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Despite therapid and continuous progress in the constructionofvehicles and accompanying improving road infrastructure,the road safety issue remains very serious. Especially, it concerns intersections and road junctions where nearly 30% of road accidents take place. The paper is focused on a newintelligent path displaying support system to be installed on intersections of complex geometry combined with multiphase traffic lights. It consists ofoptical projectionof two different horizontal signs,i.e. strips designating lanes for the green-light directions and perpendicular blocking lines for the red-light directions.

W artykule przedstawione zostały procedury pomiarowe wybranych parametrów optycznych endoskopów wykorzystywanych w zabiegach diagnostyczno-leczniczych. Procedury te zostały opracowane przez Instytut Fizjologii i Patologii Słuchu (IFPS) oraz Instytut Optyki Stosowanej (INOS) na podstawie doświadczeń medycznych oraz wiedzy z zakresu optyki instrumentalnej. Badane były między innymi: równomierność oświetlenia obiektu przez układ optyczny endoskopu oraz jego wpływ na rejestrowany obraz, rozdzielczość rejestrowanego obrazu, wartość transmisji układu oświetlającego i rejestrującego, głębia ostrości oraz dystorsja układu. Parametry te mają znaczący wpływ na jakość odwzorowania obrazu, a tym samym na ocenę przez lekarza zmian chorobowych u pacjenta.

The paper presents an alternative technique of calculation the retardance of quartz waveplates. The technique utilizes continuously tuned wavelength, which identifies the zero-order fringe and simultaneously facilitates high repeatability of the optical path difference across the entire visible spectrum. Unlike in classical method, precise monitoring of the current increase or decrease of the interference order is not required. The discussion includes comparison of the standard deviation between the classical and novel approaches. Full Text: PDF References M. Pluta, Advanced Light Microscopy (Vol. 3, PWN, Elsevier, Warszawa-Amsterdam-London-New York-Tokyo, 1993). DirectLink M. Pluta, "Object-adapted variable-wavelength interferometry. I. Theoretical basis", Journal of Opt. Soc. Am., A4(11), 2107 (1987). CrossRef M. Pluta, "Variable wavelength microinterferometry of textile fibres", J. Microscopy, 149(2), 97 (1988). CrossRef M. Pluta, "On double‐refracting microinterferometers which suffer from a variable interfringe spacing across the image plane", Journal of Microscopy, 145(2), 191 (1987). CrossRef M. Pluta, "Variable wavelength interferometry of birefringent retarders", Opt. Laser Technology, 19(3), 131 (1987). CrossRef D. Litwin, A. M. Sadik, "Computer-aided variable wavelength Fourier transform polarizing microscopy of birefringent fibers", Optica Applicata 28(2), 139 (1998). DirectLink A. Sadik, W. A. Ramadan, D. Litwin, "Variable incidence angle method combined with Pluta polarizing interference microscope for refractive index and thickness measurement of single-medium fibres", Measurement Science and Technology, IOP Publishing 14(10), 1753 (2003). CrossRef J. Galas, S. Sitarek; D. Litwin; M. Daszkiewicz, "Fringe image analysis for variable wavelength interferometry", Proc. SPIE 10445, 1044504 (2017). CrossRef D. Litwin, J. Galas, N. Blocki, "Automated variable wavelength interferometry in reflected light mode", Proc.SPIE 6188, 61880F (2006). CrossRef J. Galas, D. Litwin, M. Daszkiewicz, "New approach for identifying the zero-order fringe in variable wavelength interferometry", Proc. SPIE 10142, 101421R (2016). CrossRef D. Litwin, J. Galas, M. Daszkiewicz, T. Kryszczynski, A. Czyzewski, K. Radziak, "Dedicated optical systems of the Institute of Applied Optics", Phot. Lett. Pol., vol. 11, no. 2, pp. 29-31, (2019). CrossRef D. Litwin, K. Radziak, J. Galas "A fast variable wavelength interferometer", Proc. SPIE 11581, 115810O, (2020). CrossRef

The paper focuses on two families of instruments that have been developed over several years in the Institute of applied Optics using microinterferometric and confocal approach. The continuously variable light source constitutes the binding element of these two classes of measuring devices. The light source has to emit continuous spectrum. During measurements the selected wavelength must be determined with significant accuracy, which constitutes the key and critical factor of the measurement process as a whole. The described systems are only a small part of what photonics offers but are very useful in characterizing many objects and materials in research and industrial environment.

Revolutionary progress in the photonic technology provides the ability to develop military systems of new properties not possible to obtain with the use of classical technologies. In recent years, this progress has resulted in developing advanced, complex, multifunctional and relatively cheap Photonic Integrated Circuits (PIC) or Hybrid Photonics Circuits (HPC) built of a collection of standardized optical, optoelectronic and photonic components. This idea is similar to the technology of Electronic Integrated Circuits, which has revolutionized the microelectronic market. The novel approach to photonic technology is now revolutionizing the photonics’ market. It simplifies the photonics technology and enables creation of technological centers for designing, development and production of advanced optical and photonic systems in the EU and other countries. This paper presents some selected photonic technologies and their impact on such defense systems like radars, radiolocation, telecommunication, and radio-communication systems.

The paper describes a mobile application to be used in a chemical analytical laboratory. The program running under the control of Android operating system allows for preview of measurements recorded by the emission spectrometer. Another part of the application monitors operational and configuration parameters of the device in real time. The first part of this paper includes an overview of the atomic spectrometry. The second part contains a description of the application and its further potential development direction.

The phenomenon of laser light scattering provides the technology for visualization and testing the inner structure and homogeneity of materials. Some of them excited by the laser light in the tomographic process can emit light the wavelength of which is different than that of excitation laser. Such photoluminescence can be a source of additional information of the material’s structure. Combining the Laser Scattering Tomography (LST) and Spectrometry techniques has enabled us to develop a new type of an LST technique. The system is useful for investigations of various materials like semiconductors (Si, GaAs) ceramics, crystals for passive absorbers for high power pulse lasers, and laser crystals.

The paper presents a relatively simple though effective approach to fringe field processing for variable wavelengthinterferometry- related techniques including a detailed analysis of noise influence on the accuracy of fringe parameters extraction.

The paper presents a collection of selected optical systems recently developed in the Institute of Applied Optics-INOS. The collection includes the family of techniques where the continuously modified wavelength facilitates high accuracy measurements of optical and geometrical features of the object in question i.e. the variable wavelength interferometry and confocal chromatic sensors. In addition, the paper refers to the construction of a new type of a spectrometer with rotating plasma and an illumination system supporting the road safety. Full Text: PDF References M. Pluta, Advanced Light Microscopy (Vol. 3, PWN, Elsevier, Warszawa-Amsterdam-London-New York-Tokyo, 1993). DirectLink M. Pluta, "Object-adapted variable-wavelength interferometry. I. Theoretical basis", Journal of Opt. Soc. Am., A4(11), 2107 (1987). CrossRef M. Pluta, "Variable wavelength microinterferometry of textile fibres", J. Microscopy, 149(2), 97 (1988). CrossRef M. Pluta, "On double‐refracting microinterferometers which suffer from a variable interfringe spacing across the image plane", Journal of Microscopy, 145(2), 191 (1987). CrossRef K. A. El-Farahaty, A. M. Sadik, A. M. Hezma, "Study of Optical and Structure Properties of Polyester (PET) and Copolyester (PETG) Fibers by Interferometry", International Journal of Polymeric Materials 56(7),715 (2007). CrossRef J. Galas, D. Litwin, M. Daszkiewicz, "New approach for identifying the zero-order fringe in variable wavelength interferometry", Proc. SPIE 10142, 101421R (2016). CrossRef A. Sadik, W. A. Ramadan, D. Litwin, "Variable incidence angle method combined with Pluta polarizing interference microscope for refractive index and thickness measurement of single-medium fibres", Measurement Science and Technology, IOP Publishing 14(10), 1753 (2003). CrossRef J. Galas, S. Sitarek; D. Litwin; M. Daszkiewicz, "Fringe image analysis for variable wavelength interferometry", Proc. SPIE 10445, 1044504 (2017). CrossRef D. Litwin, A. M. Sadik, "Computer-aided variable wavelength Fourier transform polarizing microscopy of birefringent fibers.", Optica Applicata 28(2), 139 (1998). DirectLink D. Litwin, J. Galas, N. Blocki, "Automated variable wavelength interferometry in reflected light mode", Proc.SPIE 6188, 61880F (2006). CrossRef M. Pluta, "Variable wavelength interferometry of birefringent retarders", Opt. Laser Technology, 19(3), 131 (1987). CrossRef K. Fladischer et al. "An ellipsoidal mirror for focusing neutral atomic and molecular beams", New journal of Physics, 12(3) 033018 (2010). CrossRef K. Fladischer et al. "An optical profilometer for characterizing complex surfaces under high vacuum conditions", Precision engineering Elsevier 32(3), 182 (2008). CrossRef A.E. Weeks et al. "Accurate surface profilometry of ultrathin wafers", Semiconductor Science and Technology", IOP Publishing, 22(9), 997 (2007). CrossRef D. Litwin et al. "Overview of the measuring systems where a continuously altered light source plays a key role: Part I", Proc. SPIE 10808, 10 8080B (2018). CrossRef D. Litwin et al. "Noise reduction in an optical emission spectrometer with rotating diffraction grating", Proc. SPIE 10142 101421Q (2016). CrossRef D. Litwin et al. "Photonics approach to traffic signs", Proc SPIE 10142 1014214, (2016). CrossRef

The paper concerns the development of an optical emission spectrometer with a helium microwave rotating plasma as the excitation source which is an alternative to ICP spectrometers. In the new solution helium is used as the plasma and carrier gases, which helps to determine elements such as halogens and some non-metals. The new system should demonstrate decreased operating costs i.e. the flow of 1L He/min compared to about 15L Ar/min for ICP. Its spectral range is within 165 nm - 840 nm, sensitivity at the level of ppb and spectral resolution is equal to 0.01 nm. The system uses a set of two photomultipliers for VIS and UV regions. The entire spectrum is collected during a single rotation of the diffraction gratings. The paper describes the collection of algorithms developed to decrease noise and smooth spectral data.

The family of VAWI techniques (for transmitted and reflected light) is especially efficient for characterizing objects, when in the interference system the optical path difference exceeds a few wavelengths. The classical approach that consists in measuring the deflection of interference fringes fails because of strong edge effects. Broken continuity of interference fringes prevents from correct identification of the zero order fringe, which leads to significant errors. The family of these methods has been proposed originally by Professor Pluta in the 1980s but that time image processing facilities and computers were hardly available. Automated devices unfold a completely new approach to the classical measurement procedures. The Institute team has taken that new opportunity and transformed the technique into fully automated measurement devices offering commercial readiness of industry-grade quality. The method itself has been modified and new solutions and algorithms simultaneously have extended the field of application. This has concerned both construction aspects of the systems and software development in context of creating computerized instruments. The VAWI collection of instruments constitutes now the core of the Institute commercial offer. It is now practically applicable in industrial environment for measuring textile and optical fibers, strips of thin films, testing of wave plates and nonlinear affects in different materials. This paper describes new algorithms for identifying the zero order fringe, which increases the performance of the system as a whole and presents some examples of measurements of optical elements.

On the basis of thermally bonded Er,Yb:glass/Co:MALO microchip a laser head pumped by fiber coupled laser diode was designed. The performance of the laser head were investigated and the main output parameters were determined. The energy over 40 μJ in 3.8 ns pulse with repetition rate of 0.735 kHz was achieved. The laser head characterized by such parameters can successfully be used in tele-detection applications.

This paper presents the Variable Wavelength Interferometry (VAWI) technique, its applications and expected research potential of this system equipped with a femtosecond laser. The system is configured for observation and measurement of local optical parameters modified by a high power laser pulse. The VAWI measurement technique has a unique feature that can visualize and enables investigation of the immediate matter response to a single high power laser pulse just in the pulse area, which can locally modify dielectric and optical parameters of matter along the propagation path. It affects the dielectric tensor, refractive indices and it may induce birefringence. The high power laser pulse is responsible for the nonlinear effects in the optical materials like crystals, photonic crystals, optical fibers etc. The VAWI provides the ability to measure very accurately the above optical parameters along the laser pulse propagation path and neighboring regions in the VIS-NIR spectral ranges.

This article presents the principles of selection of colours and the thickness of lines during designing of traffic signs, the legal aspects traffic signs must correspond to, test methods used during assessment of both roadway markings and vertical experimental traffic signs, results of studies of those signs and their assessment in the case of possible changes in drivers behaviour.

An extended interferometric method is suggested to increase the measuring accuracy of the spectral dispersion curves of weakly oriented polymeric objects. This extended method is based on the variable-wavelength interferometry fringe field interference (VAWIFFI). Using this method, the calculation of the initial interference order is more accurate, and it can be determined over a small range of the visible spectrum. The advantage of the extended VAWIFFI method is that it is not necessary to take a certain reference like the zero order fringe and/or the initial coincident configuration. In comparison to the single- and multi-fringe VAWIOFT and Pluta methods, the measurement accuracy of the extended VAWIFFI method is discussed.

The requirements for high precision metrology devices have increased rapidly in recent years. Furthermore, the applications are spreading to many new branches of science and technology. Hence new demands are appearing which are related not only to classical parameters such as precision and speed but also to other factors including the environment in which the measurements must be performed. In this paper we present a new device for measuring complex surface profiles of samples held under high vacuum conditions. The surface profile is obtained by scanning an optical sensor, held in air, across a standard view-port. The sensor has a lateral resolution of 25 μm and a perpendicular distance resolution of 0.12 μm over a range of 3 mm. The maximum scanning area is a circle, 30 mm in diameter. The device was developed to characterize silicon wafers for use as mirrors for atom optical applications. The mirrors are formed by bending the silicon under an applied electric field, which requires high vacuum conditions to prevent arc discharge. In the last part of the paper we discuss how simulations can be used to determine the required sampling grid spacing for obtaining the surface profile shape with a given accuracy.

Geometric characterization of 50 mm diameter, 50 µm thick single-crystal Si(1 1 1) wafers has been performed using complementary methods: industry-standard capacitance measurements of warp and total thickness variation (TTV), and a technique we term scanned chromatic confocal profilometry (SCCP). We compare the measurements made by the two techniques and demonstrate the limitations of capacitance measurements when applied to ultrathin wafers. The two-dimensional SCCP measurements are shown to enhance the description of wafer thickness variations beyond that generated by the standard test method. We discuss a Fourier transform-based analysis and show it to be useful in wafer quality assessment. Adding a summary of spatial frequencies in a wafer's thickness map to the conventional measures of warp and TTV provides a more complete summary of the salient features of a wafer's geometry.

The aim of the research was to investigate experimentally the process of dust lifting from a layer. The delay in lifting the dust from the layer behind the propagating shock wave and the vertical velocity of the dust cloud were calculated from the dust concentration measurements. Quantitative relations between those measurements and the parameters of the gas flow are presented. The results were compared with those obtained from the analysis of the frame pictures of the process. The pictures were made by using a high-speed camera working together with a Schlieren system. The measurements of the dust concentration behind the propagating shock wave are presented and analysed. The research was carried out for two selected dusts: black coal dust and silicon dust, and for different initial conditions: three shock wave velocities: 450, 490 and 518 m/s and three dust layer thickness equal to 0.1, 0.4 and 0.8 mm. Measurement results of the mean vertical component of dust cloud velocity between the layer and the first laser beam will be used in a new model, where the dust dispersing process is modelled as an injection of the dust from the layer. The dust concentration measurements will be very useful for validation of the model.

The paper demonstrates a simple technique for simultaneous determination of the directional refractive indices and the thickness of isotropic and anisotropic single-medium fibres. This technique is based on the variable incidence angle method combined with Pluta birefracting microinterferometry. A set of measurements of fringe deflections in the fibre image for light vibrating parallel to a fibre axis is performed at different incidence angles. A detailed procedure for the determination of the refractive indices and fibre thickness is given. The technique can be applied for thin film and fibres with irregular cross-sections.

The paper presents a 2D laser profilometer with the triangulation head. The system has been equipped with a robust algorithm for effective elimination of measurement artefacts typical for triangulation systems. The approach consists in multiple scanning of the object surface for various angular positions, followed by a process of fusion of these data images. The location of the rotation axis of the object has been calculated with the use of the specially developed calibration gauge which is crucial for a precise data assembling procedure. The paper covers the sequence of data processing, the design of the profilometer as a whole, system control and a collection of algorithms verified experimentally.

Overview of variable wavelength interferometric methods for measuring optical properties of cylindrical textile fibers precedes the latest approach based on the optical Fourier theory of birefringent fibers. Computer-Aided analysis of the optical Fourier transform pattern observed in a polarizing microscope is described as well as discussion of the results.

The paper is aimed at describing measurement methodology for characterizing quality of a silicon wafer applied as a focusing element in the Scanning Helium Microscope and continues the struggle against phenomena decreasing accuracy. The focusing mirror being the heart of the system and the decisive factor, which defines the resolution of the microscope, indicates the importance of testing methods. The systems made specially for this purpose provide the ability to create maps of the surface shape, thickness and surface roughness of the wafers. The paper shows many multidisciplinary issues associated with the measurements procedures and concludes with discussion on accuracy limits.

The paper provides new insights into Silicon wafer measurements in context of technological problems of developing a sophisticated measurement technique, which harnesses helium atom beam as a probe. Nano-resolution imaging techniques such as scanning tunnelling microscopy (STM) and atomic force microscopy (AFM) are well-know in surface science. A scanning helium atom microscope, where a focused beam of low energy, neutral helium atoms is used as an imaging probe is a new concept creating non-destructive and non-invasive surface investigation tool in science and industry. This paper is focused on measurements of flatness and thickness of the wafer, which is used as a deflecting mirror of the helium beam. Two -optics based- measurement techniques are presented: scanning confocal system and the Fizeau interferometer. The latter is applied as a quick reference device placed close to the production line whereas the former offers high accuracy flatness and thickness maps of the wafers.

The paper concentrates on the double-refracting systems - particularly variable wavelength techniques (VAWI) for reflected light... The family of techniques for (transmitted and reflected light) is especially recommended for studying objects, which produce optical path difference more than a few wavelengths. In such cases classical approach consisting in measuring deflection of interference fringes is not useful because of edge effects that break continuity of interference fringes. The VAWI methods have been invented in the time when image processing devices and computers were hardly available. Automated devices unfold a completely new approach to the classical measurement procedures. The paper discusses mainly construction aspects of the systems in context of the computerised instruments.

The ultra-thin 2 in. diameter silicon (1 1 1)-H(1 × 1) wafer appeared to be a promising material for a mirror focusing He-atom beam in a scanning atom microscope. To increase achievable at present resolution from 1.5 μm to a sub-micron range the 50 μm thick (1 1 1) silicon wafer with thickness distribution better than ±1 μm and 0.05° precision of miscut value is necessary. The purpose of this paper was to adapt X-ray measurements to control the miscut value with high precision for the 50 μm thick silicon wafers as well as to control the deviation of the wafer surface from ideal flat plane by measurements of low-angle reflection using X-ray high resolution diffractometer (HRXRD). The crucial point was the construction of a stress-free ultra-thin wafer holder. The precision of 0.01° miscut value was obtained. The deviation of the surface from the ideal flat surface obtained by X-ray measurements were compared with the one estimated from optical (confocal) method. A satisfactory good conformity between both methods has been observed.

A scanning helium atom microscope, is a very promising tool in surface science. In this technique a focused beam of low energy, neutral helium atoms is used as an imaging probe. The method is suitable to be applied to surface investigation in science and industry. The He-beam is created by supersonic expansion from a high pressure reservoir through a nozzle. It is focused onto the sample by a mirror created from an electrostatically deformed single silicon wafer. The shape of the mirror is obtained by an electrode system controlled by a computer. The focusing mirror consists of a chemically-prepared silicon wafer placed between two aluminium discs and suspended above an electrode structure. The surface quality of the mirror is the most crucial because it limits resolution of the helium microscope. Therefore it is planned to make various improvements to the mirror at both the macroscopic and atomic levels. The centre of gravity of the paper is in measurements of the surface quality of the wafer using scattered light based technique and AFM, so that the technological process of the wafers could be modified to obtain improved surface. The roughness was studied for the (111) oriented mechanically-chemically polished surfaces of silicon wafers with different miscut. The wafers with miscut of 0°, ± 0.25 o and ± 0.5 o toward (11bar2) direction were used for experiments. The miscut was determined with the accuracy of ±1'.

Nano-resolution imaging techniques such as scanning tunnelling microscopy (STM) and atomic force microscopy(AFM) are well-know in surface science. However, a scanning helium atom microscope, where a focused beam of low energy, neutral helium atoms is used as an imaging probe is a very new concept creating non-destructive and noninvasive surface investigation tool in science and industry. The He-beam is created by supersonic expansion from a high pressure reservoir through a nozzle. It is focused onto the sample by a mirror created from an electrostatically deformed single silicon wafer. The shape of the mirror is enforced by an electrode system controlled by a computer. The focusing mirror consists of a chemically-prepared silicon wafer placed between two aluminium discs and suspended above an electrode structure. The deflection of the mirror is controlled by an electric field between the wafer and the electrodes. The accuracy of the shape of the mirror is the most critical since it determines the resolution of the helium microscope. The required modeling of the mirror shape depends on initial quality of the wafer. Therefore it is planned to make various improvements to the mirror at both the macroscopic and atomic levels. This paper is focused on measurements of flatness and thickness of the wafer with high accuracy using specialized optics based techniques, so that the technological process of the wafers could be modified to obtain high quality material.

The paper demonstrates two microinterferometric techniques applied to fibres and other small transparent objects. They enable simultaneous determination of the directional refractive indices and the thickness of isotropic and anisotropic single-medium fibres. The techniques are based on the Pluta birefracting microinterferometer Biolar PI. The paper includes comparison of different approaches and the error analysis.

In this paper we present an overview of various strategies for image segmentation, showing their advantages and drawbacks. The overview covers most of the methods from the classical statistical methods to model-based techniques, with a focus on color images. The paper concludes with a summary of our approach to identifying interreflection.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Liquid phase epitaxy (LPE) is a suitable technique to produce diode laser-pumped solid state lasers with a planar waveguide structure. The thin films of Nd3+, Ga3+ and Lu3+ doped YAG have been grown form a supercooled molten garnet-flux high temperature solution on undoped YAG substrates by the standard LPE dipping technique. The emission spectra and fluorescence lifetimes have been measured for Nd:YAG layers with different concentration of Nd3+ ions. Additionally, the films were investigated versus concentration of neodymium, gallium and lutetium using ESR, x-ray diffraction and micro interferometric techniques. According to above measurements it can be concluded that the obtained epitaxial structures are of good quality.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The diffraction pattern of a textile fiber observed in the back focal plane of the polarizing microscope is used to measure its birefringence. The mathematical model of the phenomenon and the automatic pattern analysis are described.

A band-pass filtering technique has been used in an automated system for detection of early stages of cervical cancer. Practical difficulties of the system and measures taken to overcome them are outlined. A special section is devoted to coherent noise suppression techniques. Some of these methods may be put into real use in many other applications of optical filtering.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Properties and new possible applications of the slit phase contrast (SPhC) technique are presented. They have been tested by the use of an advanced computer simulation program, performing a digital 2D spatial filtering process. A composition of phase objects (e.g., circles, rectangles, gratings, fibers) is transformed into its Fourier form, then multiplied by the transmittance of the phase strip and finally retransformed. Several soot filters have been prepared and applied to a modified, commercial microscope according to the simulation results. The experiments have involved mainly biological specimens. Special attention has been given to measurements of the refractive index profile of the optical fibers. A detailed theoretical background has been presented and results of additional computer simulation based on the operation of convolution have been discussed.

Mass examinations of women should be carried out for early detection of cervical cancer. An automated system for selection of suspicious smears from a large number of negative cases has to be applied. Band-pass spatial frequency filtering technique may be used for the fast reduction of information in the image by converting dark stained nuclei into bright spots. Their intensities depend on the nuclei diameters. The enlarged nucleus is a symptom of the disease. However the filtering system suffers from false alarms produced by amplitude and phase artifacts. In this paper two alternative solutions have been presented. Both employ unequal spectral transmittance of the stain used for sample preparation which is high for infrared and low for the visible spectrum. The first solution consists in the nuclei contrast comparison in visible and infrared light in the direct images. In the second solution helium- neon and infrared diode lasers are used to perform the filtering process and the modified images are compared. The system has been successfully tested on the routine samples.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

International audience; Manipulation of atomic and molecular beams is essential to atom optics applications including atom lasers, atom lithography, atom interferometry and neutral atom microscopy. The manipulation of charge-neutral beams of limited polarisability, spin or excitation states remains problematic, but may be overcome by the development of novel diffractive or reflective optical elements. In this paper we present the first experimental demonstration of atom focusing using an ellipsoidal mirror. The ellipsoidal mirror enables stigmatic off-axis focusing for the first time and we demonstrate focusing of a beam of neutral, ground state helium atoms down to an approximately circular spot, (31.4 ± 0.8) μm x (26.8 ± 0.5) μm in size. This spot size is two orders of magnitude smaller than previous reflective focusing of atomic beams and is a critical milestone towards the construction of a high intensity scanning Helium microscope.

Properties and new possible applications of the slit phase contrast technique are presented. They are tested by an advanced computer simulation program. A digital 2-D spatial filtering process is performed. A composition of phase objects (e.g. , circles, rectangles, gratings, fibers) is transformed into its Fourier form, multiplied by the transmittance of the phase strip, and finally retransformed. According to the simulation results, several soot filters are prepared and applied to a modified commercial microscope. The experiments mainly involve biological specimens. Special attention is given to measurements of the refractive index profile of the optical fibers. A detailed theoretical background is presented and the results of additional computer simulation based on the operation of convolution are discussed.