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会议名称:

Modeling Aspects in Optical Metrology

召开年:

2017

召开地:

Munich

会议文集:

Modeling Aspects in Optical Metrology VI: Munich(DE).26-28 June 2017

主办单位:

Society of Photo-Optical Instrumentation Engineers

出版时间:

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  • 题名 作者 来源 发表时间 操作
  • Quantifying parameter uncertainties in optical scatterometry using Bayesian inversion

    作者:Martin Hammerschmidt;Martin Weiser;Xavier Garcia Santiago;Lin Zschiedrich;Bernd Bodermann;Sven Burger; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    We present a Newton-like method to solve inverse problems and to quantify parameter uncertainties. We apply the method to parameter reconstruction in optical scatterometry, where we take into account a priori information and measurement uncertainties using a Bayesian approach. Further, we discuss the influence of numerical accuracy on the reconstruction result.

    关键字:computational metrology; optical metrology; computational lithography; nanolithography; finite-element methods; nanooptics

  • Quantifying parameter uncertainties in optical scatterometry using Bayesian inversion

    Martin Hammerschmidt;Martin Weiser;Xavier Garcia Santiago;Lin Zschiedrich;Bernd Bodermann;Sven Burger;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Metrology and quality assurance for European XFEL long flat mirrors installation

    作者:Idoia Freijo Martin;Maurizio Vannoni;Harald Sinn; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    The European XFEL is a large-scale user facility under construction in Hamburg, Germany. It will provide a transversally fully coherent X-ray radiation with outstanding characteristics: high repetition rate (up to 2700 pulses with a 0.6 milliseconds long pulse train at 10Hz), short wavelength (down to 0.05 run), short pulses (in the femtoseconds scale) and high average brilliance (1.6×10~(25) photons / s / mm~2 / mrad~2/ 0.1% bandwidth). Due to the short wavelength and high pulse energies, mirrors need to have a high-quality surface, have to be very long (1 m), and at the same time an effective cooling system has to be implemented. Matching these tight specifications and assessing them with high-precision optical measurements is very challenging. The mirrors go through a complicated and long process, starting from classical polishing to deterministic polishing, ending with a special coating and a final metrology assessment inside their mechanical mounts just before the installation. The installation itself is also difficult for such big mirrors and needs special care. In this contribution we will explain how we implemented the installation process, how we used the metrology information to optimize the installation procedure and we will show some preliminary results with the first mirrors installed in the European XFEL beam transport.

    关键字:x-rays mirrors; absolute calibration; flatness; interferometry

  • Metrology and quality assurance for European XFEL long flat mirrors installation

    Idoia Freijo Martin;Maurizio Vannoni;Harald Sinn;

    Conference on modeling aspects in optical metrology VI

    2017年

  • B-spline parameterization of the dielectric function and information criteria: The craft of non-overfitting

    作者:Dmitriy V. Likhachev; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    Johs and Hale developed the Kramers-Kronig consistent B-spline formulation for the dielectric function modeling in spectroscopic ellipsometry data analysis. In this article we use popular Akaike, corrected Akaike and Bayesian Information Criteria (AIC, AICc and BIC, respectively) to determine an optimal number of knots for B-spline model. These criteria allow finding a compromise between under- and overfitting of experimental data since they penalize for increasing number of knots and select representation which achieves the best fit with minimal number of knots. Proposed approach provides objective and practical guidance, as opposite to empirically driven or "gut feeling" decisions, for selecting the right number of knots for B-spline models in spectroscopic ellipsometry. AIC, AICc and BIC selection criteria work remarkably well as we demonstrated in several real-data applications. This approach formalizes selection of the optimal knot number and may be useful in practical perspective of spectroscopic ellipsometry data analysis.

    关键字:Spectroscopic ellipsometry; optical modeling; dielectric function; B-splines; information criteria

  • B-spline parameterization of the dielectric function and information criteria: The craft of non-overfitting

    Dmitriy V. Likhachev;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Experimental measurement and numerical analysis of group velocity dispersion in cladding modes of an endlessly single-mode photonic crystal fiber

    作者:Tobias Baselt;Christopher Taudt;Bryan Nelsen;Andres Fabian Lasagni;Peter Hartmann; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    The optical properties of the guided modes in the core of photonic crystal fibers (PCFs) can be easily manipulated by changing the air-hole structure in the cladding. Special properties can be achieved in this case such as endless single-mode operation. Endlessly single-mode fibers, which enable single-mode guidance over a wide spectral range, are indispensable in the field of fiber technology. A two-dimensional photonic crystal with a silica central core and a micrometer-spaced hexagonal array of air holes is an established method to achieve endless single-mode properties. In addition to the guidance of light in the core, different cladding modes occur. The coupling between the core and the cladding modes can affect the endlessly single-mode guides. There are two possible ways to determine the dispersion: measurement and calculation. We calculate the group velocity dispersion (GVD) of different cladding modes based on the measurement of the fiber structure parameters, the hole diameter and the pitch of a presumed homogeneous hexagonal array. Based on the scanning electron image, a calculation was made of the optical guiding properties of the microstructured claddmg. We compare the calculation with a method to measure the wavelength-dependent time delay. We measure the time delay of defined cladding modes with a homemade supercontinuum light source in a white light interferometric setup. To measure the dispersion of cladding modes of optical fibers with high accuracy, a time-domain white-light interferometer based on a Mach-Zehnder interferometer is used. The experimental setup allows the determination of the wavelength-dependent differential group delay of light travelling through a thirty centimeter piece of test fiber in the wavelength range from VIS to NIR. The determination of the GVD using different methods enables the evaluation of the individual methods for characterizing the cladding modes of an endlessly single-mode fiber.

    关键字:endlessly single-mode fiber; cladding modes; photonic crystal fiber; group velocity dispersion

  • Experimental measurement and numerical analysis of group velocity dispersion in cladding modes of an endlessly single-mode photonic crystal fiber

    Tobias Baselt;Christopher Taudt;Bryan Nelsen;Andres Fabian Lasagni;Peter Hartmann;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Digital micromirror device as amplitude diffuser for multiple-plane phase retrieval

    作者:Timothy Joseph T. Abregana;Nathaniel P. Hermosa;Percival F. Almoro; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    Previous implementations of the phase diffuser used in the multiple-plane phase retrieval method included a diffuser glass plate with fixed optical properties or a programmable yet expensive spatial light modulator. Here a model for phase retrieval based on a digital micromirror device as amplitude diffuser is presented. The technique offers programmable, convenient and low-cost amplitude diffuser for a non-stagnating iterative phase retrieval. The technique is demonstrated in the reconstructions of smooth object wavefronts.

    关键字:Wavefront Sensing; Phase Retrieval

  • Digital micromirror device as amplitude diffuser for multiple-plane phase retrieval

    Timothy Joseph T. Abregana;Nathaniel P. Hermosa;Percival F. Almoro;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Optofluidic In-plane Mach-Zehnder Interferometer based on the liquid core/liquid cladding waveguides for Refractive-Index measurements

    作者:Mohammadreza Oraie;Hamid Latifi; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    In this paper, we have employed the L~2 waveguides in order to guide the light into two different arms constructed by the inclusion of an engineered obstacle in front of the input optical port. The light which travels inside the core liquid is coupled into these two arms experiencing different optical paths due to the asymmetric geometry of the obstacle and also the different used cladding liquids. We have used several sets of coupled hydrodynamic-electromagnetic simulations to characterize the interferometer based on the output intensity of the waveguide. The simulation results indicate that this technique has a maximum sensitivity of 595%/RIU and a maximum resolution of 3.3×10~(-6) RIU which depends on the range of flow rate.

    关键字:Interferometer; optofluidic; Mach-zehnder interferometer; Refractive Index measurements, L~2 waveguide

  • Optofluidic In-plane Mach-Zehnder Interferometer based on the liquid core/liquid cladding waveguides for Refractive-Index measurements

    Mohammadreza Oraie;Hamid Latifi;

    Conference on modeling aspects in optical metrology VI

    2017年

  • In-line measuring method for periodical sub-wavelength nanostructures

    作者:Gabriela Alexe;Andreas Tausendfreund;Dirk Stobener;Andreas Fischer; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    The goal of this work is to describe a simulatively designed scatterometry approach for the in-line characterization of sub-wavelength sinusoidal gratings, which are formed on a transparent foil in a roll-to-roll procedure. The challenge is to acquire the 3D information of the workpiece, i.e., to measure the grating height in addition to the grating period with nm precision. The grating period is obtained straightforward from the position of the first order diffraction maxima in the reflection and the transmission region. For determining the grating height, the inverse problem is solved, i.e., the relation between the scattered intensities of the diffraction maxima and the grating height is extracted from light scattering simulations. The measurement uncertainty is evaluated for different instrumentation and simulation parameters, such as the detection and incidence angle, the laser wavelength as well as the input parameters of the simulation. As a result, the measurement uncertainty for the grating period and the height is estimated to 0.3 nm and ≤8 nm, respectively, when using laser light in the visible wavelength range. Large area scanning measurements performed offline using the setup parameters derived from simulations verify the sensitivity of the presented measurement approach for identifying local variations of the spatial surface properties. Depending on the chosen detection system, sampling rates up to the MHz range are feasible meeting the requirements of in-line process control of the roll-to-roll production procedure.

    关键字:nanostructures; scatterometry; diffraction; gratings

  • In-line measuring method for periodical sub-wavelength nanostructures

    Gabriela Alexe;Andreas Tausendfreund;Dirk Stobener;Andreas Fischer;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Numerical Investigations of the Potential for Laser Focus Sensors in Micrometrology

    作者:Joerg Bischoff;Rostyslav Mastylo;Eberhard Manske; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    Laser focus sensors (LFS) attached to a scanning nano-positioning and measuring machine (NPMM) enable near diffraction limit resolution with very large measuring areas up to 200 × 200 mm. Further extensions are planned to address wafer sizes of 8 inch and beyond. Thus, they are preferably suited for micro-metrology on large wafers. On the other hand, the minimum lateral features in state-of-the-art semiconductor industry are as small as a few nanometer and therefore far beyond the resolution limits of classical optics. New techniques such as OCD or ODP a.k.a. as scatterometry have helped to overcome these constraints considerably. However, scatterometry relies on regular patterns and therefore, the measurements have to be performed on special reference gratings or boxes rather than in-die. Consequently, there is a gap between measurement and the actual structure of interest which becomes more and more an issues with shrinking feature sizes. On the other hand, near-field approaches would also allow to extent the resolution limit greatly5 but they require very challenging controls to keep the working distance small enough to stay within the near field zone. Therefore, the feasibility and the limits of a LFS scanner system have been investigated theoretically. Based on simulations of laser focus sensor scanning across simple topographies, it was found that there is potential to overcome the diffraction limitations to some extent by means of vicinity interference effects caused by the optical interaction of adjacent topography features. We think that it might be well possible to reconstruct the diffracting profile by means of rigorous diffraction simulation based on a thorough model of the laser focus sensor optics in combination with topography diffraction in a similar way as applied in OCD. The difference lies in the kind of signal itself which has to be modeled. While standard OCD is based on spectra, LFS utilizes height scan signals. Simulation results are presented for different types of topographies (dense vs. sparse, regular vs. single) with lateral features near and beyond the classical resolution limit. Moreover, the influence of topography height on the detectability is investigated. To this end, several sensor principles and polarization setups are considered such as a dual color pin hole sensor and a Foucault knife sensor. It is shown that resolution beyond the Abbe or Rayleigh limit is possible even with "classical" optical setups when combining measurements with sophisticated profile retrieval techniques and some a-pnon knowledge. Finally, measurement uncertainties are derived based on perturbation simulations according to the method presented in.

    关键字:Laser focus sensor; focus sensing; diffraction modeling; surface topography; surface metrology; profilometry; confocal sensors; astigmatic focus sensors

  • Numerical Investigations of the Potential for Laser Focus Sensors in Micrometrology

    Joerg Bischoff;Rostyslav Mastylo;Eberhard Manske;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Evaluation of a human corneal surface with the null-screen method

    作者:Victor de Emanuel Armengol-Cruz;Manuel Campos-Garcia;Cesar Cossio-Guerrero; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    In this work, we design a conical null-screen for testing non-symmetric corneas. We proposed a custom evaluation algorithm in order to calculate the shape of the corneal surface. This data is fitting to a custom non-symmetrical shape surface, taking into account orthogonal polynomials, in order to obtain the geometrical parameters such as the radius of curvature and conical constant. In order to proof our proposal, we perform some corneal topography measurements.

    关键字:Corneal Topography; Non-symmetrical Aspherics; Null-screen; Free-form Surface; Optical Metrology

  • Evaluation of a human corneal surface with the null-screen method

    Victor de Emanuel Armengol-Cruz;Manuel Campos-Garcia;Cesar Cossio-Guerrero;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Simulation of the Influence of Line Edge Roughness on the Performance of Deep Ultraviolet Wire Grid Polarizers

    作者:Thomas Siefke;Carol B. Rojas Hurtado;Johannes Dickmann;Martin Heusinger;Stefanie Kroker; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    Controlling the polarization of light is crucial in numerous applications such as spectroscopy, ellipsometry, photo lithography or industrial vision. Polarization control can be realized by wire grid polarizers (WGPs), which are large aspect ratio, zero order gratings. These elements provide an anisotropic transmittance depending on the polarization direction of the incident light. WGPs' high attractiveness originates from their large free aperture, while simultaneously being extremely thin. Furthermore, these elements can be easily integrated into other nano-optical devices. Recently, such elements were successfully developed for applications down to the deep ultra violet spectral range. However, at shorter wavelengths the influence of roughness of the structures poses a severe limitation on the feasible optical performance. To tackle this problem, we numerically simulated the impact of line edge roughness on the polarization properties of WPGs. Therefore, we generated edge position data of rough grating lines by means of the Thorsos method and calculated the resulting optical response by finite difference time domain method. With this procedure the influence of standard deviation, correlation length, Hurst exponents and wavelength was investigated. We find that for standard deviations of 2.5 nm and 5.0 ran the polarization contrast is reduced by a factor of 3 and 7, respectively. The polarization contrast shows a minimum for intermediate correlation lengths, while virtually no impact of the Hurst exponent is observed. This is explained by several mechanisms occurring for different ratios between the spatial frequency of the roughness and the frequency of incident light. Our theoretical findings correlate well with experimental results we retrieved with measured roughness parameters of fabricated elements.

    关键字:Wire grid polarizer; line edge roughness; simulation; deep ultra violet

  • Simulation of the Influence of Line Edge Roughness on the Performance of Deep Ultraviolet Wire Grid Polarizers

    Thomas Siefke;Carol B. Rojas Hurtado;Johannes Dickmann;Martin Heusinger;Stefanie Kroker;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Role of coherence in microsphere-assisted nanoscopy

    作者:Stephane Perrin;Sylvain Lecler;Audrey Leong-Hoi;Paul C. Montgomery; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    The loss of the information, due to the diffraction and the evanescent waves, limits the resolving power of classical optical microscopy. In air, the lateral resolution of an optical microscope can approximated at half of the wavelength using a low-coherence illumination. Recently, several methods have been developed in order to overcome this limitation and, in 2011, a new far-field and full-field imaging technique was proposed where a sub-diffraction-limit resolution has been achieved using a transparent microsphere. In this article, the phenomenon of super-resolution using microsphere-assisted microscopy is analysed through rigorous electromagnetic simulations. The performances of the imaging technique are estimated as function of optical and geometrical parameters. Furthermore, the role of coherence is introduced through the temporal coherence of the light source and the phase response of the object.

    关键字:Far-field nanoscopy; super-resolution; microsphere; temporal coherence

  • Role of coherence in microsphere-assisted nanoscopy

    Stephane Perrin;Sylvain Lecler;Audrey Leong-Hoi;Paul C. Montgomery;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Optical Vortex Microscope with the simple phase object- theoretical model and its experimental verification

    作者:Agnieszka Popiolek-Masajada;Jan Masajada;Piotr Kurzynowski; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    In this work we consider a microscopic optical system in which the beam with an optical vortex illuminates the sample. The sample modifies the geometry of the vortex beam wavefront and the information about it is transferred into the detection plane. It is shown that the beam at the detection plane can be represented by two parts: non-disturbed vortex part and sample part. We propose and test a scheme for recovering the phase changes caused by sample inserted into the vortex beam. The numerical simulations are supported by the experimental work.

    关键字:optical vortices; microscopy; phase recovering

  • Optical Vortex Microscope with the simple phase object- theoretical model and its experimental verification

    Agnieszka Popiolek-Masajada;Jan Masajada;Piotr Kurzynowski;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Two-mirror device for laser scanning systems: Multi-parametric analysis

    作者:Maria-Alexandra Duma;Virgil-Florin Duma; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    Most laser scanners applications require a linear scanning function, i.e., a constant scanning speed. One of the possible and simplest methods to achieve this - for both scanners with rotational (i.e., polygonal) or oscillatory (i.e., galvanometer) mirrors - is to increase the distance between the mirror and the scanned plane. In order to achieve this, we propose and study a simple and low-cost optical configuration with two plane mirrors set at a certain adjustable angle. The multiple reflections of a laser beam on the two mirrors are considered, the number of images produced is deduced, and the total optical path is obtained. The device is considered for a dimensional measurement application, usually called an optical micrometer - in a set-up which includes the two angular mirrors between a laser scanner with oscillatory or rotational mirrors and its objective lens. This simple device increases the path of the laser beam between the scanning mirror and the lens in a compact construct. The linearity of the scanning function is thus increased, while the total size of the system is reduced - with regard to other possible set-ups. A multi-parameter analysis is proposed and briefly pointed out with regard to the characteristics of the system.

    关键字:laser scanners; plane mirrors; optical metrology; geometrical optics; reflective systems; multi-parameter analysis; optical design

  • Two-mirror device for laser scanning systems: Multi-parametric analysis

    Maria-Alexandra Duma;Virgil-Florin Duma;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Numerical solution of deformation of circular membrane of liquid lens under uniform hydrostatic pressure

    作者:Petr Pokorny;Filip Smejkal;Pavel Kulmon;Antonin Miks;Jiff Novak;Pavel Novak;Milan Jirasek;Martin Horak; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    This paper is focused on a theoretical general description of membrane deformation in membrane liquid lenses, which is based on the theory of large deformations of thin plates under uniform hydrostatic loading. The general formulas are derived, leading to a system of differential equations that describe the shape of a deformed membrane. Since an analytical solution cannot be found, numerical methods are applied and the membrane shape is calculated for given practical examples. Further, the dependency of maximal deflection of the membrane on the applied hydrostatic pressure is analysed. For a better understanding and possibility of modelling the membrane shape in an optical design software, the shape is depicted as aspherical. Finally, the theoretical simulations are compared with experimental results for a given membrane and applied loadings. It is clearly seen that the shape of the membrane does not correspond to a sphere even under low applied pressures. Therefore, the presented analysis could have a significant impact in optical design. Using the results of the paper and numerical examples, one can easily model many cases of membrane liquid lenses and exploit the results of the simulation for precise description of optical systems with active components.

    关键字:Membrane liquid lens; shape deformations; metrology

  • Numerical solution of deformation of circular membrane of liquid lens under uniform hydrostatic pressure

    Petr Pokorny;Filip Smejkal;Pavel Kulmon;Antonin Miks;Jiff Novak;Pavel Novak;Milan Jirasek;Martin Horak;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Contact angle measurement by means of a confocal device

    作者:N. Dominguez;C. Garcia;P. Castilla;C. Pizarro;P. Blanco;M. Espinola;J. Arasa; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    This work presents the first results obtained in the validation study of an innovative technique to calculate the contact angle of a solid surface by means of a confocal device, which confirms the reliability and the accuracy of the presented method. A measurement technique has been developed to measure the contact angle with of a confocal device. This technique has the unique advantage of allowing to perform both topography and contact angle measurements in the same location, therefore avoiding any shift in the sample positioning between the two measurements and ensuring the proper location of both measurements in the same area of the sample, thus enhancing the evaluation of the surface energy of the surface. Specifically, this technique uses the confocal device to measure some parameters of the drop, such as the height (h) and the apparent diameter (L), in a top-view configuration. The drop volume is already known and small enough to discard gravity effects, so the shape of the drop can be approximated by a truncated sphere. Several purely geometric calculations are available to calculate the radius de of the drop and subsequently, the contact angle. This work reports the first results of the ongoing validation study of this technique and the several mathematical calculations employed to extract the contact angle value. These initial measurements were performed for a hydrophobic surface with water as a measurement liquid. The contact angles for different set of drops for this sample were also measured by a commercial contact angle meter in side-view configuration, with the same liquid and drop dimensions, in order to verify the validity and the accuracy of the presented technique. This validation of the calculation of the contact angle is the first step for the further validation of the developed measurement method for the surface energy determination.

    关键字:

  • Contact angle measurement by means of a confocal device

    N. Dominguez;C. Garcia;P. Castilla;C. Pizarro;P. Blanco;M. Espinola;J. Arasa;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Hybrid model of arm for analysis of regional blood oxygenation in non-invasive optical diagnostics

    作者:Sylwester Nowocien;Janusz Mroczka; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    The paper presents a new comprehensive approach to modeling and analysis of processes occurring during the blood flow in the arm's small vessels as well as non-invasive measurement method of mixed venous oxygen saturation. During the work, a meta-analysis of available physiological data was performed and based on its result a hybrid model of forearm vascular tree was proposed. The model, in its structure, takes into account a classical nonlinear hydro-electric analogy in conjunction with light-tissue interaction. Several geometries of arm vascular tree obtained from magnetic resonance angiography (MRA) image were analyzed which allowed to proposed the structure of electrical analog network. Proposed model allows to simulate the behavior of forearm blood flow from the vascular tree mechanics point of view, as well as effects of the impact of cuff and vessel wall mechanics on the recorded photoplethysmographic signals. In particular, it allows to analyze the reaction and anatomical effects in small vessels and microcirculation caused by occlusive maneuver in selected techniques, what was of particular interest to authors and motivation to undertake research in this area. Preliminary studies using proposed model showed that inappropriate selection of occlusion maneuver parameters (e.g. occlusion time, cuff pressure etc.), cause dangerous turbulence of blood flow in the venous section of the vascular tree.

    关键字:venous occlusion; blood saturation; forearm model; photoplethysmography

  • Hybrid model of arm for analysis of regional blood oxygenation in non-invasive optical diagnostics

    Sylwester Nowocien;Janusz Mroczka;

    Conference on modeling aspects in optical metrology VI

    2017年

  • A phase field study of stress effects on microstructure formation during laser-aided direct metal deposition process

    作者:Fikret Kh. Mirzade; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    We present a phase-field model for predicting elastic effects on microstructure evolution at the laser-aided direct metal deposition process. We derive a system of governing equations describing coupling effects among phase variable, concentration, thermal and elastic displacement fields based on the principle of entropy production positiveness, in which thermal and concentration expansions, mechanical anisotropy effects, transformation dilatation, and strain dependency on phase transformation are considered. The microstructure model is coupled with a macroscopic thermodynamic model. Effects of thermo-capillary and thermo-gravitation convections are included. The possibility to describe the process of structure formation at the phase interface during the melt crystallization is discussed. This model enables prediction and visualization of grain structures during and after the laser sintering process.

    关键字:Solidification; Phase field method; Microstructure formation; Stress effects; Laser metal deposition; Powder feeding

  • A phase field study of stress effects on microstructure formation during laser-aided direct metal deposition process

    Fikret Kh. Mirzade;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Analysis of instrumental effects on polarization of the polarimetric unit in the high-spectral resolution spectrograph with fiber input for the 6m SAO RAS telescope

    作者:D.E. Kukushkin;D.A. Sazonenko;A.V. Bakholdin;G.G. Valyavin;V.N. Vasilyev; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    The report presents the results of computer simulation of a polarimetric unit of a high spectral resolution spectrograph with fiber optic input for the 6-m telescope of SAO RAS. The module permits evaluating the polarization state of the incoming radiation. The algorithm of calculation of the instrumental polarization introduced by the BTA mam mirror and matching optics of polarimetric unit is based on the Mueller matrices method. The ways of evaluation methods of the degree of polarization, azimuth angle and ellipticity of radiation transmitted through the BTA main mirror and matching optics of polarimetric unit are shown. The obtained results of computer simulation, after comparison with practical data and inevitable insignificant refinements can be taken as a basis for creation of an accurate model of the map of polarization errors introduced by the BTA main mirror and its tools.

    关键字:polarization optics; instrumental polarization; spectrograph; optical design

  • Analysis of instrumental effects on polarization of the polarimetric unit in the high-spectral resolution spectrograph with fiber input for the 6m SAO RAS telescope

    D.E. Kukushkin;D.A. Sazonenko;A.V. Bakholdin;G.G. Valyavin;V.N. Vasilyev;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Assessment of yearly Lidar ratio values in Penang, Malaysia

    作者:Mohd Zubir Matjafri;Wei Ying Khor;Hwee San Lim; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    Lidar ratio (LR) is an important parameter to invert the lidar equation to subsequently get information from the lidar signals. Therefore, it is the objective of this study to assess the LR values for each day to implement into the inversion method. An algorithm has been generated to estimate the lidar ratios in Penang for the Raymetrics ground-based lidar. Daily average humidity and visibility parameters was obtained and the lidar ratios for each day in year 2014 and year 2015 were assessed. It is found that the LR values in the year 2014 and 2015 generally lie in the range from 55 sr to 85 sr. Maximum LR values in the year 2014 and 2015 is 141 sr and 177 sr respectively. Both years has the same minimum LR value of 46 sr. Extreme values are found in both years during the haze events that occurred in Penang. The LR values estimated are valuable as they represent the atmospheric conditions in Penang and plays an utmost important role in the lidar inversion method.

    关键字:Lidar ratio; Lidar; humidity; visibility

  • Assessment of yearly Lidar ratio values in Penang, Malaysia

    Mohd Zubir Matjafri;Wei Ying Khor;Hwee San Lim;

    Conference on modeling aspects in optical metrology VI

    2017年

  • Active marks structure optimization for optical-electronic systems of spatial position control of industrial objects

    作者:Elena A. Sycheva;Aleksandr S. Vasilev;Oleg U. Lashmanov;Valery V. Korotaev; 会议名称:Conference on modeling aspects in optical metrology VI 2017年

    The article is devoted to the optimization of optoelectronic systems of the spatial position of objects. Probabilistic characteristics of the detection of an active structured mark on a random noisy background are investigated. The developed computer model and the results of the study allow us to estimate the probabilistic characteristics of detection of a complex structured mark on a random gradient background, and estimate the error of spatial coordinates. The results of the study make it possible to improve the accuracy of measuring the coordinates of the object. Based on the research recommendations are given on the choice of parameters of the optimal mark structure for use in optical-electronic systems for monitoring the spatial position of large-sized structures.

    关键字:spatial control system; reference marks; image processing; image recognition; active mark; optical-electronic system; large structures

  • Active marks structure optimization for optical-electronic systems of spatial position control of industrial objects

    Elena A. Sycheva;Aleksandr S. Vasilev;Oleg U. Lashmanov;Valery V. Korotaev;

    Conference on modeling aspects in optical metrology VI

    2017年

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(1)要成为系统服务用户必须自行配备上网的所需设备,包括个人微信使用终端、调制解调器或其他必备上网装置,并自行负担个人上网所支付的与此服务有关的网络费用;

(2)用户应向本平台上提供单位名称、姓名、电子邮箱、手机号码,通过手机验证后才能收到外文文献电子邮件;

(3)除按照国家法律法规、第三方(本服务中指国家工程技术图书馆)和本服务要求提供用户的个人资料外,本平台不额外要求用户提供个人隐私信息;

(4)外文文献一经购买,无论用户是否实际使用,不得退款;

(5)外文文献原文是由国家工程技术图书馆负责提供。

2.合理使用

根据相关法律规定,本平台及其所提供的外文期刊、外文会议、外文学位论文和外文科技报告文献仅供购买服务的用户(即授权用户)为个人目的或课堂教学目的使用,授权用户可以对本平台的文献进行以下合理使用:

(1)通过安全网络访问服务器对网络数据库进行检索;

(2)以个人研究和学习为目的,在线阅读检索结果;

(3)通过文献传递获取电子文献供授权用户个人研究和学习使用;

(4)非以商业营利为目的承担正常教学任务的授权用户,为教学需要,可少量复制文献供教学人员使用,同时应指明作者姓名和文献名称。例如授权用户可少量复制作为教学参考资料的文献供从事课堂教授的教师使用,可少量文献复制到供本单位教学使用的内部网络中的安全计算机上,供选修特定课程的学生在该课程课堂教学期间和地点通过内部网络进行阅读。

3.侵权行为

除上述合理使用方式外,不得以任何方式对本平台全部或者部分文献进行复制、出版、发行、传播、转让、商业或其他开发,授权用户以下(但不仅限于以下)超出合理使用范围的行为,属侵犯知识产权行为,须严格禁止:

(1)把外文文献以公共方式提供给非授权用户使用;

(2)利用外文文献对非授权用户提供文献服务;

(3)利用外文文献进行商业服务或支持商业服务;

(4)利用外文文献内容汇编生成二次产品,提供公共或商业服务;

(5)将外文文献使用在任何其他网站或计算机联网环境中,包括但不仅限于在国际互联网和万维网站上。

4.侵权责任

授权用户应在法律规定的其超出合理使用范围内使用本平台提供的文献,若因授权用户的侵权使用行为被相关权利人主张权利而产生任何纠纷、仲裁、诉讼,或遭到国家相关部门处理,由授权用户承担全部法律责任并使本平台方免责,授权用户还应赔偿因上述原因给本平台方造成的全部直接和间接损失,包括但不限于律师费用、诉讼及仲裁费用、财务费用及差旅费等。一经发现用户的使用情况超出著作权法规定的合理使用范围,本平台有权立即封禁该用户的服务账户,并有权终止向用户提供本协议约定的服务而无须承担违约责任。

5.免责声明

(1)本平台仅为根据您的搜索指令提供搜索服务、数据链接服务和电子邮件原文传递服务,搜索结果和原文数据均来自第三方网站,六维联合不会对第三方网站内容作任何实质性的编辑、整理、修改;

(2)本平台对服务及服务所涉文献信息不作任何明示或暗示的保证,包括但不限于服务一定会满足用户的使用要求、服务的及时性、持续性、安全性、准确性以及服务所涉及文献的准确性、完整行、可靠性;

(3)本平台不保证所提供的服务和服务所涉文献信息来源客观准确,对于任何因信赖或使用获取的文献信息,而给用户造成任何直接或间接损失,本平台均不承担责任;本平台不因用户与任何第三方产生的争议或诉讼承担任何责任。

(4)用户签署本协议即意味着理解且不要求六维联合在发生不可抗力情况下承担责任。不可抗力是指不能合理控制、不可预见或即使预见亦无法避免的事件,包括但不限于政府行为、地震、台风、洪水、火灾或其它天灾、战争或任何其它类似事件。鉴于互联网之特殊性质,不可抗力还包含非因本平台原因导致本服务无法正常运行、服务中断或延迟的情形,包括黑客攻击,电信部门技术调整导致之重大影响,因政府管制而造成之暂时关闭,病毒侵袭,网站升级、系统停机维护或通讯终端、电信设备出现故障导致无法进行数据传输等。

6.其他规定

(1)本协议内容受中华人民共和国法律的约束。如果本协议中任何规定被裁定为无效或不可强制执行,该项规定应被撤销,而其余规定继续有效。

(2)本协议的最终解释权归六维联合。

(3)本协议条款可由六维联合随时全部或部分转让。未经六维联合事先明确书面同意,用户不得以任何方式转让本协议条款。

注意:六维联合未就您或其他人士的某项违约行为采取行动,并不表明六维联合就任何继后或类似的违约事件放弃采取行动的权利。


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