Surface measurement technology's growing demand for fast and highly accurate data processing and representation results from the need to automate measuring processes and to raise quality control requirements in production. Measuring micro and macro profiles as well as surface roughness in production-related areas is a task that increasingly faces industrial production. Optical and particularly interferometrical methods of micro and macro surface investigation are especially favorable by virtue of their ability to measure without physical contact and therefore nondestructively and with high speed.

Electronic speckle pattern interferometry (ESPI) is applied to 3-D deformation mapping in practical problems from constructional engineering. The shrinking behavior and bonding ability of repair mortars applied in the restoration of historical stone buildings is monitored. Strategies are illustrated to process the huge amount of deformation data toward parameters characteristic of the relevant processes. Thus, ESPI is extended to routine applications in industrial inspection.

The quality of smooth technical surfaces is characterized by the surface roughness and by surface defects. For a stable quality control, objective measuring conditions are necessary. The objective measurement of surface defects especially is an unsolved problem. For the investigation of the scattering characteristics of different surface defects, a measuring device was developed. With this measuring device, the type of defect and the angle dependent scattering intensity were measured and compared with theoretical calculations.

This paper describes an optical system, designed and realized by Officine Galileo, for contactless control of reflective and semireflective surfaces. LINESCAN optical system is based on dark field illumination, and it is able to detect scattered light from surface defects by means of a linear CCD array. A miniature composite prism combines the lighting and imaging channels, also providing dark field illumination and allowing access into very small cavities. LINESCAN is capable of detecting scratches, digs, rust stains and other similar defects, characterized by thickness greater than 10 microns, on spherical and toroidal surfaces. The system provides a fast restoration of the bidimensional surface defects image from a discrete set of mondimensional images. A stepping motor driven by a computer rotates the object. A typical industrial application of LINESCAN is the inspection of inner and outer ring races of ball bearings. LINESCAN allows substantial time saving in testing and assembling ball bearings.

A real-time quality inspection system for textile industries in currently being developed on a parallel multitransputer architecture. The objective of this work is a realtime quality assurance system, able to inspect textiles based on machine vision and to automatilly validate their quality level. Parallel processing is employed, and defect recognition algorithms enabling parallel execution have been developed in order to meet time constraints imposed on line quality inspection systems for textile industries.

The flexibility of computer-generated holograms (CGII) means a great potential of applications. Generally, the CGH does not just replace another component. It is developped as a part of an optical system, and the resultant system looks different from a solution relying on classical components alone. The main advantage of a CGH stems from its functions and combinations of them which other components cannot provide. Well-known functions are the beam splitting capability, wave front shaping and transformation, storage, and generation of 3D light distributions. All of these functions are supported by the waves which are generated in the optical reconstruction step.

A novel optical system is described which can be used to change the intensity profile of a laser beam without the increase in beam divergence which results from conventional techniques. The technique uses a telescope, the first lens of which is designed to introduce an amount of spherical aberration. This changes the intensity distribution of the beam in the focal region where a second lend is located. The second element removes the aberration and collimates the beam. Cylindrical lenses can be used to independently shape the intensity profile of the beam in the two azimuths.

Scattering and absorption phenomena in translucent materials are usually studied by spectroreflectometric measurements, but can also successfully be investigated by employing a color monitor for translucent materials (CTM). A CTM is a fiber optical instrument which separately detects light which traveled short (L_c) and long distances (L_e) in the material under consideration. In this study, the authors qualitatively interpret experimental results by using a Monte Carlo simulation of photon pathways in the material. In this simulation, photons are assumed to be absorbed along the ray path between two scattering events. Scattering is simulated by changes in the photon direction, taking into account the exact phase function for scattering on spherical particles. The boundary conditions imposed are analogous to the experimental situation. Results are presented as the radial distribution of reflected photons, i.e., photons emerging at the plane of incidence. In order to transfer the simulation results to the experimental situation with several more or less randomly oriented fibers, the fiber distribution in the measuring head of the CTM has been characterized by automated image analysis. This fiber distribution has been used to calculate a specific transfer function which enables a theoretical prediction of CTM measurements. Experimental results with monodisperse latex suspensions as well as the model simulations demonstrate the existence of an optimum in the detected L_e signal at a specific concentration of the suspension. Discrepancies, however, exist between the experimentally determined and simulated location of the optimum. The simulation model furthermore predicts a highly increasing sensitivity to absorption with increasing suspension concentration. It is concluded that Monte Carlo simulation can be a valuable tool for predicting fiber optical measurements of reflection and absorption phenomena in bulk translucent materials, at least for the L_c signal.

Every mirror reflectance can be increased by deposition of a two-material multilayer, consisting of alternating transparent layers and layers of any arbitrary material. So one may use any metal or 'bad' absorbing dielectrics as a component of high-reflective multilayer mirrors. The purpose of this report is to prove a possibility of making multilayer mirrors consisting of alternating transparent and absorbing layers without any restriction of absorbing material permittivity.

The estimation of performance of computer-generated optical elements (CGOE) at the design stage is the actual task. In this paper the mathematical model of laser beam focusing by CGOE is suggested. On the basis of this model, the following results have been obtained: a numerical method for the diffraction computing of the field at the focal region, and also algorithms and software for investigating diffraction characteristics of focusators within the scope of computer simulation. The estimations of power efficiency, focal line width, and light intensity distribution at a focal region for various types of focusators vs physical parameters, number of samples, and number of quantization levels are obtained as a result of computational experiments. CGOE with an elevated depth of focus and focusator at semi-ring are investigated.

The accessibility of the optical information inside the Airy disk is experimentally proved. A 3- D image of a 0.1 micrometers slit was obtained with an Airyscan microscope at (lambda) equals 0.63 micrometers .

A new method is investigated for synthesis of computer-generated optical elements to focusate the radial-symmetrical laser beam into the complex focal contours--in particular, into the alphabetical-digital symbols. The method is based on decomposition of the focal contour by segments of the straight lines and half-circumferences, following corresponding spacing out of the focusator on elementary segments with a ring shape and solution of the inverse task of focusing from focusator segments into corresponding element of the focal contour. It was determined in the computer experiment that the theoretical efficiency of synthesized focusators into the letters is above 85%.

The possibilities of controlling production processes and products by means of optical filter devices are largely determined by the quality of the filters used. The basic requirement for infrared filters designed for selecting radiation of heat sources is that they be high contrast. A promising method providing a simple and reliable constructive solution of this problem is the combining of interference systems, consisting of a small number of layers and forming a transmission band in the filter transmission region, with a scattering system effectively attenuating the background radiation in a wide spectral region.

An overlapping optical field (OOF) technique is developed to transform an optical field of Gaussian intensity into one with one-dimensional uniform intensity. The theoretical analysis and detected results demonstrate that one-dimensional uniform optical field with efficient utilization of optical energy can be obtained using the OOF technique. An experimental system for realizing the OOF principle is given, and the experimental results about the particle sizing and velocimetry are shown.

In the aircraft industry, rigorous testing of dynamic seals for hydraulic actuators is necessary. There is a requirement to test the seals inside the actuators. The difficulties posed by this requirement to remotely sense and acquire the images of the dynamic seal can be reduced by the use of fiber optics. The fiber optics transmits the images of the seal inside the actuator to the camera. The various schemes using fiber optics for this purpose have been presented. The images were digitized using a computer vision system. By using different traditional image enhancement techniques, the acquired images were analyzed and varying results presented. Some of the results enabled surface imperfection such as edge cracks to be identified, with the images of other edge deformation of the seal sharpened and easily interpreted.

A mathematical procedure is described for identifying the modes, or nondiffracting beams, of (alpha) -power GRIN. The general procedure is used to find two novel analytical solutions, which contain as particular cases previously known modes.

A new family of zone plate is described that have angular phase detours for creating zero axial irradiance. This kind of diffractive optical element may be useful in optical alignment.

Two methods are described for shaping the irradiance distribution along the optical axis by the use of apodized polar curves as spatial filters.

Apodized holographic gratings and dielectric mirrors have been designed, fabricated, and tested as outcoupling components of unstable CO₂-laser resonators. The influence of the imaging properties of profiled dielectric layers on the laser field has been investigated.

The dynamic model of a deformable adaptive mirror with actuators is presented. This model takes into account both properties of the deformable mirror itself and dynamic properties of each individual actuator. The set of equations describing dynamic behavior of such a complex system was derived. The approximate solution of this set was obtained by modal decomposition over the set of free deformable mirror spatial eigenfunctions. It was found that spatial mode frequency spectrum of dynamic system 'deformable mirror-actuators' is distorted with respect to the case of the free deformable mirror. Mode frequency dependence for each individual mode from the actuator's parameters was calculated. It was shown that the fundamental system frequency poses the largest frequency shift. The authors have also established the connection between some optical quality criteria (RMS wavefront deviation, aberration criterion etc.) and obtained modal decomposition. The control system for the adaptive deformable mirror was designed by treating the deformable mirror-actuators dynamic system as a multidimensional multicoupled automatic control system. It was shown it is possible to get a noticeable improvement in system dynamic behavior. The proposed dynamic model and its connection with optical quality criteria for a deformable mirror-actuator system can be used for adaptive optics systems design.

This paper reviews the optical, temporal, and contrast properties of the spatial light modulator (SLM) photoconductivity organic polymerliquid crystal (POP-LC) type at the writing by nanosecond light pulses ((Tau) equals 10ns, (lambda) equals 0,53 micrometers ). The modulation effects on LC caused by the birefringence, the holesteric-nematic phase transition, and the dynamic scattering were used. Clear apertures of POP-LC modulators were (phi) equals 25 mm or (phi) equals 110 mm.

A new method of phase synthesis of metrological holographic gratings in high-quality adaptive interferometer by sequential multiplication on the photographic plate of an interference field is discussed.

All-sky cameras with field-of-view (FOV) of 180 degree(s) are used in several astronomical and terrestrial applications. In its simplest form, such a camera consists of a simple photographic camera which photographs the image of the sky reflected in a spherical mirror. This design is attractive due to its comparatively low cost, as the spherical mirror has very relaxed tolerances on surface shape and accuracy. However, the image such a camera produces suffers from angular distortion near the edge of the image. If, instead of a spherical mirror, an aspherical one is used, it is possible to eliminate angular distortion and to obtain constant angular magnification over the whole 180 degree(s) FOV. The derivation of the differential equation of the required aspherical surface is outlined, and the results of numerical integration of the equation are described.

Utilizing the unique properties of holography, it becomes possible to synthesize interference fields to produced large-aperture holographic optical elements such as holographic lenses and holographic diffraction gratings. It is on the synthesis of the large-aperture interference fields that the authors focus attention. To achieve the practical fulfillment of interference field synthesis, it has been necessary to develop a series of entirely new optical methods, which are discussed in this paper.

We initially study a peak of the photorefractive two-wave mixing gain which appears for a particular frequency of a sinusoidal applied electric field. The optimization of the process by applying periodic pulsed electric fields leads to a considerable rise of the two-wave mixing gain. The authors demonstrate that the gain reached with this technique is higher than the maximum gain obtained with usual enhancement techniques. Effectively, with a Bi₁₂GeO₂₀:Fe sample, a gain of 10 cm^-1 is obtained, compared to 2 cm-1 in the same crystal with the other techniques.

Four-wave mixing in nematic liquid crystals differs from that in a different medium, such as atomic vapors or isotropic materials. In a nematic liquid crystals (NLC), wave mixing is due to spatial holograms constructed by the four interacting waves. Using the holographic approach, the authors have recorded diffractive index gratings in the NLCs. A theoretical study of nonlinear optical effects in NLCs, including degenerate four-wave mixing, is presented. Also presented are a description of the degenerate four-wave mixing optical geometry used and results obtained from the reconstruction of images.

The process of Brillouin amplification when the input pump and signal beams have Gaussian spatial profiles is investigated. Two distinct regimes are considered. In the small signal regime, it is shown that the signal beam undergoes spatial beam narrowing as it propagates through the amplifier owing to the exponential dependence of signal beam gain on pump beam intensity. The relative change in spot size is found to depend on both the peak signal intensity gain and on the input signal to pump spot size ratio. In the large signal (depleted pump) regime, it is found that the signal beam becomes broadened if the pump depletion is significant and the output spot size depends on the input signal beam intensity. The theoretical predictions are verified experimentally using a Q-switched Nd-YAG laser to provide pulses of 30 ns FWHM duration and wavelength 1.06 micrometers , and using CCl₂FCCIF₂ as the nonlinear medium.

The influence of bandwidth (2-800 GHz) and beam quality (2-70 X diffraction limit) on stimulated brillouin scattering (SBS), and consequently on phase conjugate reflectivity, threshold, and fidelity, have been investigated. Efficient stimulated scattering of broad-band poor beam quality radiation has been demonstrated. Broadband poor beam quality results show fair quantitative agreement with narrow-band good beam quality results, when scaling laws based on spot size, intensity, coherence length, and Rayleigh range are used. The influences of different SBS media and geometry are reported, predominantly at the XeCl laser wavelength of 308 nm, where phase conjugate cavities not requiring line narrowing are of great practical interest. The response time of the SBS process is investigated. Observations of response times much faster than the decay time of the acoustic wave in the medium are presented, demonstrating the potential of SBS for conjugating beams which display rapid (< 1 ns) spatial variations, such as those imposed on beams originating from discharge excited lasers. Experimental observations of the effect on SBS response of laser intensity are presented and interpreted with the aid of a semi-analytical expression which allows scaling to slower time- scales, longer pulses, and longer wavelengths.

A detailed experiment on phase conjugation via degenerate four-wave mixing in LiF:F₂^- and NaF (F₂⁺)^* crystals pumped by pulse-periodic Nd:YAG laser is described. The dependence of the efficiency of phaser conjugation on the energies and polarizations of the interacting beams and on the concentration of F₂^- CC is described. The mechanism of phase conjugation is connected with the saturation of the absorption in the color center crystals. Phase conjugation was investigated in LiF:F₂^- crystals that worked simultaneously as a passive Q-switch of a Nd:YAG laser. This allows use of the LiF:F₂^- crystal as a phase conjugated mirror of a Nd:YAG laser.

The main characteristics of a compact phase conjugate resonator TEA CO₂ laser as a function of the cw pump power are reported. Nonlinear dependence of the output peak-power has been measured, and the existence of an optimum pump power value has been demonstrated. Output peak-powers in excess of 40 kW have been reproducibly obtained for 5 W cw pump power. Heterodyne measurements have shown that a Fourier-limited high-power pulse can be generated.

In parallel optical information processing systems, three important specifications have to be fulfilled: (1) high space bandwidth product, (2) amplification for signal restoring, and (3) compensation for aberrations. The authors present a coherent optical feedback system which is capable of processing a large number of channels entirely in parallel. The system consists of a ring-resonator with a phase-conjugating mirror (PCM), formed by a BaTiO₃-crystal, as an image amplifier. The aberration compensating property of optical phase-conjugation makes it possible to realize a feedback system with a space-bandwidth product up to >10⁵, which would hardly be achievable otherwise. In addition, PCM-devices can be also used for the realization of different operations, such as phase visualization, coupling of channels, and image storage.

A MOPA Nd:YAG laser source incorporating a SBS phase-conjugate mirror delivering 12 ns long 1,6X diffraction-limited pulses at a pumping rate of 10 Hz is experimentally demonstrated. High reflectivity (70-80%) of phase conjugate mirrors using CCIF₃ gas near its critical point and CH₄ gas with single laser shots is reported. Fidelity of phase conjugation stays high (0.8) with broadband radiation (0.7 cm^-1). Output MOPA energies and beam quality are measured as a function of oscillator output energy and amplifier flashlamp pumping level. Advanced beam steering performed with this phase-conjugate laser design is presented.

A number of important applications of high precision positioning actuator are related with laser technique and technology, optics, especially with large optical devices for the ground and space based astronomy. These actuators can be used in adaptive optics as the displacement and force actuators to preform in real time a mirror surface, conjugated with the wave front aberration by means of elastic deformation of mirror substratum [1,2]. A spring—type magnetostrictive actuator (STMA) in which Wiedemann effect (WE) [4] is realized, was described in [3] - is one of the interesting types of macro actuators, by means of which it is possible to achieve a precision displacement level 200 Lm with the accuracy of positioning up to 0.1 Lm in a real time scale ( up to 5 ms). Hence, the STMA satisfies all the visible and infrared adaptive optics requirements. A more complete understanding of such approach to actuators creation allows one to establish the main distinguished STMA features [5,6] : 1. High level of STMA relative longitudinal defomatins is controlled by STMA designed parameters and reaches 10 -10 when using ordinary magnetostrictive materials. This level of relative longitudinal deformations is accessible only for best sorts of piezoceramics; 2. A width of STMA magneto mechanical resonant frequencies band (from 10 Hz up to 1 kHz) is controlled by designed STMA parameters; 3. It is possible to use the inverse Wiedemann effect (IWE) for STMA material stresses controlling and, consequently, for closed loop STMA control.

The method of compensation for the angular dispersion of phase-matching is developed theoretically and experimentally for a collinear but basically nonmonochromatic pump radiation. According to this method the converter's sensibility to nonmonochromatic radiation is lowered considerably. The method is based on a preliminary modification of the pump beam by passing it through a medium with an angular dispersion close to the phase-matching dispersion. When this compensation method is used, the intensity of the second harmonic can be increased by an order of magnitude or more. Illustrative numerical calculation are made for KDP and LiIO₃ crystals. It is shown that the method can suppress successfully the influence of fluctuations of the pump frequency on the second-harmonic intensity. The method was tested experimentally by generation the second harmonic of neodymium laser radiation (spectral width 8 nm) by OO-E interaction. An increase in the integrated intensity of the second harmonic by an order of magnitude was achieved.

This paper presents the principles of the use of B- and Fibonacci-transformations of optical images for the information conformity of the processes of their forming and perception.

Graduating rules used as length etalons in optical measuring instruments and tools need to be checked for graduation accuracy. The best way to perform this is by using a laser interferometer as a linear displacement transducer, some specially designed optoelectronic interfaces, and a computer for control and data processing. Implementation of measuring equipment consisting of these assemblies is described below.

Unsaturated fatty acids arachidonicurn and elaidicwn acids with liquid crystal Sit properties were investigated. These aci4s have an important role in biologicel membrane.The electrical meastie' rements showed nonlinear dielectrical properties and ferroelectri.city.Optical nonlinear behaviour, dependent on temperature, distan— ce, cell thickness, incidence angle and incident optical laser po.•wer was aimlised.Phe samplçs Were ittilised like nonlinear lens and in an all—optical bistable device.

This paper is devoted to the analysis of methodical error induced by the curvature of spiral of Archimedes used in some electro-optical measuring devices for point source image coordinate determination. Methods of mathematical processing of the measurement results (corrections) based on definition of device parameters depending both on design characteristics and instrumental errors are described. The measurement results verifying considerable accuracy enhancement owing to mathematical correction methods implementation are presented.

The free-electron laser (FEL) amplification mechanism is discussed in this paper, including the influence of electron beam quality (energy spread, emittance, stability) on FEL performance. Considerations regarding the choice of the electron accelerator are presented, and some characteristic properties of laser radiation are discussed. An overview of FEL- facilities for the infrared spectral region, which are being designed and built worldwide, is given.

The objective of this paper is to motivate a new class ofdigital logic. OptiComp has focused on a digital optical logic family in order to capitalize on theinherent benefits of optical computing which include: Attribute #1: High FAN-IN and FAN-OUT Attribute #2: Low power consumption Attribute #3: High noise margin Attribute #4: High algorithmic efficiency using "Smart" interconnects Attribute #5: Free space leverage of GIBP (gate interconnect bandwidth product) Other well known secondary advantages of optical logic include (but are not limited to): Zero capacitive loading of signals at a detector Zero cross-talk between signals Zero signal dispersion Minimal clock skew (a few picoseconds or less in an imaging system) The primary focus ofthispaper wiibe to demonstrate how each ofthe five advantages can be used toleverage other logic family performance such as GaAs; the secondary attributes will be discussed only in the context of introducing the DOC III architecture.