Translucency Perception: a Review
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Dispersion and Filters
Optical Filters: Dispersion and Filters Turan Erdogan, PhD (CTO and Co-founder) Semrock, A Unit of IDEX Corporation May 31, 2011 www.semrock.com Dispersion matters sometimes • Often we can sufficiently characterize the spectral performance of an optical filter by determining simply the amount of light intensity (I) it transmits (T(λ)) and it reflects (R(λ)) • T and R are called the “intensity transmission” and “intensity reflection” coefficients filter Iin IT = T(l)Iin IR = R(l)Iin 2 When dispersion matters • However, if the filter is used in an optical system that is sensitive to the phase of the light, we must use the “amplitude transmission” (t exp(iφt)) and “amplitude reflection” (r exp(iφr)) coefficients • t and r determine the amplitude of the electric field of the light that is transmitted and reflected, respectively, and φt and φr determine the change in phase of the electric field • The transmitted and reflected intensity is proportional to the square of the electric field filter 2 Iin = |Ein| phase Ein phase sensitive sensitive optical optical if (l) 2 Et = t(l)e t Ein IT = |Et| 2 system if (l) system IR = |Er| Er = r(l)e r Ein 3 When dispersion matters • Examples of cases when and where phase matters and the amplitude (rather than intensity) coefficients must be used include: . The filter is used in one arm of an interferometer, such that the light transmitted through or reflected off of the filter is coherently combined with light from the other arm or from elsewhere in the system . The filter is used to transmit or reflect a short pulse (<< 1 picosecond) such that its phase can cause the pulse to be chirped and therefore broadened or distorted filter 2 Iin = |Ein| phase Ein phase sensitive sensitive optical optical if (l) 2 Et = t(l)e t Ein IT = |Et| 2 system if (l) system IR = |Er| Er = r(l)e r Ein 4 Impact of optical filter dispersion • Consider the impact of dispersion on a short pulse reflected off of a filter with amplitude reflection coefficient r exp(iφ ) r filter . -
Classical and Modern Diffraction Theory
Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3701993/frontmatter.pdf by guest on 29 September 2021 Classical and Modern Diffraction Theory Edited by Kamill Klem-Musatov Henning C. Hoeber Tijmen Jan Moser Michael A. Pelissier SEG Geophysics Reprint Series No. 29 Sergey Fomel, managing editor Evgeny Landa, volume editor Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3701993/frontmatter.pdf by guest on 29 September 2021 Society of Exploration Geophysicists 8801 S. Yale, Ste. 500 Tulsa, OK 74137-3575 U.S.A. # 2016 by Society of Exploration Geophysicists All rights reserved. This book or parts hereof may not be reproduced in any form without permission in writing from the publisher. Published 2016 Printed in the United States of America ISBN 978-1-931830-00-6 (Series) ISBN 978-1-56080-322-5 (Volume) Library of Congress Control Number: 2015951229 Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3701993/frontmatter.pdf by guest on 29 September 2021 Dedication We dedicate this volume to the memory Dr. Kamill Klem-Musatov. In reading this volume, you will find that the history of diffraction We worked with Kamill over a period of several years to compile theory was filled with many controversies and feuds as new theories this volume. This volume was virtually ready for publication when came to displace or revise previous ones. Kamill Klem-Musatov’s Kamill passed away. He is greatly missed. new theory also met opposition; he paid a great personal price in Kamill’s role in Classical and Modern Diffraction Theory goes putting forth his theory for the seismic diffraction forward problem. -
Image-Space Caustics and Curvatures
Image-space Caustics and Curvatures Xuan Yu Feng Li Jingyi Yu Department of Computer and Information Sciences University of Delaware Newark, DE 19716, USA fxuan,feng,[email protected] Abstract Caustics are important visual phenomena, as well as challenging global illumination effects in computer graph- ics. Physically caustics can be interpreted from one of two perspectives: in terms of photons gathered on scene geom- etry, or in terms of a pair of caustic surfaces. These caustic surfaces are swept by the foci of light rays. In this paper, we develop a novel algorithm to approximate caustic sur- faces of sampled rays. Our approach locally parameterizes rays by their intersections with a pair of parallel planes. We show neighboring ray triplets are constrained to pass simul- taneously through two slits, which rule the caustic surfaces. We derive a ray characteristic equation to compute the two slits, and hence, the caustic surfaces. Using the characteris- tic equation, we develop a GPU-based algorithm to render the caustics. Our approach produces sharp and clear caus- tics using much fewer ray samples than the photon mapping method and it also maintains high spatial and temporal co- herency. Finally, we present a normal-ray surface repre- Figure 1. We use our caustic-surface-based sentation that locally parameterizes the normals about a algorithm to render the refraction caustics surface point as rays. Computing the normal ray caustic cast by a crystal bunny of 69473 triangles. On surfaces leads to a novel real-time discrete shape operator. an NVidia GeForce7800, our method renders at 115 fps at an image resolution of 512x512. -
F I L T E R K
FILTERKIT 322 Woodwork Lane Palatine IL 60067 P: 847-359-3550 F: 847-359-3567 v2.1 [email protected] June16, 2009 www.midopt.com ABOUT MIDWEST OPTICAL SYSTEMS FK100 FILTER KIT CONTENTS ARTICLES Founded in 1988 as a manufacturer of custom precision Our continued commitment to optical components and systems, we have since been innovation has lead to the rotating Machine Vision Filters An overview involved exclusively in the design, manufacture, import Right Angle Attachment (left) that gives you more options for placing and export of vision-specific elements used by a diverse cameras in your system, and the Types of Filters The 8 major types of filters produced by MidOpt for machine vision applications variety of industries and end users. Over time, the company multi-purpose Slip Mount that lets has evolved and is now recognized worldwide as the premier you add filters to lenses when Machine v/s Photographic Filters Why photographic filters are not suitable for machine vision operations resource for filters, lenses and accessories used in industrial (1) there are no filter threads Testing with Filters Testing the effects of filtering and monochromatic lighting imaging applications. and (2) when a filter is desired for use on a wide- Increase Resolution Filters with High-Resolution and Telecentric Lenses; Chromatic Aberration By combining this extensive optics background with our angle lens. expertise in machine vision imaging, MidOpt continues Filter Applications UV Fluorescence, Polarizing, IR Blocking and Light Balancing Filters to develop economical and solutions for industrial image processing that are simply not found elsewhere. We provide FILTER NO. -
UV Optical Filters and Coatings
UV Optical Filters and Coatings BARR PRECISION OPTICS & THIN FILM COATINGS Materion Barr Precision Optics & Thin Film Coatings is a leading manufacturer and supplier of precision optical filters, hybrid circuits, flexible thin films and custom thin film coating services. We offer coating solutions for manufacturers in the defense, commercial, space, science, astronomy and thermal imaging markets. UltraViolet (UV) Optical Filters and Coatings Materion offers Ultraviolet (UV) optical filters and coatings used Material Options Include: in a wide variety of existing and emerging UV-based applications. n Metal-Dielectric Bandpass Filters, fully blocked from Whether the requirement is for small, prototype UV filter quantity, a the UV to IR “one-of-a-kind” coated optic, or for large-scale volume manufactur- n UVA, UVB Filters - fully blocked ing associated with an OEM application, Materion is equipped to n UV Filter Arrays, Discrete and Patterned meet the need. With Materion’s approach to filter design and manu- n UV Bandpass Filters with high transmission – facture, our filter design engineers work closely with our customers’ made with Environmentally-Durable Oxide Films optical system designers throughout the filter development process. n Mercury-line Isolation Filters such as i-line and g-line Filters The optical filters and coatings that result from this collaborative n AR-Coatings for UV Spectral Range process often serve to optimize the performance characteristics n UV Laser Bandpass Filters of our customers’ instruments and applications. When it comes to filter design and manufacture in the UV spectral range, Materion has n Solderable-metalized coatings developed an extensive library of manufacturing plans for UV filters n Wide UV Passband Filters (such as filters in UVC) and coatings which can be deployed or tailored to produce optical blocked for use with SiC or GaN Detectors filters, that best match customer requirements. -
Caustic Architecture Article
Tricks'of'the'light' An#extended#version#of#an#article#in#New$Scientist,#30#January#2013# # Two#men#enter#the#darkened#stage,#apparently#carrying#a#thick#slab#of#badly# made#glass,#like#the#stuff#in#the#windows#of#old#houses#that#turns#the#world# outside#wobbly.#They#hold#it#up,#and#computer#scientist#Mark#Pauly#shines#a# torch#at#it.#The#crowd#in#this#Parisian#auditorium#gasps#and#then#breaks#into# spontaneous#applause.# For#there#on#the#screen#behind,#conjured#out#of#this#piece#of#nearFfeatureless# material#–#not#glass,#in#fact,#but#transparent#acrylic#plastic#(Perspex)#–#is#a# projected#image#of#Alan#Turing,#the#computer#pioneer#whose#centenary#is# celebrated#this#year.#Every#thread#of#his#thick#tweed#jacket#is#picked#out#in#light# and#shadow.#But#where#is#the#image#coming#from?#It#can#only#be#the#transparent# slab,#but#there#seems#to#be#nothing#there#to#produce#it,#nothing#but#a#slightly# uneven#surface.# # An#image#of#Alan#Turing#conjured#from#light#passing#through#a#slab#of#Perspex#at#the# Advances#in#Architectural#Geometry#conference#in#Paris,#September#2012.# This#image#is#made#from#rays#refracted,#folded#and#focused#by#the#slightly# uneven#surface#of#the#acrylic#block.#It’s#similar#to#the#filigree#of#bright#bands#seen# on#the#bottom#of#a#swimming#pool#in#the#sunlight,#called#a#caustic#and#caused#by# the#way#the#wavy#surface#refracts#and#focuses#light.#Caustics#are#familiar#enough,# but#they#never#looked#like#this#before.#Those#made#by#sunlight#shining#through# an#empty#glass#are#a#random#mass#of#cusps#and#squiggles.#Pauly,#a#specialist#in# -
Negative Refractive Index in Artificial Metamaterials
1 Negative Refractive Index in Artificial Metamaterials A. N. Grigorenko Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK We discuss optical constants in artificial metamaterials showing negative magnetic permeability and electric permittivity and suggest a simple formula for the refractive index of a general optical medium. Using effective field theory, we calculate effective permeability and the refractive index of nanofabricated media composed of pairs of identical gold nano-pillars with magnetic response in the visible spectrum. PACS: 73.20.Mf, 41.20.Jb, 42.70.Qs 2 The refractive index of an optical medium, n, can be found from the relation n2 = εμ , where ε is medium’s electric permittivity and μ is magnetic permeability.1 There are two branches of the square root producing n of different signs, but only one of these branches is actually permitted by causality.2 It was conventionally assumed that this branch coincides with the principal square root n = εμ .1,3 However, in 1968 Veselago4 suggested that there are materials in which the causal refractive index may be given by another branch of the root n =− εμ . These materials, referred to as left- handed (LHM) or negative index materials, possess unique electromagnetic properties and promise novel optical devices, including a perfect lens.4-6 The interest in LHM moved from theory to practice and attracted a great deal of attention after the first experimental realization of LHM by Smith et al.7, which was based on artificial metallic structures -
Real-Time Caustics
EUROGRAPHICS 2003 / P. Brunet and D. Fellner Volume 22 (2003), Number 3 (Guest Editors) Real-Time Caustics M. Wand and W. Straßer WSI/GRIS, University of Tübingen Abstract We present a new algorithm to render caustics. The algorithm discretizes the specular surfaces into sample points. Each of the sample points is treated as a pinhole camera that projects an image of the incoming light onto the diffuse receiver surfaces. Anti-aliasing is performed by considering the local surface curvature at the sample points to filter the projected images. The algorithm can be implemented using programmable texture mapping hardware. It allows to render caustics in fully dynamic scenes in real-time on current PC hardware. Categories and Subject Descriptors: I.3.3 [Computer Graphics]: Picture / Image Generation – Display Algo- rithms; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism 1. Introduction tion step has to be performed that is often even more ex- pensive. Thus, the technique is usually not very efficient. A real-time simulation of the interaction of light with Although the implementation techniques for raytracing complex, dynamically changing scenery is still one of the queries have made impressive advances in the last few major challenges in computer graphics. In this paper, we years29, raytracing based algorithms still need a consider- look at a special global illumination problem, rendering of able amount of computational power (such as a cluster of caustics. Caustics occur if light is reflected (or refracted) at several high end CPUs) to calculate global illumination one or more specular surfaces, focused into ray bundles of solutions in real time30. -
Adaptive Spectral Mapping for Real-Time Dispersive Refraction By
Adaptive Spectral Mapping for Real-Time Dispersive Refraction by Damon Blanchette A Thesis Submitted to the Faculty of the WORCESTER POLYTECHNIC INSTITUTE In partial fulfillment of the requirements for the Degree of Master of Science in Computer Science by ___________________________________ January 2012 APPROVED: ___________________________________ Professor Emmanuel Agu, Thesis Adviser ___________________________________ Professor Matthew Ward, Thesis Reader ___________________________________ Professor Craig Wills, Head of Department Abstract Spectral rendering, or the synthesis of images by taking into account the wavelengths of light, allows effects otherwise impossible with other methods. One of these effects is dispersion, the phenomenon that creates a rainbow when white light shines through a prism. Spectral rendering has previously remained in the realm of off-line rendering (with a few exceptions) due to the extensive computation required to keep track of individual light wavelengths. Caustics, the focusing and de-focusing of light through a refractive medium, can be interpreted as a special case of dispersion where all the wavelengths travel together. This thesis extends Adaptive Caustic Mapping, a previously proposed caustics mapping algorithm, to handle spectral dispersion. Because ACM can display caustics in real-time, it is quite amenable to be extended to handle the more general case of dispersion. A method is presented that runs in screen-space and is fast enough to display plausible dispersion phenomena in real-time at interactive frame rates. i Acknowledgments I would like to thank my adviser, Professor Emmanuel Agu, for his guidance, laughs, and answering my hundreds of questions over the year it took to complete this thesis. The beautiful video card helped, too. -
Chapter 19/ Optical Properties
Chapter 19 /Optical Properties The four notched and transpar- ent rods shown in this photograph demonstrate the phenomenon of photoelasticity. When elastically deformed, the optical properties (e.g., index of refraction) of a photoelastic specimen become anisotropic. Using a special optical system and polarized light, the stress distribution within the speci- men may be deduced from inter- ference fringes that are produced. These fringes within the four photoelastic specimens shown in the photograph indicate how the stress concentration and distribu- tion change with notch geometry for an axial tensile stress. (Photo- graph courtesy of Measurements Group, Inc., Raleigh, North Carolina.) Why Study the Optical Properties of Materials? When materials are exposed to electromagnetic radia- materials, we note that the performance of optical tion, it is sometimes important to be able to predict fibers is increased by introducing a gradual variation and alter their responses. This is possible when we are of the index of refraction (i.e., a graded index) at the familiar with their optical properties, and understand outer surface of the fiber. This is accomplished by the mechanisms responsible for their optical behaviors. the addition of specific impurities in controlled For example, in Section 19.14 on optical fiber concentrations. 766 Learning Objectives After careful study of this chapter you should be able to do the following: 1. Compute the energy of a photon given its fre- 5. Describe the mechanism of photon absorption quency and the value of Planck’s constant. for (a) high-purity insulators and semiconduc- 2. Briefly describe electronic polarization that re- tors, and (b) insulators and semiconductors that sults from electromagnetic radiation-atomic in- contain electrically active defects. -
Super-Resolution Imaging by Dielectric Superlenses: Tio2 Metamaterial Superlens Versus Batio3 Superlens
hv photonics Article Super-Resolution Imaging by Dielectric Superlenses: TiO2 Metamaterial Superlens versus BaTiO3 Superlens Rakesh Dhama, Bing Yan, Cristiano Palego and Zengbo Wang * School of Computer Science and Electronic Engineering, Bangor University, Bangor LL57 1UT, UK; [email protected] (R.D.); [email protected] (B.Y.); [email protected] (C.P.) * Correspondence: [email protected] Abstract: All-dielectric superlens made from micro and nano particles has emerged as a simple yet effective solution to label-free, super-resolution imaging. High-index BaTiO3 Glass (BTG) mi- crospheres are among the most widely used dielectric superlenses today but could potentially be replaced by a new class of TiO2 metamaterial (meta-TiO2) superlens made of TiO2 nanoparticles. In this work, we designed and fabricated TiO2 metamaterial superlens in full-sphere shape for the first time, which resembles BTG microsphere in terms of the physical shape, size, and effective refractive index. Super-resolution imaging performances were compared using the same sample, lighting, and imaging settings. The results show that TiO2 meta-superlens performs consistently better over BTG superlens in terms of imaging contrast, clarity, field of view, and resolution, which was further supported by theoretical simulation. This opens new possibilities in developing more powerful, robust, and reliable super-resolution lens and imaging systems. Keywords: super-resolution imaging; dielectric superlens; label-free imaging; titanium dioxide Citation: Dhama, R.; Yan, B.; Palego, 1. Introduction C.; Wang, Z. Super-Resolution The optical microscope is the most common imaging tool known for its simple de- Imaging by Dielectric Superlenses: sign, low cost, and great flexibility. -
(12) Patent Application Publication (10) Pub. No.: US 2013/0258661 A1 Jousse Et Al
US 20130258661A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2013/0258661 A1 Jousse et al. (43) Pub. Date: Oct. 3, 2013 (54) WHTE LED LIGHTING DEVICE AND A Publication Classification LIGHTINGAPPLIANCE (51) Int. Cl. (71) Applicant: MAQUET SAS, Ardon (FR) F2IV 9/10 (2006.01) F2IV33/00 (2006.01) (72) Inventors: Robin Jousse, La Chapelle Saint (52) U.S. Cl. Mesmin (FR); Cécilia Valteau, Ligny Le CPC ............... F2IV 9/10 (2013.01); F2IV33/0068 Ribault (FR); Lionel Comte, La (2013.01) Chapelle Saint Mesmin (FR) USPC ........................................... 362/235; 362/293 (57) ABSTRACT An LED lighting device (6) having an LED (8) emitting white (73) Assignee: MAQUET SAS, Ardon (FR) light and optical filter means (12) suitable for filtering the white light emitted by the LED (8). The optical filter means Appl. No.: 13/793.288 comprise at least two optical filters (12) that have different (21) transmission coefficients and that are positionable to filter the light emitted by the LED (8) individually. The lighting device (22) Filed: Mar 11, 2013 (6) includes a power supply unit (10) suitable for delivering different power supply currents to the LED (8) depending on (30) Foreign Application Priority Data whether one or the other of the optical filters (12) is positioned to filter the light from the LED (8), so as to modify the color Mar. 27, 2012 (FR) ...................................... 12 52735 temperature of the light emitted by the LED (8). Patent Application Publication Oct. 3, 2013 Sheet 1 of 3 US 2013/0258661 A1 S50 8 750 850 Wavelength an Patent Application Publication Oct.