bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of NO on Diamond C(111)-(2×1) by Band Gap Excitation*
Authors: Hamza A. V. , Kubiak G. D.
Published: February 2023

The adsorption of NO on the diamond C(111)-(2x1) surface was studied in the presence of 226nm laser radiation and in the absence of such excitation. Without laser radiation, sticking was not observed on either the diamond C(111)-(1x1) or the reconstructed (2x1) surfaces for ambient (background) NO exposure in an ultra-high vacuum apparatus. The adsorption probability was estimated to be less than 10-8 based on the detection limit of oxygen in Auger electron spectroscopy of 0.3% of a monolayer. Diamond surfaces exposed to ambient NO (purified at 150 K) and 600 μJ/cm2 laser pulses significantly increased the adsorption of NO (see figure 1). Exposures were performed on and off the A2Σ1/2 (v'=0, J'=13/2) ← X2∏3/2(v"=0,J"=13/2) resonance; no significant differences were found. 226 nm photons were of sufficient energy to excite electrons across the ~5.5 eV band gap in diamond. However, the reaction saturated at an oxygen adatom coverage of less than 2% of a monolayer which suggested the adsorption proceeded on "defect sites" on the surface. The natural type IIa diamond was cleaved in air to expose the (111) surface and mechanically polished with 0.25 μm diamond abrasive in olive oil to produce a hydrogen-saturated surface with a mirror finish. Heating the sample to 800 K gave sharp (1x1) LEED patterns. Heating the sample to above 1275 K to remove the hydrogen produced three rotated domains of the (2x1) reconstructed surface.
A Laser-Induced Desorption Study of The Monohydride Phase on Si (100)
Authors: Sherman M.G. , Lewis L.B. , Weinberg W.H. , Sinniah K. , Yates J.T. , Janda K.C.
Published: February 2023

In this summary, we examine the isothermal recombinative desorption of hydrogen from the monohydride phase on Si (100) [1] and propose a new mechanism for the desorption reaction.
Thresholds of neutral ground state and excited atoms under electron bombardment-an indicator for desorption processes via core excitons
Authors: Wolfrum E. , Husinsky W. , Wurz P. , Betz G. , Hudson L. , Tolk N.
Published: February 2023

A 10 eV to 200 eV electron beam with currents up to 30 µA was used to bombard a LiF single crystal surfaces. The electron beam axis was incident on the target under 45°. The bombarding area had dimensions of approximately 2 by 4 mm. Careful investigations have been done to measure the profile of the electron beam. Radiation of excited states was collimated by a MgF2 lens into a high resolution one meter grating monochromator viewing the crystal surface perpendicularly. Ground state Li atoms have been measured with a quadrupole mass analyzer. The UHV-system maintained a base pressure of less than 3xl0−10 mbar during the measurements. Sample charging, which is a crucial problem with insulators especially at low temperatures, was largely reduced by placing a Mo-mesh with a transmission of 80% over the crystal surface and by using low current densities.
UV Laser Excited Adsorbate-Surface Interactions: NH3, C2H4 and CH2I2 on Al and Oxidized Al Surfaces
Authors: Chuang T. J. , Domen K.
Published: February 2023

In spite of many reports on uv laser enhanced gas-solid interactions, especially on photoetching and vapor deposition of solid materials, mechanistic studies on well characterized surfaces remain relatively few. The questions of quantum yields, molecular selectivities, the energetics of dissociation, surface reaction pathways and desorption mechanisms need clear answers. On metal surfaces, extremely rapid electronic decay via electron-hole pairs and charge-transfers can occur. The outcome can be highly unpredictable. In order to better understand the basic photochemical and/or photothermal processes and their consequences on the surface chemistry, we have used CH2I2 molecules adsorbed on Al2O3, Al and Ag as model systems for investigating the photofragmentation, the reaction and the desorption behavior involving the electronic excitation of the adsorbate (1-3). The study has been extended to include NH3, C2H4 as well as CH2I2 adsorbed on both Al and O2-exposed Al surfaces. The new results are presented here.
Polarized Adsorption on Nacl in Air, Observed By Second Harmonic Generation
Authors: Tepper P. , Zink J.C. , Schmelz H. , Reif J. , Matthias E.
Published: February 2023

The azimuthal dependence of optical second harmonic generation at the surface of centrosymmetric crystals is a sensitive tool for the investigation of geometrical order and structure of these surfaces1-4. The technique consists of irradiating the sample under study by pulsed laser light with a fixed polarization and detecting the second harmonic radiation in reflection, also at fixed polarization. The azimuthal dependence of the nonlinear process is then obtained by rotating the sample about the surface normal. A detailed description of the experimental set-up can be found in Ref.4. This technique provides a sensitive way of probing the surface dipolar susceptibility, in other words the degree of freedom of the electronic motion in the surface layer. Its advantage is that it can be used as well in ultra-high vacuum with clean and defined surfaces as in ambient atmosphere. Hence, it is possible to relate observations under wel1-controlled conditions to identical experiments in a realistic environment.
Surface Modification by Plasmas: X-ray Photoemission Studies
Authors: Thomas J. H.
Published: February 2023

Submicrometer dimension multilevel metallization schemes and ultra-large scale integration requires plasma based reactive ion etching pattern transfer. Crystalline damage (1) and residue layers (2-4) in small area contacts can produce high resistance contacts as the structural dimensions are reduced in size. During reactive ion etch patterning, the silicon surface is subjected to ion bombardment which produces crystalline damage and amorphization of the near surface region (4). The surface is also damaged by the formation of thin films of species which condense out of the plasma. This residue layer, which forms from the extinguishing plasma, is chemically dependant upon the plasma composition, vacuum system and substrate geometry and material. For example, fluorocarbon based reactive ion etching can leave fluoropolymer residue films (5,6).
Interaction of laser light with biological tissue-fundamental ablation processes and applications
Authors: Husinsky W. , Mitterer S. , Grabner G. , Baumgartner I.
Published: February 2023

We have investigated the photo-ablation of human corneal tissue and and found effective, apparently non-conventional-thermal photoablation of human cornea by UV and non-UV-laserlight. Photo-ablation of polymers and human tissue by UV-laserlight has been extensively investigated in the last few years. Its potential application to laser surgery of the cornea has triggered a variety of investigations, comprising both, basic studies of the mechanisms of photoablation of biological-tissue as well as clinical applications for corneal or lens surgery.
The Decomposition of NH3 on Si (111) 7x7 Studied Using Laser-Induced Thermal Desorption
Authors: Koehler B.G. , Coon P.A. , George S.M.
Published: February 2023

Silicon nitride is an important insulator in semiconductor devices. One of the most common methods of forming silicon nitride is nitridation by ammonia decomposition. As is the case with many semiconductor processes, the molecular details of the surface decomposition reaction are not fully understood.
Scanning Tunneling Microscopy and Spectroscopy Studies of Silicon Surface Chemistry
Authors: Avouris Phaedon , Wolkow Robert
Published: February 2023

Conventional techniques for the study of surface electronic structure provide information averaged over a macroscopic area of the sample and do not allow direct association of particular electronic features to specific surface sites. The microscopic understanding of surface chemistry, however, requires such an association since chemistry is a localized phenomenon. We will show that STM provides the unique ability to probe surface chemistry at the atomic level. Reactions of Si (111)-(7x7) will be used as prototypes. Using energy-resolved topographs and atom-resolved scanning tunneling spectra (AR-STS) we can follow the spatial distribution of the reactions among the different dangling-bond sites of the 7x7 surface, probe the electronic structure of these sites, and observe the electronic structure changes induced by the reaction. We find that reaction with NH3 preserves the 7x7 reconstruction but that there is significant selectivity among surface sites. Rest-atom sites are more reactive than ad-atom sites, and center-adatom sites are more reactive than corner-adatom sites. AR-STS reveals rest-atom ↔ adatom interactions at the clean surface which are eliminated by the reaction at rest-atom sites. We will discuss and interpret the observed reactivity differences in terms of silicon hypervalency and reaction-induced lattice strain. Reactions with other gases such as Si2H6 proceed in a similar manner. The reaction with evaporated CaF2 molecules eliminates the 7x7 reconstruction and several different sub-monolayer structures are formed depending on the deposition conditions. We will discuss the topography and bonding in these structures, and the role of steps and other defects in their nucleation. Finally, contrary to the general belief that insulating materials cannot be imaged by the STM we will show that by an appropriate choice of biasing conditions, multilayer insulating CaF2 films can be imaged by the STM. Mechanisms by which insulators can be imaged will be discussed.
Photochemistry at Metal Surfaces
Authors: White J. M.
Published: February 2023

Recently, photon-driven processes at adsorbate substrate interfaces has received considerable attention in the research community and for both fundamental and practical reasons. Among the most recent avenues being pursued is photochemistry at adsorbate-metal interfaces where bond breaking within the adsorbate, surface rearrangement, reaction with coadsorbates, and adsorbate desorption have all been observed in systems where thermal effects can be ruled out. Thus, the quenching of electronically excited states by metallic substrates does not always overwhelm, bond breaking processes.
Photoemission from Si(111) Surfaces Covered with Thick Overlayers of CaF2
Authors: Quiniou B. , Schwarz W. , Wu Z. , Osgood R.M. , Yang Q. , Phillips J.
Published: February 2023

Recently, photoemitted electrons have been considered as a possible source of light-initiated surface reactions1. In particular, for example, the photon energy, 6.4 eV, from an ArF laser, is known to exceed the work function of many materials used in laser processing, such as Si, GaAs, and Cu. In fact, space-charge limited photoemission has been reported by several groups doing illumination of surfaces of these materials2.
Pulsed UV Induced Etching of Silicon: A Time-of-Flight Study
Authors: Paulsen-Boaz Carlotta , Rhodin Thor
Published: February 2023

Understanding the dynamics of the laser-induced chlorine etching of silicon requires clarification of the mechanisms by which the photons interact more or less concurrently with the reacting gas, the surface adsorbate and the silicon substrate. To clarify the etching mechanism it is generally recognized that it is desirable to separate the relative contributions from: excitation and dissociation of the reacting gas, Maxwell-Boltzmann heating of the substrate, formation of an altered surface, dissociation, formation and desorption of surface products, generation of electron-hole pairs id the subsurface and the stimulation of new quantum mechanical channels for reaction.1 Although much work has been done on these effects, most of the studies with some exceptions, have not focused on surface characterization and have been carried out at relatively high laser fluences. Hence, the microstructure and composition of the target surfaces have not always been adequately defined. Interpretation of the reaction mechanisms tend to be obscured by thermal effects and the nature, time and energy features of the emitted products have not always been completely resolved. The objective of this work is to clarify some of these issues. The factors of laser fluence and sample doping are specifically addressed. With reference to our system we have chosen one in which there is no etching in the absence of the photon beam, and gas-photon interactions are minimized at the pressures used.
Photochemical Production of Metallic Gallium on Cleaved Gaas Surfaces: Time-Resolved Measurements Using Laser and Synchrotron Radiation
Authors: Goldenberg S. S. , Long J. P. , Kabler M. N.
Published: February 2023

In the course of investigations of electronic processes on laser excited semiconductor surfaces cleaved in ultrahigh vacuum, we have discovered the accumulation of Ga islands on GaAs (110) induced by laser pulse fluences far below those previously reported for irreversible surface modification.1 We have characterized these islands by core and valence photoelectron spectroscopy and by scanning electron microscopy. The photoemission spectra show a satellite of lower binding energy in the Ga 3d spectra which grows along with a metallic edge in the band gap. Because the Ga islands can be produced at fluences as low as 1 mJ/cm2, for which the lattice temperature rise is insignificant, as described below, it is evident that a photochemical decomposition of the GaAs surface is occurring.
Nanolithography
Authors: Pease R. Fabian
Published: February 2023

Our ability of fashion patterns with features below 100nm is beginning to be put to good use for the microfabrication of devices and even circuits. Achieving economic throughput along with the precision required for sub 100-nm features is an enormous challenge.
Profiling and Light Scattering Studies of Si Surfaces
Authors: Church E. L. , Takacs P. Z. , Stover J. C.
Published: February 2023

There is great interest in the semiconductor industry in the development of light-scattering techniques for the detection of "killer particles" on silicon-wafer surfaces. One of the principal limitations in the performance of such devices is the presence of background scattering or "haze" due to scattering from the random residual microtopography of silicon surfaces [1].
Laser Diagnostics of Film Properties by Coherent Surface Wave Pulses
Authors: Hess Peter
Published: February 2023

Thin and ultrathin films play an increasing role in science and technology. In most cases conventional methods cannot be used to measure the mechanical and elastic properties of these films. Therefore, new techniques for the analysis of layered structures with nanoscale depth resolution are urgently needed.
The Surface Preparation and Photochemistry of CdTe(110)
Authors: Lasky P.J. , Lu P.H. , Luo Y. , Osgood R.M. , Slater D.A.
Published: February 2023

Wide-band-gap II-VI compound semiconductors show great promise for the fabrication of LED's and lasers in the visible range [1]. In this paper we examine fundamental aspects of the processing of the surfaces of such materials, specifically the CdTe(110), surface, utilizing Electron Cyclotron Resonance (ECR) generated plasmas and laser-induced photochemical reactions.
Photoluminescence and Electroluminescence of Ge-Implanted Si/SiO2/Si Structures
Authors: Shcheglov K.V. , Yang C.M. , Atwater H.A.
Published: February 2023

Although it was observation of efficient photoluminescence [PL] from porous silicon that prompted numerous investigations into the optoelectronic properties of group IV semiconductor nanocrystals, there is interest in other related materials which are more robust in various chemical and thermal ambients and which can be easily incorporated into standard silicon VLSI processing. A promising approach that meets the above requisites is synthesis of semiconductor nanocrystals in an SiO2 matrix accomplished by various techniques. In this letter we report on the fabrication of a Ge nanocrystal-based electroluminescent device using ion implantation and precipitation.
STM Characterization of Surface Processing: Semiconductor Etching
Authors: Weaver J.H.
Published: February 2023

Advanced material manufacturing often involves dry chemical etching. Most dry etching processes are done under nonequilibrium conditions at elevated temperature during irradiation by photons, electrons, and ions. While such processes are critical to semiconductor technologies, they are poorly understood -- a limitation that is easily rationalized since processing parameters are interrelated. This presentation will review recent investigations of the role of a subset of the processing parameters by focusing on etching of Si(100)-2×1 and GaAs(110) using halogens.
Morphology Evolution and Ion-Induced Surface Transport During Sputtering
Authors: Mayer T.M. , Chason E. , Kellerman B.K. , Howard A.J.
Published: February 2023

We have investigated the evolution of nanometer-scale surface morphology on crystalline and amorphous substrates during off-normal, heavy and light ion sputtering. We use in-situ X-ray reflectivity to measure kinetics of surface morphology evolution and atomic force microscopy to obtain three dimensional structure of sputtered surfaces. Roughening processes associated with material removal and smoothing processes associated with ion-induced surface transport are combined into a comprehensive kinetic model of surface morphology development.
Development of Surface Morphology During the Initial Stages of CVD Growth
Authors: Adams D.P. , Mayer T.M. , Swartzentruber B.S.
Published: February 2023

We present an investigation of the initial stages of Fe layer growth by thermal decomposition of Fe(CO)5 on Si(100) substrates. Scanning tunneling microscopy has been employed to study the evolution of film morphology. Specifically, this investigation has determined the scaling behavior of average cluster density and cluster size distributions for growth over a range of substrate temperatures (100 - 215°C) and coverages. In general, clusters are found to nucleate on Si terraces showing no preference for dissociation of precursor molecules at Si steps. (See Fig. 1) Fig. 2 shows a plot of average island number / area (and areal coverage) vs. exposure for samples dosed with 1x10-8 Torr of Fe(CO)5 at several different temperatures. Fig. 3 shows the corresponding island size distributions for growth at 165°C. By comparing the morphology of submonolayer films measured by STM to that predicted by a rate equation analysis and kinetic Monte Carlo calculations, we have monitored the relative roles of various kinetic processes on changing layer morphology. The nucleation model that will be presented accounts for various processes occuring during CVD growth including formation of nuclei on the Si starting surface and decomposition of the precursor molecule on pre-existing clusters (either by diffusing to a cluster or by direct impingement from the gas phase) and therefore should accurately predict the evolution of layer morphology for other systems. We have also begun to investigate the influence of surface chemistry on nucleation. Preliminary work involving passivating the Si surface prior to CVD growth will be presented.
Low Energy Focused Ion Beam for Nanofabrication
Authors: Gamo Kenji
Published: February 2023

Maskless fabrication capability and high current density of focused ion beam provide unique applications for microfabrication technology and various new devices and processing techniques have been developed. This paper will discuss some of the recent developments of focused ion beam techniques including low energy focused ion beam technique and in situ fabrication.
Surface Chemistry of GaAs Atomic Layer Epitaxy
Authors: Creighton J. R , Truong C. M.
Published: February 2023

Atomic layer epitaxy (ALE) is a technique which, in principle, yields unparalleled deposition uniformity with precise (i.e. monolayer) thickness control. The technique has been used to deposit compound semiconductors, e.g. GaAs, although the success has not been universally good. In many examples the ALE operating “window” is very small or non-existent. Unintentional carbon doping is another problem which has limited the utility of this technique. In order to address the problems limiting GaAs ALE, we have investigated the surface chemical properties of the standard deposition precursors on GaAs(100) using a variety of surface science diagnostics. Results of these experiments have shed light on the mechanisms of precursor decomposition which lead to film growth and carbon doping. For instance, the kinetics of trimethylgallium (TMGa) decomposition on the Ga-rich and As-rich surfaces, measured by TPD, are in semiquantitative agreement with ALE results. This indicates that the dominant growth mechanism during ALE is heterogeneous in nature. We have also investigated the mechanism of carbon incorporation when using TMGa. Normally, a small fraction of adsorbed methyl (CH3) groups dehydrogenate into methylene (CH2) groups, which are a likely precursor to carbon incorporation. This adsorbate was characterized with vibrational spectroscopies and static SIMS. The rate of CH3 dehydrogenation is consistent with the carbon doping levels obtained during ALE and MOMBE.
Micro-manipulation of mono-disperse hematite particles by optical trapping
Authors: Sato Shunichi , Harada Yasunori , Waseda Yoshio , Sugimoto Tadao
Published: February 2023

Optical trapping technique, which uses a strongly focused laser beam1), has become an important tool for the precise manipulation of micrometer-sized particles such as polystyrene latex spheres2) and biological cells3). Almost the particles shown to be trapped are spheres, because the production of shape-controlled particles in micrometer range was quite difficult. Recently, mono-disperse hematite (α-Fe2O3) particles, of which both the shape and the size are simultaneously well-controlled, are produced by the gel-sol method4). It has been revealed that several types of the particle shape, for example, pseudo-cubic and peanut-type, are obtainable. It is very interesting to apply these shape- and size-controlled particles to optical trapping and investigate the feature of the trapped particles. With regard to the micro structure fabrication, these mono-disperse particles are also attractive to use as model parts. We believe that the micro structure fabrication achieved by using optical trapping will be the basis of nanostructure fabrication because nanometer-sized particles, for example, 26 nm silica1) and 36 nm gold particles5), have been demonstrated to be optically trapped.
Step Height Standards for Calibrating an AFM/STM
Authors: Bennett Jean M. , Puiu Mecky , Hodgkin Van A. , McWaid Thomas
Published: February 2023

Calibration of an AFM/STM requires step standards calibrated on another type of instrument. Typically this is a mechanical stylus profiler that has been calibrated using step height standards that have been measured with an optical interferometer. Since the bar dimensions are a few micrometers wide and a few tens of nanometers high, standard Fizeau-type optical interferometers cannot be used. Several types of optical profilers are suitable for the measurements. The question is, to what accuracy can a step ~20 to 100 nm high be measured? Intercomparisons between instruments in different laboratories suggest that a reasonable value for the accuracy is no better than 1% of the step height value. Examples will be shown and systematic errors relating to specific instruments will be discussed.
VUV Laser (157 nm) Chemical Vapor Deposition of High Quality Amorphous Hydrogenated Silicon: "Chemical Mechanism"
Authors: Karstens H. , Knobloch J. , Winkler A. , Pusel A. , Barth M. , Hess P.
Published: February 2023

Energetic beams provide nonthermal conditions for film synthesis in order to achieve growth processes and material properties that cannot be obtained by using a thermal flux. However, a detailed understanding of the gas phase and surface chemistry responsible for film growth and the resulting material properties has not been achieved for the complex reaction and transport processes involved. In the following it will be shown how the deposition chemistry can be studied using localized initiation of the deposition chemistry by a VUV laser.
Tomographic Analysis of Diode Laser Absorbance Spectra
Authors: McNesby K.L. , Daniel R.G. , Morris J.B. , Miziolek A.W.
Published: February 2023

Absorbances measured using line-of-sight techniques inherently report spectral attenuation integrated along the entire beam path1. At a given frequency, line-of-sight absorbance through a low pressure combusting system may have contributions from gases at several different densities and temperatures corresponding to the light beam passing through different regions in the low pressure containment chamber. The degree to which the line-of-sight path is nonhomogeneous is determined by diffusion and flow dynamics within the low pressure containment chamber. Usually, the region of interest is the flame region where the density of some combustion gases may be less than in cooler portions of the line-of-sight path.
Collisional Relaxation of Highly Vibrationally Excited O2 and a Bimodal Vibrational Distribution of O2 from O3 Photolysis: A Possible Explanation of the "Ozone Deficit Problem"
Authors: Wodtke A. M. , Price J. M. , Rogaski C. A. , Mack J. A.
Published: February 2023

Stimulated emission pumping was used to investigate the collisional relaxation of vibrationally state selected

O
2

(

X
3

Σ
g
−

,
19
≤
v
≤
28

)

. Strong evidence was obtained suggesting that

O
2

(

X
3

Σ
g
−

,
v
≥
26

)

reacts with O2 to form O3 + O. Collisional relaxation at lower vibrational excitation appears to agree well with theoretical models which derive effective information about the interaction potential from ab initio calculations of the (O2)2 van der Waals molecule. This remarkable result shows how existing theories designed to explain vibrational energy transfer at low excitation may be extended to the "chemical energy regime." Results of recent experiments on the photolysis of ozone at 226 nm show that the vibrational distribution of the

O
2

(

X
3

Σ
g
−

,
v

)

is markedly bimodal, with one peak near v = 14 and another at v = 27. The explanation of this is, as yet, completely lacking and represents an interesting fundamental problem for ab initio theory. The production of highly vibrationally excited O2 by ozone photolysis together with the reactivity of highly vibrationally excited O2 may have significant atmospheric consequences. Initial modelling results suggest that the inclusion of highly vibrationally excited O2 may reconcile the long-standing discrepancy between the predicted and observed concentrations of stratospheric ozone.
Laser-Induced Plasma Temperature Determination Using Time-Resolved NH Molecular Spectroscopy
Authors: Plemmons D. H. , Parigger C. , Hornkohl J. O. , Lewis J. W. L.
Published: February 2023

Diatomic molecules such as C2, CN, CH, NO and OH are frequently used in combustion diagnostics.1–3 Fluorescence from several of these molecules has been observed in laser-induced breakdown in various gases and previously reported.4,5 Laser induced breakdown in gases is an alternative means by which excited state diatomic molecules can be produced at high temperature - on the order of 5000 K.
Isotope effects in the pasma-chemical decomposition of carbon dioxide
Authors: Andreev S.N. , Mazurenko A.A. , Ochkin V.N. , Savinov S.Yu. , Tskhai S.N.
Published: February 2023

The carbon dioxide dissociation has been investigated both theoretically and experimentally in nonequilibrium plasma of the glow and high-frequency gas discharges. Vibrational and gas temperature values have been measured for molecules in plasma and the dissociation degree for the isotopes 12C16O2 and 13C16O2 after the exit of the gas from the reactor core has been also measured. CARS and absorbtion spectrometry (with help of frequency tuned diode lasers) methods were used for the investigation.
New Generation of Tunable Diode Laser-Based Systems
Authors: Nadezhdinskii A.I.
Published: February 2023

A family of tunable diode laser-based systems was developed for different applications. The systems are operating under full computer control. Due to the model proposed, diode laser frequency tuning can be predicted with high precision. The computer determines laser operation mode, identifies observed spectral line, and using sprectral data base information, calculates the concentration of molecules to be measured.
Segmentation of Textured Images
Authors: Weber Allan G. , Sawchuk Alexander A.
Published: February 2023

A requirement of any vision system is to segment the image into regions having a set of common characteristics. In many applications, this common characteristic is texture. Texture is a higher order image property, and depends on the statistics of pixels in a local neighborhood. To perform segmentation, the regions of homogeneous higher order statistics must be identified and the spatial boundaries where statistical properties change must be located. These local statistics are derived from measurements within a window whose dimensions are subject to a conflicting set of requirements. Using a spatially large window produces better statistical accuracy in homogenous regions having stationary statistics, but it averages over boundaries between regions of different texture, leading to many incorrectly segmented pixels. Using a spatially small averaging window produces more accurate classifications near texture boundaries, but has poor statistical accuracy compared to the large windows. The optimum window sizes to be used are not known a priori, thus we use a hierarchy of averaging windows having a range of sizes and resolutions. The overall goal is to improve the overall segmentation quality over that obtained at a single resolution.
Model-Guided Vision of a Mobile Robot for Monitoring a Building Environment
Authors: Tsuji Saburo
Published: February 2023

Many research groups have studied autonomous vehicles as a challenge in Artificial Intelligence research [1–3]. These robots plan routs to the specified destination and navigate in the real world using visual or ultrasonic sensors. Most groups assume the environments are indoor but unknown, and their efforts have been concentrated on the problem of building the world model from sensory data with little prior knowledge on the environment.
Differential Motions of a Camera from Image Differentials
Authors: Kanade Takeo
Published: February 2023

This talk presents a new theory for obtaining motion from an image sequence, which relates line correspondences, motion of the viewer, and temporal and spatial differentials of images.
6-Coordinates Retrieval of a Cooperative Target from Two-Dimensional Imaging
Authors: Bretaudeau F. , Sarazin M.
Published: February 2023

Various tasks such as parts handling or space rendez-vous and docking need real time determination of the whole set of space parameters (ref. 1–4). The latter can be easily retrieved from 2-D imaging of small, light reflecting, 3-D patterns previously stuck on the cooperative, target.
A Geometric Representation and Matcher for Recognizing and Positioning 3-D Rigid Objects
Authors: Faugeras O. D.
Published: February 2023

Simple geometric primitives are used to represent 3-D shapes for purposes of recognition and positioning. The hypothesis prediction and verification paradigm is used to solve that problem by estimating best rigid displacements recursively.
Object Boundary Encoding Methodologies with Applications to Computer Vision*
Authors: Jain Anil K. , Paglieroni David W.
Published: February 2023

Boundary encoding algorithms by chain code, run-length code, AR model, Fourier descriptor and B-spline control point are presented. B-splines are shown to have superior utility.
Image Domain Processing for Real Time Invariant Feature Extraction
Authors: Messner Richard A. , Szu Harold H.
Published: February 2023

The feature extraction filter in visual neurophysiology known as the novelty filter1 has been identified to be the first feedback term of the iterative expansion of the sensory mapping point spread function (psf), [S], which was modeled after the human visual system's (HVS) lateral subtractive inhibition (SI) neural mechanism2.
Thresholding Techniques for Zero Crossings
Authors: Sandini Giulio , Torre Vincent
Published: February 2023

The detection of luminance discontinuities often produces edge contours that are perceptually unimportant for the analysis of the scene. To try to remove from the image those "irrelevant" edges is not a simple task due to the fact that this procedure usually involves the choice of rather arbitrary thresholds to be applied to certain measures of the local luminance discontinuity. This threshold is only rarely "image indipendent" and very often its optimal choice is linked to the particular image being processed. For this reason, the most effective thresholding algorithms relay on some information about the image which is either known a-priori or measured from the image itself. Whenever the threshold is not fixed a-priori but it is determined in some manner by the algorithm, the thresholding technique is called adaptive.
Range Sensors and Their Use in Industrial Automation
Authors: Bolles Robert C.
Published: February 2023

Different types of range sensors will be described and compared. Typical processing steps will be presented and their use within application programs will be characterized.
Optical 3-Dimensional Digital Data Acquisition Using Far-field Approximation
Authors: Tamura Poohsan N.
Published: February 2023

A two’s compliment encoding in active multi-stripe projection scheme enables an efficient acqusition of dense range map in bipolar coordinates with a far-field approximation.
3-D Vision Through Digitally Controlled Illumination
Authors: Tamura P.N. , Coppock C.J.
Published: February 2023

A digitally coded structured light illumination provides a high speed data acquisition and a high speed dense range map generation capability without a range ambiguity.
Representing Shape: Bumps, Level Set Graphs, and Gaussian Curvature
Authors: Blicher A. Peter
Published: February 2023

We present here a representation for shape based on some ideas from differential topology. The shapes we are interested in are 2 dimensional surfaces embedded in 3-space, usual objects for vision.
Vision Computing Requirements for the Autonomous Land Vehicle
Authors: Lowrie James W.
Published: February 2023

The autonomous land vehicle program has demonstrated a continuous navigation capability under autonomous visual control. This paper summarizes the accomplishments of the program and identifies critical technology voids in the area of visual processing that must be overcome to achieve the goals of the plannes demonstrations.
Geometry-Free X-Ray Reconstruction Using the Theory of Convex Projections
Authors: Stark Henry , Oskoui-Fard Peyma
Published: February 2023

In problems involving inspection by x-ray tomography it may not always be possible to obtain a full set of parallel-beam or fan-beam views from which to reconstruct an image. This may occur because of: 1) external obstructions; 2) internal obstruction; and 3) restricted data acquisition times. Yet typical reconstruction algorithms such as convolution-back projection (CBP) or the direct Fourier method (DFM) are based on specific geometries and a full set of views.
Optimal Synthetic Discriminant Functions Based on Intensity Constraints
Authors: Kumar B.V.K. Vijaya , Bahri Zouhir , Mahalanobis Abhijit
Published: February 2023

A critical task of machine vision is to identify and locate known reference images in the field of view. Although the simple matched filter is the best for detecting an exactly known signal in additive noise, its performance degrades rapidly as the reference image undergoes distortions such as rotation and scale change. One class of methods suggested for combatting this problem is known as synthetic discriminant functions (SDF)[1]. In this, an image is synthesized such that it yields constant cross-correlation values with a set of training images. If this training set is sufficiently representative of the type of distortions to be encountered, we can expect that this approach yields constant cross-correlation values when tested with non-training images. Recently, much attention has been directed towards increasing the repertoire of the SDF techniques beyond the basic scheme in which the synthesized image is assumed a priori to be a linear combination of the training images. In this paper, we propose a new method in which the cross-correlation outputs are allowed to be complex and which minimizes the output variance. This new technique offers significant reductions in the noise sensitivity of the conventional SDFs.
Optical Preprocessing and the Differentiating Spatial Light Modulator
Authors: Armitage D. , Thackara J. I.
Published: February 2023

Photoaddressed spatial light modulators (SLMs) or light valves generally employ a longitudinal electro-optical effect, where the electro-optic voltage is controlled by a photoactive element (e.g., phototitus, Hughes liquid-crystal light valve).1 These devices provide image amplification and incoherent-to-coherent light conversion. The photoconductive and electro-optic functions can be combined in a single photorefractive material to provide a SLM (Itek Prom).
System Architecture of a SIMD Image Processor Optimized for Morphologic Processing
Authors: Dobaj Anthony P.
Published: February 2023

Utilizing large amounts of data for repetitive tasks, machine vision falls under the category of processes requiring very fast limited instruction set computers. This paper describes the Parallel Micro Image Processor (PMIP), a general purpose SIMD 256-processor micro-sequencer controlled image processor. Danielsson and Levialdi describe a method for computing the "degree of parallelism" 1 which tells the speed potential of a system. The PMIP has a degree of parallelism of 2560 compared with 112 for GLOPR (Perkin Elmer) and 6336 for the Cytocomputer (ERIM). Section 2 describes the host interface. Section 3 describes the video I/O structure of the PMIP. Of particular interest is its high bandwidth and variable offset grabbing capability within the field-of-view (FOV). Section 4 describes the processor architecture itself, section 5 describes the specialized feature extraction hardware and section 6 describes the programming environment.
Invariant Pattern Recognition Using Quantum-Limited Images
Authors: Isberg Thomas A. , Morris G. Michael
Published: February 2023

In recent papers by Sheng and Arsenault1, and Wu and Stark2, rotation-, scale-and position-invariant image recognition was achieved by combining the rotation-invariant properties of the circular harmonic expansion with the scale-invariant properties of the Mellin transform. This combination was shown to provide a method for image recognition that is robust in the presence of noise, in addition to its desirable invariant properties. However, the computational complexity of these methods makes it is difficult to implement the recognition algorithms in real time.
Imaging Submicron Structures
Authors: Dainty J C
Published: February 2023

The problem of interpreting images produced by microscopy is not new, but recent applications in optical inspection of VLSI wafers pose some interesting new questions. In this case, it is essential to understand the physics of the image formation so that sensible algorithms that are insensitive to noise can be developed for automated quality control.
Template-Set Approach to Defect Detection and Classification for VLSI Patterns
Authors: Chae Soo-Ik , Walker James T. , Fu Chong-Cheng , Dameron David H. , Pease R. Fabian
Published: February 2023

Automatic inspection of VLSI circuit patterns on photomasks and wafers is increasingly important as the minimum feature size decreases. Real-time inspection at the standard video rate is demanding because the volume of information in VLSI circuits patterns is enormously large. Similar to printed wiring board inspection[1], the goal of VLSI pattern inspection is not only to detect defects, but also to automatically interpret defects for patterning process analysis and control, which is essential to manufacturing automation. However, die-to-die or die-to-database comparison methods employed in most state-of-the-art VLSI pattern inspection systems have only defect detection capability. Simultaneous detection and classification of defects in real time has been challenging because of the complexity of computation required in statistical and syntactic classification methods[2]. We have developed a new approach based on template matching of local binary images with content-addressable memories (CAMs), which can easily be implemented in VLSI circuits because of its modularity and regularity. In a work reported previously[3], this approach was applied primarily to defect detection. Here we focus on its application to defect classification and its system implementation in VLSI circuits.
Determining Scene Structure from a Moving Camera: Epipolar-Plane Image Analysis *
Authors: Baker H. Harlyn , Bolles Robert C. , Marimont David H.
Published: February 2023

We present a new approach to depth measurement of a static scene. It combines the advantages of narrow and wide baseline imaging - giving easier matching and greater accuracies. The technique works with a sequence of images, and unifies the spatial and temporal analysis of data obtained from a camera moving in a straight line. The technique is based on the use of a dense sequence of images - images taken sufficiently close together that they have not only spatial but also temporal continuity. The sequence of data then forms a volume, slices of which directly encode both the three-dimensional positions of objects and such spatio-temporal events as the occlusion of one object by another. We will discuss the theory behind this technique, describe our implementations of the process, and present our current results. Our final discussion will deal with the direction in which we are taking the work: obtaining coherent three-dimensional descriptions of scene depth.
A Pyramid "Smart Sensor" for Machine Vision
Authors: Burt Peter J.
Published: February 2023

A practical vision system must gather information selectively from a complex environment, adapting its sampling strategy dynamically to scene contents and task requirements. Such "smart sensing" can be performed effectively in a pyramid machine.
Tutorial on Illumination for Optical Inspection and Machine Vision: Part 1
Authors: Goodman Douglas
Published: February 2023

Illumination is critical to image formation since what is imaged is not the object per se but the light that is reflects, transmits, or scatters. This light depends both on the object and the manner in which it is illuminated. The fundamentals of this topic are discussed, as is the design of illumination. An example is illumination for the purpose of enhancing certain features and suppressing others.
Overview of the Shutura International Workshop for Adaptive Optics for Industry and Medicine
Authors: Merkle Fritz , Dainty Christopher , Kudryashov Alexis
Published: February 2023

Summary not available.
Adaptive receive telescope array for coherent free-space laser communications
Authors: Kalmar Andras , Kudielka Klaus H. , Leeb Walter R.
Published: February 2023

Free-space optical communication requires receive and transmit antennas in the form of telescopes. In comparison with single-aperture (“monolithic”) telescopes mainly considered so far, a phased telescope array offers many fundamental advantages: • reduced size of optical elements, • inherent modularity, therefore • redundancy (i. e. graceful degradation instead of total breakdown in case of a subtelescope failure), • reduced overall size and mass, • non-mechanical fine pointing.
An Investigation of Active Optics for Extreme-Ultraviolet Projection Lithography
Authors: Chapman Henry N. , Sweeney Donald W.
Published: February 2023

Projection lithography systems are being developed to print 0.1 μm features over a large field, using extreme ultraviolet (EUV) light of a wavelength of around 13 nm. At this wavelength the optics must be all-reflective with multilayer coatings. Current designs of the projection optics consist of off-axis ringfield systems with three or four mirrors (see Fig. I). The demands of microlithography are that the image must be of high quality across the entire field and within a large depth of focus, and that image distortion must be less than 10 nm. These requirements put severe constraints on the quality of the mirrors, which, in general, must have figure errors better than 0.2 nm rms. Although such tolerances can be met by the present state of the art there are various sources of error which can degrade the optical performance of the system. Of those sources, many may cause only low-frequency, quasi-static errors. These error sources include deformation due to stress of the multilayer coatings, thermal and gravitational loading, optical manufacture, and maintenance and alignment of the system. We are investigating the possibility of actively controlling the figure of the mirrors to correct for such errors and achieve the desired imaging performance. Control of the surface figure may also allow a greater throughput of the system, by being able to accommodate a higher heat load from a more intense EUV source.
Hartmann Sensing at Low Light Levels
Authors: Ash D. L. , Solomon C. J.
Published: February 2023

• This work conducted with atmospheric turbulence in mind i.e. astronomical/satellite imaging • We have developed a computer model of a Shack-Hartmann sensor incorporating shot and ccd read noise with three main aims - • 1. To establish the optimal (pupil plane equivalent) Hartmann sub-aperture size for a given signal-noise scenario. • 2. To explore possible benefits of Bayesian wavefront estimation when operating at low light levels. • 3. To investigate improved slope estimation techniques.
A Test of the Decreased Responsiveness Hypothesis in Retinitis Pigmentosa
Authors: Greenstein Vivienne C. , Hood Donald C.
Published: February 2023

The most fundamental deficit attributable to retinal disease is a reduction in sensitivity to light. Recently we suggested a simple physiological basis for this sensitivity loss (Hood and Greenstein, 1982, Greenstein et al., 1982.). Based upon psychophysical experiments performed on patients with a variety of retinal diseases we hypothesized that in the diseased retina all retinal cells are less responsive to light. That is because of anoxia, or decreased metabolic activity, or some other factor, retinal cells respond to all light intensities with a fraction of the response produced in a non-diseased retina. In fact, much of our data suggest that a simple form of this explanation can be applied to the retinal diseases we studied. It is not surprising that decreased cellular responsiveness occurs in a disease like diabetic retinopathy; it is surprising that the loss in foveal sensitivity found in a group of patients with retinitis pigmentosa (RP) was consistent with this explanation (Greenstein et al. 1984). If sensitivity loss in RP can be attributed entirely to decreased responsiveness then the effects of adding adapting lights are quantitatively predictable. In this paper this hypothesis is tested by collecting foveal data at two levels of steady adaptation on a selected group of RP patients.
Development of blue-yellow discrimination loss with age
Authors: Smith Vivianne C. , Pokorny Joel , Pass Arlene
Published: February 2023

The Farnsworth-Munsell 100-hue (FM 100-hue) test is a sensitive test for clinical evaluation of color vision discrimination. Norms both for total error scores in the population and for inter-eye comparisons as a function of age have been published (Verriest, J. Opt. Soc. Amer. 53:185, 1963; Verriest, van Laethem & Uvijls, Amer. J. Ophthal. 93: 635, 1982). However there are no data describing the development of a color axis with age.