness and parallelism error by adopting illustrate or numeration to compile procedure to deal with data and draw the curve of error.

Laser holographic interferometer was used for visualization of axisymmetrical free flows at Mach number 6 in test section of the hypersonic wind tunnel. This interferometer was designed on a basis of Schlieren apparatus with restricted test beam diameter. So the visualization of all flow fields including its boundaries was impossible. Such visualization, however, is necessary for the calculation of radial density distributions from the interferometric data. It is of interest to study the density behavior near axis, where under theoretical prediction a local uniformity can exist. The interferometric measurements assure determination of flow core boundaries and ratios of nozzle exit pressure to the pressure in test section. It is proposed to do density fields simulation based on results of the theoretical calculation of jets at established pressure ratios. In addition, special simulation is used for description of the density uniformity near the axis. Using simulated density fields, theoretical interferograms were calculated using digital interferometry technique, which was developed by authors early. So it was defined the condition for revealing local perturbation of flow field near axis.

The paper presents experimental investigation on generation and observation of bulk strain solitary waves in plexiglas. The thorough analysis of the available data on elastic characteristics of plexiglas and recalculation of the elastic moduli of the third order allowed to conclude that bulk compression solitons can exist in this material. It was then proved experimentally via recording of such waves both in the homogeneous wave guide and in finite wave guides with different end conditions (wave reflection from a clamped and free end of the wave guide). The results obtained are compared with previous data on soliton generation in polystyrene.

Electronic Speckle Pattern Interferometry (ESPI) is a well-known tool in cultural heritage diagnostics. It can also reveal cracks and debonding of tiles in ancient mosaics of roman and medieval age. This paper describes a portable electro-optic system (it integrates the ESPI and local speckle correlation techniques) as a diagnostic tool to evaluate the state of conservation of ancient mosaic. Some experiments are been carried out on real, ancient, mosaics in laboratory and in situ.