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Introduction to CODE V: Optics
Introduction to CODE V Training: Day 1 “Optics 101” Digital Camera Design Study User Interface and Customization 3280 East Foothill Boulevard Pasadena, California 91107 USA (626) 795-9101 Fax (626) 795-0184 e-mail: [email protected] World Wide Web: http://www.opticalres.com Copyright © 2009 Optical Research Associates Section 1 Optics 101 (on a Budget) Introduction to CODE V Optics 101 • 1-1 Copyright © 2009 Optical Research Associates Goals and “Not Goals” •Goals: – Brief overview of basic imaging concepts – Introduce some lingo of lens designers – Provide resources for quick reference or further study •Not Goals: – Derivation of equations – Explain all there is to know about optical design – Explain how CODE V works Introduction to CODE V Training, “Optics 101,” Slide 1-3 Sign Conventions • Distances: positive to right t >0 t < 0 • Curvatures: positive if center of curvature lies to right of vertex VC C V c = 1/r > 0 c = 1/r < 0 • Angles: positive measured counterclockwise θ > 0 θ < 0 • Heights: positive above the axis Introduction to CODE V Training, “Optics 101,” Slide 1-4 Introduction to CODE V Optics 101 • 1-2 Copyright © 2009 Optical Research Associates Light from Physics 102 • Light travels in straight lines (homogeneous media) • Snell’s Law: n sin θ = n’ sin θ’ • Paraxial approximation: –Small angles:sin θ~ tan θ ~ θ; and cos θ ~ 1 – Optical surfaces represented by tangent plane at vertex • Ignore sag in computing ray height • Thickness is always center thickness – Power of a spherical refracting surface: 1/f = φ = (n’-n)*c -
Subwavelength Resolution Fourier Ptychography with Hemispherical Digital Condensers
Subwavelength resolution Fourier ptychography with hemispherical digital condensers AN PAN,1,2 YAN ZHANG,1,2 KAI WEN,1,3 MAOSEN LI,4 MEILING ZHOU,1,2 JUNWEI MIN,1 MING LEI,1 AND BAOLI YAO1,* 1State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China 2University of Chinese Academy of Sciences, Beijing 100049, China 3College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710071, China 4Xidian University, Xi’an 710071, China *[email protected] Abstract: Fourier ptychography (FP) is a promising computational imaging technique that overcomes the physical space-bandwidth product (SBP) limit of a conventional microscope by applying angular diversity illuminations. However, to date, the effective imaging numerical aperture (NA) achievable with a commercial LED board is still limited to the range of 0.3−0.7 with a 4×/0.1NA objective due to the constraint of planar geometry with weak illumination brightness and attenuated signal-to-noise ratio (SNR). Thus the highest achievable half-pitch resolution is usually constrained between 500−1000 nm, which cannot fulfill some needs of high-resolution biomedical imaging applications. Although it is possible to improve the resolution by using a higher magnification objective with larger NA instead of enlarging the illumination NA, the SBP is suppressed to some extent, making the FP technique less appealing, since the reduction of field-of-view (FOV) is much larger than the improvement of resolution in this FP platform. Herein, in this paper, we initially present a subwavelength resolution Fourier ptychography (SRFP) platform with a hemispherical digital condenser to provide high-angle programmable plane-wave illuminations of 0.95NA, attaining a 4×/0.1NA objective with the final effective imaging performance of 1.05NA at a half-pitch resolution of 244 nm with a wavelength of 465 nm across a wide FOV of 14.60 mm2, corresponding to an SBP of 245 megapixels. -
Depth of Focus (DOF)
Erect Image Depth of Focus (DOF) unit: mm Also known as ‘depth of field’, this is the distance (measured in the An image in which the orientations of left, right, top, bottom and direction of the optical axis) between the two planes which define the moving directions are the same as those of a workpiece on the limits of acceptable image sharpness when the microscope is focused workstage. PG on an object. As the numerical aperture (NA) increases, the depth of 46 focus becomes shallower, as shown by the expression below: λ DOF = λ = 0.55µm is often used as the reference wavelength 2·(NA)2 Field number (FN), real field of view, and monitor display magnification unit: mm Example: For an M Plan Apo 100X lens (NA = 0.7) The depth of focus of this objective is The observation range of the sample surface is determined by the diameter of the eyepiece’s field stop. The value of this diameter in 0.55µm = 0.6µm 2 x 0.72 millimeters is called the field number (FN). In contrast, the real field of view is the range on the workpiece surface when actually magnified and observed with the objective lens. Bright-field Illumination and Dark-field Illumination The real field of view can be calculated with the following formula: In brightfield illumination a full cone of light is focused by the objective on the specimen surface. This is the normal mode of viewing with an (1) The range of the workpiece that can be observed with the optical microscope. With darkfield illumination, the inner area of the microscope (diameter) light cone is blocked so that the surface is only illuminated by light FN of eyepiece Real field of view = from an oblique angle. -
Introduction to Light Microscopy
Introduction to light microscopy A CAMDU training course Claire Mitchell, Imaging specialist, L1.01, 08-10-2018 Contents 1.Introduction to light microscopy 2.Different types of microscope 3.Fluorescence techniques 4.Acquiring quantitative microscopy data 1. Introduction to light microscopy 1.1 Light and its properties 1.2 A simple microscope 1.3 The resolution limit 1.1 Light and its properties 1.1.1 What is light? An electromagnetic wave A massless particle AND γ commons.wikimedia.org/wiki/File:EM-Wave.gif www.particlezoo.net 1.1.2 Properties of waves Light waves are transverse waves – they oscillate orthogonally to the direction of propagation Important properties of light: wavelength, frequency, speed, amplitude, phase, polarisation upload.wikimedia.org 1.1.3 The electromagnetic spectrum 퐸푝ℎ표푡표푛 = ℎν 푐 = λν 퐸푝ℎ표푡표푛 = photon energy ℎ = Planck’s constant ν = frequency 푐 = speed of light λ = wavelength pion.cz/en/article/electromagnetic-spectrum 1.1.4 Refraction Light bends when it encounters a change in refractive index e.g. air to glass www.thetastesf.com files.askiitians.com hyperphysics.phy-astr.gsu.edu/hbase/Sound/imgsou/refr.gif 1.1.5 Diffraction Light waves spread out when they encounter an aperture. electron6.phys.utk.edu/light/1/Diffraction.htm The smaller the aperture, the larger the spread of light. 1.1.6 Interference When waves overlap, they add together in a process called interference. peak + peak = 2 x peak constructive trough + trough = 2 x trough peak + trough = 0 destructive www.acs.psu.edu/drussell/demos/superposition/superposition.html 1.2 A simple microscope 1.2.1 Using lenses for refraction 1 1 1 푣 = + 푚 = physicsclassroom.com 푓 푢 푣 푢 cdn.education.com/files/ Light bends as it encounters each air/glass interface of a lens. -
The-Pathologists-Microscope.Pdf
The Pathologist’s Microscope The Pathologist’s Microscope Rudolf Virchow, the father of Pathology, had available to him wonderful microscopes during the 1850’s to 1880’s, but the one you have now is far better. Your microscope is the most highly perfected of all scientific instruments. These brief notes on alignment, the objective lens, the condenser, and the eyepieces are what you need to know to get the most out of your microscope and to feel comfortable using it. Figure 1 illustrates the important parts of a generic modern light microscope. Figure 1 - Parts of the Microscope UNC Pathology & Lab Med, MSL, July 2013 1 The Pathologist’s Microscope Alignment August Köhler, in 1870, invented the method for aligning the microscope’s optical system that is still used in all modern microscopes. To get the most from your microscope it should be Köhler aligned. Here is how: 1. Focus a specimen slide at 10X. 2. Open the field iris and the condenser iris. 3. Observe the specimen and close the field iris until its shadow appears on the specimen. 4. Use the condenser focus knob to bring the field iris into focus on the specimen. Try for as sharp an image of the iris as you can get. If you can’t focus the field iris, check the condenser for a flip-in lens and find the configuration that lets you see the field iris. You may also have to move the field iris into the field of view (step 5) if it is grossly misaligned. 5.Center the field iris with the condenser centering screws. -
To Take Into Consideration the Propriety Of
his was the subject for discussion amongst the seventeen microscopists who met at Edwin Quekett’s house No 50 Wellclose Square, in the Borough of Stepney, East London on 3rd September 1839. It was resolved that such a society be formed Tand a provisional committee be appointed to carry this resolution into effect. The appointed provisional committee of seven were to be responsible for the formation of our society, they held meetings at their homes and drew up a set of rules. They adopted the name ‘Microscopical Society of London’ and arranged a public meeting on the 20th December 1839 at the rooms of the Horticultural Society, 21 Regent Street. Where a Nathaniel Bagshaw Ward © National Portrait Gallery, London President, Treasurer and Secretary were elected, the provisional committee also selected the size of almost airtight containers. Together with George 3 x 1 inch as a standard for glass slides. Loddiges, he saw the potential benefit of protection from sea air damage allowing the transport of plants Each of the members of the provisional committee between continents. This Ward published in 1834 had their own background which we have briefly and eventually his cases enabled the introduction described on the following pages, as you will see of the tea plant to Assam from China and rubber they are a diverse range of professionals. plants to Malaysia from South America. His glass plant cases allowed the growth of orchids and ferns in the Victorian home and in 1842 he wrote a book on the subject. However glass was subject to a tax making cases expensive so Ward lobbied successfully for its repeal in 1845. -
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. -
The Scientific Legacy of Antoni Van Leeuwenhoek
196 Chapter 12 Chapter 12 The Scientific Legacy of Antoni Van Leeuwenhoek This final chapter discusses some of the developments in science on which Antoni van Leeuwenhoek left his mark from his death to the beginning of the 21st century. It will review the influence of his work and listen for the echoes of his name almost three hundred years after his death. Figure 12.1 Nineteenth-century microscope by George Adams with eyepiece, objective, various attachments and a mirror to illuminate the specimen © Koninklijke Brill NV, Leiden, 2016 | doi 10.1163/9789004304307_013 The Scientific Legacy of Antoni Van Leeuwenhoek 197 Microscopy Microscopes have become increasingly complex and more versatile, but much easier to use, since the time of Van Leeuwenhoek. Single-lens microscopes went out of use in the 18th century, when compound microscopes with at least two lenses ‒ an eyepiece and an objective ‒ became the norm. Many innovations came from England. Firstly, the illumination of speci- mens was improved. During Van Leeuwenhoek’s lifetime, John Marshall (1663–1725) had developed a simple illumination system using a mirror attached to the foot of the microscope. John Cuff (1708–1772) used an extra lens, a condenser, in 1744 to concentrate light on the specimen. In 1755, George Adams (1720–1773) developed a microscope with a rotating wheel holding objectives with different powers of magnification. Sliding holders in which a variety of specimens could be mounted at one time can be traced back to the rotating holders on the single-lensed microscopes used by Christiaan Huygens and J. De Pouilly (or Depovilly) in the 1670s, and were developed for use with compound microscopes. -
Simple and Open 4F Koehler Transmitted Illumination System for Low- Cost Microscopic Imaging and Teaching
Simple and open 4f Koehler transmitted illumination system for low- cost microscopic imaging and teaching Jorge Madrid-Wolff1, Manu Forero-Shelton2 1- Department of Biomedical Engineering, Universidad de los Andes, Bogota, Colombia 2- Department of Physics, Universidad de los Andes, Bogota, Colombia [email protected] ORCID: JMW: https://orcid.org/0000-0003-3945-538X MFS: https://orcid.org/0000-0002-7989-0311 Any potential competing interests: NO Funding information: 1) Department of Physics, Universidad de los Andes, Colombia, 2) Colciencias grant 712 “Convocatoria Para Proyectos De Investigación En Ciencias Básicas“ 3) Project termination grant from the Faculty of Sciences, Universidad de los Andes, Colombia. Author contributions: JMW Investigation, Visualization, Writing (Original Draft Preparation) MFS Conceptualization, Funding Acquisition, Methodology, Supervision, Writing(Original Draft Preparation) 1 Title Simple and open 4f Koehler transmitted illumination system for low-cost microscopic imaging and teaching Abstract Koehler transillumination is a powerful imaging method, yet commercial Koehler condensers are difficult to integrate into tabletop systems and make learning the concepts of Koehler illumination difficult. We propose a simple 4f Koehler illumination system that offers advantages with respect to building simplicity, cost and compatibility with tabletop systems, which can be integrated with open source Light Sheet Fluorescence Microscopes (LSFMs). With those applications in mind as well as teaching, we provide -
To Determine the Numerical Aperture of a Given Optical Fiber
TO DETERMINE THE NUMERICAL APERTURE OF A GIVEN OPTICAL FIBER Submitted to: Submitted By: Mr. Rohit Verma 1. Rajesh Kumar 2. Sunil Kumar 3. Varun Sharma 4. Jaswinder Singh INDRODUCTION TO AN OPTICAL FIBER Optical fiber: an optical fiber is a dielectric wave guide made of glass and plastic which is used to guide and confine an electromagnetic wave and work on the principle to total internal reflection (TIR). The diameter of the optical fiber may vary from 0.05 mm to 0.25mm. Construction Of An Optical Fiber: (Where N1, N2, N3 are the refractive indexes of core, cladding and sheath respectively) Core: it is used to guide the electromagnetic waves. Located at the center of the cable mainly made of glass or sometimes from plastics it also as the highest refractive index i.e. N1. Cladding: it is used to reduce the scattering losses and provide strength t o the core. It has less refractive index than that of the core, which is the main cause of the TIR, which is required for the propagation of height through the fiber. Sheath: it is the outer most coating of the optical fiber. It protects the core and clad ding from abrasion, contamination and moisture. Requirement for making an optical fiber: 1. It must be possible to make long thin and flexible fiber using that material 2. It must be transparent at a particular wavelength in order for the fiber to guide light efficiently. 3. Physically compatible material of slightly different index of refraction must be available for core and cladding. -
Numerical Aperture of a Plastic Optical Fiber
International Journal of Innovations in Engineering and Technology (IJIET) Numerical Aperture of A Plastic Optical Fiber Trilochan Patra Assistant professor, Department of Electronics and Communication Engineering Techno India College of Technology, Rajarhat, Newtown, Kolkata-156, West Bengal, India Abstract: - To use plastic optical fibers it is useful to know their numerical apertures. These fibers have a large core diameter, which is very different from those of glass fibers. For their connection a strict adjustment to the properties of the optical systems is needed, injecting the light inside and collecting it outside so as not to increase the losses resulting of their strong absorption. If it is sufficient to inject the light at the input with an aperture lower than the theoretical aperture without core stopping, it is very useful to know the out numerical aperture which is varying with the injection aperture and the length of the fiber, because the different modes may be not coupled and are not similarly absorbed. Here I propose a method of calculating numerical aperture by calculating acceptance angle of the fiber. Experimental result shows that we measure the numerical aperture by calculating the mean diameter and then the radius of the spot circle projected on a graph paper. We also measure the distance of the fiber from the target (graph paper). Then make a ratio between the radius of the spot circle and the distance. From here we calculate the acceptance angle and then numerical aperture by sin of acceptance angle. I. INTRODUCTION In optics, the numerical aperture (NA) of an optical system is a dimensionless number that characterizes the range of angles over which the system can accept or emit light. -
Diffraction Notes-1
Diffraction and the Microscope Image Peter Evennett, Leeds [email protected] © Peter Evennett The Carl Zeiss Workshop 1864 © Peter Evennett Some properties of wave radiation • Beams of light or electrons may be regarded as electromagnetic waves • Waves can interfere: adding together (in certain special circumstances): Constructive interference – peaks correspond Destructive interference – peaks and troughs • Waves can be diffracteddiffracted © Peter Evennett Waves radiating from a single point x x Zero First order First Interference order order between waves radiating from Second Second two points order order x and x x x © Peter Evennett Zero Interference order between waves radiating from two more- First First order order closely-spaced points x and x xx Zero First order First Interference order order between waves radiating from Second Second two points order order x and x x x © Peter Evennett Z' Y' X' Image plane Rays rearranged according to origin Back focal plane Rays arranged -2 -1 0 +1 +2 according to direction Objective lens Object X Y Z © Peter Evennett Diffraction in the microscope Diffraction grating Diffraction pattern in back focal plane of objective © Peter Evennett What will be the As seen in the diffraction pattern back focal plane of this grating? of the microscope in white light © Peter Evennett Ernst Abbe’s Memorial, Jena February1994 © Peter Evennett Ernst Abbe’s Memorial, Jena Minimum d resolved distance Wavelength of λ imaging radiation α Half-aperture angle n Refractive index of medium Numerical Aperture Minimum resolved distance is now commonly expressed as d = 0.61 λ / NA © Peter Evennett Abbe’s theory of microscopical imaging 1.