# Philip E. Plantz. Application Note. SL-AN-08 Revision C. Provided By: Microtrac, Inc. Particle Size Measuring Instrumentation

Save this PDF as:

Size: px
Start display at page:

Download "Philip E. Plantz. Application Note. SL-AN-08 Revision C. Provided By: Microtrac, Inc. Particle Size Measuring Instrumentation"

## Transcription

1 A Conceptual, Non-Mathematical Explanation on the Use of Refractive Index in Laser Particle Size Measurement (Understanding the concept of refractive index and Mie Scattering in Microtrac Instruments and the effect of particle shape). Philip E. Plantz Application Note Provided By: Microtrac, Inc. Particle Size Measuring Instrumentation

2 1. What happens to light when it interacts with a particle? Because the surface of a particle produces an electromagnetic field due to the presence of electrons and since light represents an electromagnetic radiation, light can interact to produce a phenomenon that is described as diffraction. In diffraction, at some distance from the particle in the direction of the incident light, a pattern will develop which is dependent upon the size of the particle and the wavelength of the incident light. From this pattern, information can be obtained which is related to the size of the particle. Some materials do not transmit light and absorb the energy. In these cases, the substance can be assumed to have an extremely high refractive index as well as a large imaginary component (see Transparent particles below). Under these conditions the calculations can be those described by Fraunhofer. Light can also be reflected from the surface of a particle and the use of such data for particle size measurement would be the subject of a different issue. A third occurrence of light interacting with a particle is a special case and occurs when the particle is somewhat transparent to the incident light. In this case light can pass through the particle much as it would through a diamond. In the case of a diamond, the light is refracted and produces the well-known glitter; however, light passing through a particle may add to the diffraction pattern for a given particle. This effect will be discussed below. 2. What is each of the above dependent upon and how do they interact? As mentioned above, diffraction is solely dependent upon the size of the particle. Reflection has no effect on diffraction but may affect refraction if the surface is sufficiently reflective. The effect on refraction would be to limit the amount of light entering the particle and thus reduce the effect of refraction on a diffraction pattern. Refraction can have considerable impact on a diffraction pattern, but the magnitude of the effect is highly dependent upon the size and shape of the particle. A sphere will transmit the same refraction pattern regardless of the orientation posed to the incident light. In a measuring system where the spherical particle is constantly changing orientation with respect to the incident light, the pattern is always identical and can give rise to well-defined, reinforced extraneous light information that can distort or interfere with the computation of particle size from the diffraction pattern. (Figure 1) The impact of the refracted light is also affected strongly by the shape of the particle. Non-spherical particles can also refract light and may produce a pattern that is superimposed on the diffraction pattern as a spherical particle may. However, the effect is somewhat different. Remember that the particles are in motion and will tumble as a result of the motion. Each portion of the particle will provide a new and different surface for the light to enter and be refracted. Upon exit from the particle, a new refraction pattern emerges which is superimposed on the diffraction pattern. The reinforcing effects observed with a spherical particle do not occur. The refracted pattern is spread across the diffraction pattern as a somewhat constant pattern and affects the diffraction pattern to much less an extent than a spherical particle. (Figure 2) 2

3 3. How does one correct for potential errors in the diffraction pattern that refraction can cause? For spherical particles, the well-accepted concepts embodied in a theory developed by Gustave Mie may be used. This compensation is popularly termed Mie Theory which describes the effect of spherical particle shapes on light. It includes the aspects of refractive index of the particle in relation to the refractive index of the surrounding medium as well as the scattering efficiency 1 (See footnote for definition) of the transparent particle. If the particles are not transparent (such as in the case of carbon black), Mie compensation for refraction is not required while calculation for scattering efficiency must be included. For Microtrac instruments, materials such as dark pigments, carbon black, and metals are considered to be light absorbing (non-transparent). An appropriate selection in Microtrac software addresses this situation where Fraunhofer calculations can be used. Transparent particles. Consider only the case of transparent particles. Also consider that the refractive index has two terms that might be considered to act independently of one another to some degree. These two are recognized by the names real component and imaginary component of refractive index. Each has a particular effect on the compensation in combination with scattering efficiency according to Mie Theory. The assumption that refractive index has no effect on light scattering (true in the case of carbon black) will reduce Mie Theory to the well-known Fraunhofer diffraction concept. Errors can occur in the particle size distribution if Fraunhofer diffraction is applied in situations where the particles are transparent and thus require Mie theory for spherical particles or other compensation for non-spherical particles. N= m-ik where N is the total refractive index which is a combination of the real component (m) for a substance compared to a vacuum and the imaginary component (ik). The terminology extends from the study of complex numbers. In the case of particle size measurement with particles suspended in a fluid, the value k represents the extinction coefficient (related to the absorption coefficient of the material and the wavelength), i is -1 and m is the relative refractive index (RI sample/ RI fluid each of which has been measured compared to a vacuum). To summarize, pure diffracted light is the desirable information that should be used for particle size measurement. The relative refractive index defines where the exiting light will focus and spread while the imaginary component is an indication of the intensity of the refracted light. If the imaginary component is very low, the intensity of the refracted light will be high. Thus, for alumina the equation would be N= 1.76/ ik. The equation can be fulfilled by knowing the value for ik. Unfortunately, such values are NOT readily available in the literature and are difficult to obtain experimentally. Another consideration of the use of the imaginary component is evaluating its influence in calculation of N and the Mie compensation. 1 Scattering efficiency can understood as the relative capability of a particle to scatter light. The amount of light scattered will vary non-linearly with size. 3

4 Since this discussion is a non-mathematical, explanatory, conceptual approach, mathematical proof of the following is not provided, but the reader is encouraged to study the area as it is fully developed from Maxwell s treatment. Summary of the effects of an RI value and its corresponding imaginary component for a particle is presented below. Spherical, Transparent Particles (Figure 1) a. When particles are smaller than 1 micron, transparent and not highly light absorbing (e.g. low index glass), the light path through the particle is very short and absorption of the incident light does not occur and the imaginary term can be assumed to be zero. Remaining is the relative refractive index (ratio of RI values), which continues to have an effect on the pattern resulting by light refracting through the particle. b. When particles are larger than approximately microns, the amount of light transmitted is very low and refraction in general has a very small effect. At sizes much larger than this, the Fraunhofer approximation equations can be used to calculate particle size. c. Within the range of approximately 1-10 microns, there can be effects resulting from the absorption of light, but only if the value for k is of the order (high imaginary values). Values considered to be high would include carbon black (0.66i), and metals (imaginary component can be very high, m is very low due to high reflectance: thus no correction for refraction required and can be treated as Fraunhofer diffraction). Non-spherical, Transparent Particles (Figure 2) a. If the particles are not spherical but are transparent, the compensation (calculation) is not the same as for spherical particles. For NON-SPHERICAL shapes, particle orientation is constantly changing (Figure 2). The refracted components then produce a combined refraction pattern due to the many orientations presented to the incident light. b. The resulting pattern has little definition when combined with the diffraction pattern but still requires some compensation. Since the imaginary component is a minor correction to the relative (real) component, its effect is negligible and can be disregarded. This is shown in Figure 3 where three cases are considered: transparent spherical, transparent non-spherical and absorbing. At the size considered in the diagram, note that a strong resonance feature exists for spherical particles. In comparison, the transparent non- spherical particle having the same size shows extensive reduction of the resonance to the extent that it approaches a completely absorbing particle. In this case, the strict Mie (spherical) calculations should not be used and explains the use of Modified Mie calculations in Microtrac instruments. Also, the refractive component is much less important (but not completely). Since the imaginary component is usually a weak secondary effect compared to the real component, the imaginary component for materials having nonspherical shape, has negligible or insignificant importance. 4

5 4. With what has been discussed, how can the compensation be performed? From the foregoing, several approaches could be developed regarding the issue of refractive index. In one, the concept can be completely disregarded and Fraunhofer diffraction can be used exclusively, but this may result in extraneous refracted light at wider scatter angles which may in turn result in erroneous reporting of distribution tails particularly at the finer particle portion. Mie scattering for spherical particles may be used in combination with relative and imaginary refractive index values, if both are known. This could be applied to both spherical and non-spherical particles (as supported by Figure 3, this may be an unwise choice of calculation options for both types of particle shapes). Usually the imaginary component is not known and selection of the correct value is made empirically by choosing compensation values (both components of refractive index) based upon the operator s opinion of the correct light scattering particle size distribution. The same empirical approach may be used in the instance when both values are unknown. These latter two approaches exhibit undesirable science and provides opportunities for large errors if the particle size should change, even slightly, because the incorrect (unscientific) selection for the values can lead to under- or over- compensation; particularly in regards to the presence or absence of small amount of distribution fines. 5. How does Microtrac treat the issue of refractive index? In consideration of all the above information Microtrac instruments use the following approach described here and shown in Figure 4. For spherical, transparent particles, a requirement exists for the index of refraction of the suspending fluid and the particles. The imaginary component does not require consideration because of the above discussion. In the case of NON-SPHERICAL particles, consideration for refraction is made by selection of the RI sample and RI fluid, which determine the proper compensation to make in the calculations (Microtrac proprietary modified-mie calculations) according to proprietary research and development data. A third option is available for particles that are highly absorbing such as carbon black and toners. Summary The imaginary component of the total refractive index demonstrates little effect on the refraction of light through a particle except in the 1-10 micron region. Even in this region of sizes, the effect is important when the imaginary component is of the order of carbon black (0.66i) or higher (reflective metals). In the case of non-spherical particles refractive index has generally less impact on the calculated particle size distribution but still requires minor compensation from semi-empirically determined data. Under this condition, the imaginary component is of no consequence and can be ignored. In general, the imaginary component can be described as having negligible effect on diffraction light scattering particle size measurement except in highly specific cases, which are rarely encountered. References: 1. Principles of Optics: Electromagnetic theory of propagation, interference and diffraction of light. Max Born and Emil Wolf, 6 th Ed. Pergammon Press 2. Encyclopedic Dictionary of Physics. J Thesis. The Macmillan Company. 3. Vibrations, Waves, and Diffraction. H.J.J. Braddock, B.A., Ph.D. McGraw-Hill Book Company. 4. The Practicing Scientists Handbook. Alfred J. Moses. Van Nostrand Reinhold Company 5

6 Pure Mie Scattering Calculations Apply to Spherical Particles. Figure 1 6

7 1.0 Response Issues Resonance NORMALIZED FLUX μm 20 μm 6 μm Note that the secondary peak from the previous slide is greatly diminished. Light transmitted through nonspherical particles is more spread. Thus Mie Calculations are modified to satisfy this difference from perfect spherical particles DETECTOR SEGMENT Figure 2 7

8 Figure 3 Figure3 above shows the response of light to a 6 micron particle having Refractive Index =1.54. Major peaks (size) are purposely drawn displaced because the patterns are identical for size indication. Note on the right side that non-spherical transparent particle refraction is more similar to an absorbing response than to spherical curve. Microtrac developed special calculations that are used to take this effect of nonspheres into consideration. 8

9 Figure 4 9

10 4

### Philip E. Plantz. Application Note. SL-AN-08 Revision B. Provided By: Microtrac, Inc. Particle Size Measuring Instrumentation

A Conceptual, Non Mathematical Explanation on the Use of Refractive Index in Laser Particle Size Measurement: (Understanding the concept of refractive index and Mie Scattering in Microtrac Instruments

### Particle Size Distribution

Volume (%) How to choose the correct optical properties for a sample a systematic practical approach Introduction ISO 1332 states that Mie scattering theory should be the only theory used to calculate

### specular diffuse reflection.

Lesson 8 Light and Optics The Nature of Light Properties of Light: Reflection Refraction Interference Diffraction Polarization Dispersion and Prisms Total Internal Reflection Huygens s Principle The Nature

### LIGHT SCATTERING THEORY

LIGHT SCATTERING THEORY Laser Diffraction (Static Light Scattering) When a Light beam Strikes a Particle Some of the light is: Diffracted Reflected Refracted Absorbed and Reradiated Reflected Refracted

### Method of determining the optical properties of ceramics and ceramic pigments: measurement of the refractive index

Method of determining the optical properties of ceramics and ceramic pigments: measurement of the refractive index A. Tolosa (1), N. Alcón (1), F. Sanmiguel (2), O. Ruiz (2). (1) AIDO, Instituto tecnológico

### History of Light. 5 th Century B.C.

History of Light 5 th Century B.C. Philosophers thought light was made up of streamers emitted by the eye making contact with an object Others thought that light was made of particles that traveled from

### Chapter 24. Wave Optics

Chapter 24 Wave Optics Wave Optics The wave nature of light is needed to explain various phenomena Interference Diffraction Polarization The particle nature of light was the basis for ray (geometric) optics

### LIGHT. Descartes particle theory, however, could not be used to explain diffraction of light.

1 LIGHT Theories of Light In the 17 th century Descartes, a French scientist, formulated two opposing theories to explain the nature of light. These two theories are the particle theory and the wave theory.

### Chapter 24. Wave Optics. Wave Optics. The wave nature of light is needed to explain various phenomena

Chapter 24 Wave Optics Wave Optics The wave nature of light is needed to explain various phenomena Interference Diffraction Polarization The particle nature of light was the basis for ray (geometric) optics

### Dynamical Theory of X-Ray Diffraction

Dynamical Theory of X-Ray Diffraction ANDRE AUTHIER Universite P. et M. Curie, Paris OXFORD UNIVERSITY PRESS Contents I Background and basic results 1 1 Historical developments 3 1.1 Prologue 3 1.2 The

### Electromagnetic waves

Electromagnetic waves Now we re back to thinking of light as specifically being an electromagnetic wave u u u oscillating electric and magnetic fields perpendicular to each other propagating through space

### Ch. 22 Properties of Light HW# 1, 5, 7, 9, 11, 15, 19, 22, 29, 37, 38

Ch. 22 Properties of Light HW# 1, 5, 7, 9, 11, 15, 19, 22, 29, 37, 38 Brief History of the Nature of Light Up until 19 th century, light was modeled as a stream of particles. Newton was a proponent of

### Chapter 24. Wave Optics. Wave Optics. The wave nature of light is needed to explain various phenomena

Chapter 24 Wave Optics Wave Optics The wave nature of light is needed to explain various phenomena Interference Diffraction Polarization The particle nature of light was the basis for ray (geometric) optics

### Conceptual Physics Fundamentals

Conceptual Physics Fundamentals Chapter 14: PROPERTIES OF LIGHT This lecture will help you understand: Reflection Refraction Dispersion Total Internal Reflection Lenses Polarization Properties of Light

### Physics 202, Lecture 23

Physics 202, Lecture 23 Today s Topics Lights and Laws of Geometric Optics Nature of Light Reflection and Refraction Law of Reflection Law of Refraction Index of Reflection, Snell s Law Total Internal

### ISO INTERNATIONAL STANDARD. Particle size analysis Laser diffraction methods. Analyse granulométrique Méthodes par diffraction laser

INTERNATIONAL STANDARD ISO 13320 First edition 2009-10-01 Corrected version 2009-12-01 Particle size analysis Laser diffraction methods Analyse granulométrique Méthodes par diffraction laser Reference

### Light. Form of Electromagnetic Energy Only part of Electromagnetic Spectrum that we can really see

Light Form of Electromagnetic Energy Only part of Electromagnetic Spectrum that we can really see Facts About Light The speed of light, c, is constant in a vacuum. Light can be: REFLECTED ABSORBED REFRACTED

### f. (5.3.1) So, the higher frequency means the lower wavelength. Visible part of light spectrum covers the range of wavelengths from

Lecture 5-3 Interference and Diffraction of EM Waves During our previous lectures we have been talking about electromagnetic (EM) waves. As we know, harmonic waves of any type represent periodic process

### Particle Size Distribution Analysis of Porous Powders Using the Saturn DigiSizer 5200

Application Note 38 Particle Size Distribution Analysis of Porous Powders Using the Saturn DigiSizer 5200 Porous powders find application in many industries these days. These range from catalysts to pharmaceuticals;

### Chapter 25. Wave Optics

Chapter 25 Wave Optics Interference Light waves interfere with each other much like mechanical waves do All interference associated with light waves arises when the electromagnetic fields that constitute

### Chapter 8: Physical Optics

Chapter 8: Physical Optics Whether light is a particle or a wave had puzzled physicists for centuries. In this chapter, we only analyze light as a wave using basic optical concepts such as interference

### EM Waves Practice Problems

PSI AP Physics 2 Name 1. Sir Isaac Newton was one of the first physicists to study light. What properties of light did he explain by using the particle model? 2. Who was the first person who was credited

### Fiber Optic Communication Systems. Unit-03: Properties of Light. https://sites.google.com/a/faculty.muet.edu.pk/abdullatif

Unit-03: Properties of Light https://sites.google.com/a/faculty.muet.edu.pk/abdullatif Department of Telecommunication, MUET UET Jamshoro 1 Refractive index Department of Telecommunication, MUET UET Jamshoro

### Chapter 22. Reflection and Refraction of Light

Chapter 22 Reflection and Refraction of Light Nature of Light Light has a dual nature. Particle Wave Wave characteristics will be discussed in this chapter. Reflection Refraction These characteristics

### DIFFRACTION 4.1 DIFFRACTION Difference between Interference and Diffraction Classification Of Diffraction Phenomena

4.1 DIFFRACTION Suppose a light wave incident on a slit AB of sufficient width b, as shown in Figure 1. According to concept of rectilinear propagation of light the region A B on the screen should be uniformly

### Diffraction. Single-slit diffraction. Diffraction by a circular aperture. Chapter 38. In the forward direction, the intensity is maximal.

Diffraction Chapter 38 Huygens construction may be used to find the wave observed on the downstream side of an aperture of any shape. Diffraction The interference pattern encodes the shape as a Fourier

### HW Chapter 20 Q 2,3,4,5,6,10,13 P 1,2,3. Chapter 20. Classic and Modern Optics. Dr. Armen Kocharian

HW Chapter 20 Q 2,3,4,5,6,10,13 P 1,2,3 Chapter 20 Classic and Modern Optics Dr. Armen Kocharian Electromagnetic waves and matter: A Brief History of Light 1000 AD It was proposed that light consisted

### Where n = 0, 1, 2, 3, 4

Syllabus: Interference and diffraction introduction interference in thin film by reflection Newton s rings Fraunhofer diffraction due to single slit, double slit and diffraction grating Interference 1.

### Chapter 33 The Nature and Propagation of Light by C.-R. Hu

Chapter 33 The Nature and Propagation of Light by C.-R. Hu Light is a transverse wave of the electromagnetic field. In 1873, James C. Maxwell predicted it from the Maxwell equations. The speed of all electromagnetic

### PHY132 Introduction to Physics II Class 5 Outline:

PHY132 Introduction to Physics II Class 5 Outline: Ch. 22, sections 22.1-22.4 (Note we are skipping sections 22.5 and 22.6 in this course) Light and Optics Double-Slit Interference The Diffraction Grating

### Conceptual Physics 11 th Edition

Conceptual Physics 11 th Edition Chapter 28: REFLECTION & REFRACTION This lecture will help you understand: Reflection Principle of Least Time Law of Reflection Refraction Cause of Refraction Dispersion

### College Physics B - PHY2054C

Young College - PHY2054C Wave Optics: 10/29/2014 My Office Hours: Tuesday 10:00 AM - Noon 206 Keen Building Outline Young 1 2 3 Young 4 5 Assume a thin soap film rests on a flat glass surface. Young Young

### PHYSICS. Chapter 33 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT

PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 33 Lecture RANDALL D. KNIGHT Chapter 33 Wave Optics IN THIS CHAPTER, you will learn about and apply the wave model of light. Slide

### Chapter 37. Wave Optics

Chapter 37 Wave Optics Wave Optics Wave optics is a study concerned with phenomena that cannot be adequately explained by geometric (ray) optics. Sometimes called physical optics These phenomena include:

### Diffraction and Interference Lab 7 PRECAUTION

HB 11-14-07 Diffraction and Interference Lab 7 1 Diffraction and Interference Lab 7 Equipment laser, eye goggles, optical bench, slide holder, slide with 4 single slits, slide with 4 double slits, 11X14

### Topic 9: Wave phenomena - AHL 9.3 Interference

Topic 9.3 is an extension of Topic 4.4. Essential idea: Interference patterns from multiple slits and thin films produce accurately repeatable patterns. Nature of science: (1) Curiosity: Observed patterns

### Physics 1C. Lecture 22A. "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton

Physics 1C Lecture 22A "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton The Nature of Light An interesting question developed as to the nature of

### Light and Sound. Wave Behavior and Interactions

Light and Sound Wave Behavior and Interactions How do light/sound waves interact with matter? WORD Definition Example Picture REFLECTED REFRACTED is the change in direction of a wave when it changes speed

### Chapter 26 Geometrical Optics

Chapter 26 Geometrical Optics 26.1 The Reflection of Light 26.2 Forming Images With a Plane Mirror 26.3 Spherical Mirrors 26.4 Ray Tracing and the Mirror Equation 26.5 The Refraction of Light 26.6 Ray

### Intermediate Physics PHYS102

Intermediate Physics PHYS102 Dr Richard H. Cyburt Assistant Professor of Physics My office: 402c in the Science Building My phone: (304) 384-6006 My email: rcyburt@concord.edu My webpage: www.concord.edu/rcyburt

### Lecture 7 Notes: 07 / 11. Reflection and refraction

Lecture 7 Notes: 07 / 11 Reflection and refraction When an electromagnetic wave, such as light, encounters the surface of a medium, some of it is reflected off the surface, while some crosses the boundary

### 3 Interactions of Light Waves

CHAPTER 22 3 Interactions of Light Waves SECTION The Nature of Light BEFORE YOU READ After you read this section, you should be able to answer these questions: How does reflection affect the way we see

### Scattering/Wave Terminology A few terms show up throughout the discussion of electron microscopy:

1. Scattering and Diffraction Scattering/Wave Terology A few terms show up throughout the discussion of electron microscopy: First, what do we mean by the terms elastic and inelastic? These are both related

### Chapter 37. Interference of Light Waves

Chapter 37 Interference of Light Waves Wave Optics Wave optics is a study concerned with phenomena that cannot be adequately explained by geometric (ray) optics These phenomena include: Interference Diffraction

### Inspection Technology Europe BV Allied NDT Engineers

What is Gloss? Gloss is an optical phenomenon caused when evaluating the appearance of a surface. The evaluation of gloss describes the capacity of a surface to reflect directed light. Why is gloss measured?

### Basic Waves, Sound & Light Waves, and the E & M Spectrum

Basic Waves, Sound & Light Waves, and the E & M Spectrum 1. What are the amplitude and wavelength of the wave shown below? A) amplitude = 0.10 m, wavelength = 0.30 m B) amplitude = 0.10 m, wavelength =

### Lesson Plan Outline for Rainbow Science

Lesson Plan Outline for Rainbow Science Lesson Title: Rainbow Science Target Grades: Middle and High School Time Required: 120 minutes Background Information for Teachers and Students Rainbows are fascinating

### 16/05/2016. Book page 110 and 112 Syllabus 3.18, Snell s Law. cgrahamphysics.com 2016

16/05/2016 Snell s Law cgrahamphysics.com 2016 Book page 110 and 112 Syllabus 3.18, 3.19 Match the words to the objects absorbs transmits emits diffracts disperses refracts reflects Fibre optics Totally

### 10.5 Polarization of Light

10.5 Polarization of Light Electromagnetic waves have electric and magnetic fields that are perpendicular to each other and to the direction of propagation. These fields can take many different directions

### Reflection and Refraction of Light

PC1222 Fundamentals of Physics II Reflection and Refraction of Light 1 Objectives Investigate for reflection of rays from a plane surface, the dependence of the angle of reflection on the angle of incidence.

### (Equation 24.1: Index of refraction) We can make sense of what happens in Figure 24.1

24-1 Refraction To understand what happens when light passes from one medium to another, we again use a model that involves rays and wave fronts, as we did with reflection. Let s begin by creating a short

### Interference of Light

Lab 11. Interference of Light Goals To observe the interference patterns for laser light passing through a single narrow slit, through two closely spaced slits, and through multiple closely spaced slits,

### PHYSICS 1040L LAB LAB 7: DIFFRACTION & INTERFERENCE

PHYSICS 1040L LAB LAB 7: DIFFRACTION & INTERFERENCE Object: To investigate the diffraction and interference of light, Apparatus: Lasers, optical bench, single and double slits. screen and mounts. Theory:

### Light diffraction from colloidal crystals with low dielectric constant modulation: Simulations using single-scattering theory

PHYSICAL REVIEW B 77, 23544 28 Light diffraction from colloidal crystals with low dielectric constant modulation: Simulations using single-scattering theory Alexander Tikhonov, Rob D. Coalson, and Sanford

### Waves & Oscillations

Physics 42200 Waves & Oscillations Lecture 37 Interference Spring 2016 Semester Matthew Jones Multiple Beam Interference In many situations, a coherent beam can interfere with itself multiple times Consider

### Refraction and Polarization of Light

Chapter 9 Refraction and Polarization of Light Name: Lab Partner: Section: 9.1 Purpose The purpose of this experiment is to demonstrate several consequences of the fact that materials have di erent indexes

### Polarization. Components of Polarization: Malus Law. VS203B Lecture Notes Spring, Topic: Polarization

VS03B Lecture Notes Spring, 013 011 Topic: Polarization Polarization Recall that I stated that we had to model light as a transverse wave so that we could use the model to explain polarization. The electric

### INTRODUCTION REFLECTION AND REFRACTION AT BOUNDARIES. Introduction. Reflection and refraction at boundaries. Reflection at a single surface

Chapter 8 GEOMETRICAL OPTICS Introduction Reflection and refraction at boundaries. Reflection at a single surface Refraction at a single boundary Dispersion Summary INTRODUCTION It has been shown that

### Physics 11 - Waves Extra Practice Questions

Physics - Waves xtra Practice Questions. Wave motion in a medium transfers ) energy, only ) mass, only. both mass and energy. neither mass nor energy. single vibratory disturbance that moves from point

### Textbook Assignment #1: DUE Friday 5/9/2014 Read: PP Do Review Questions Pg 388 # 1-20

Page 1 of 38 Page 2 of 38 Unit Packet Contents Unit Objectives Notes 1: Waves Introduction Guided Practice: Waves Introduction (CD pp 89-90) Independent Practice: Speed of Waves Notes 2: Interference and

### WAVE OPTICS-I. A linear source produces cylindrical wavefront. (Draw diagram).

WAVE OPTICS-I Wavefront: It is the locus of points in space which are simultaneously disturbed and are vibrating in same phase. Wavefront can be spherical, plane or cylindrical. Note that the wavefront

### Textbook Reference: Physics (Wilson, Buffa, Lou): Chapter 24

AP Physics-B Physical Optics Introduction: We have seen that the reflection and refraction of light can be understood in terms of both rays and wave fronts of light. Light rays are quite compatible with

### PY106 Class31. Index of refraction. Refraction. Index of refraction. Sample values of n. Rays and wavefronts. index of refraction: n v.

Refraction Index of refraction When an EM wave travels in a vacuum, its speed is: c = 3.00 x 10 8 m/s. In any other medium, light generally travels at a slower speed. The speed of light v in a material

### What is it? How does it work? How do we use it?

What is it? How does it work? How do we use it? Dual Nature http://www.youtube.com/watch?v=dfpeprq7ogc o Electromagnetic Waves display wave behavior o Created by oscillating electric and magnetic fields

### Nanoparticle Optics: Light Scattering Size Determination of Polystryene Nanospheres by Light Scattering and Mie Theory

Nanoparticle Optics: Light Scattering Size Determination of Polystryene Nanospheres by Light Scattering and Mie Theory OUTLINE OF THE PROCEDURE A) Observe Rayleigh scattering from silica nanoparticles.

### Application of MCNP Code in Shielding Design for Radioactive Sources

Application of MCNP Code in Shielding Design for Radioactive Sources Ibrahim A. Alrammah Abstract This paper presents three tasks: Task 1 explores: the detected number of as a function of polythene moderator

### Refraction and Polarization of Light

Chapter 9 Refraction and Polarization of Light Name: Lab Partner: Section: 9.1 Purpose The purpose of this experiment is to demonstrate several consequences of the fact that materials have di erent indexes

### Light, Lenses, Mirrors

Light, Lenses, Mirrors Optics Light is Dual in nature- has both particle and wave properties. Light = range of frequencies of electromagnetic waves that stimulates the eye s retina Facts About Light It

### Digital Sound Ming C. Lin & Zhimin Ren

Digital Sound Ming C. Lin & Zhimin Ren Department of Computer Science University of North Carolina http://gamma.cs.unc.edu/sound How can it be done? Foley artists manually make and record the sound from

### Waves-Refraction. 5. A change in the speed of a wave as it enters a new medium produces a change in 1. frequency 2. period 3. wavelength 4.

1. In which way does blue light change as it travels from diamond into crown glass? 1. Its frequency decreases. 2. Its frequency increases. 3. Its speed decreases. 4. Its speed increases. Base your answers

### Lab 8. Interference of Light

Lab 8. Interference of Light Goals To observe the interference patterns for laser light passing through a single narrow slit, through two closely spaced slits, and through multiple closely spaced slits,

### Refraction of Light. c = m / s. n = c v. The index of refraction is never less than 1. Some common indices of refraction are listed below.

Refraction of Light The speed of light in a vacuum is c = 3.00 10 8 m / s In air, the speed is only slightly less. In other transparent materials, such as glass and water, the speed is always less than

### Design of Electromagnetic Test Sites

Sensor and Simulation Notes Note 533 3 August 2008 Design of Electromagnetic Test Sites Carl E. Baum University of New Mexico Department of Electrical and Computer Engineering Albuquerque New Mexico 87131

### Ray Optics. Lecture 23. Chapter 23. Physics II. Course website:

Lecture 23 Chapter 23 Physics II Ray Optics Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Let s finish talking about a diffraction grating Diffraction Grating Let s improve (more

### Chapter 33. The Nature of Light and Propagation of Light (lecture 1) Dr. Armen Kocharian

Chapter 33 The Nature of Light and Propagation of Light (lecture 1) Dr. Armen Kocharian The Nature of Light Before the beginning of the nineteenth century, light was considered to be a stream of particles

### Interference of Light

Lecture 22 Chapter 22 Physics II Wave Optics: Interference of Light Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Wave Motion Interference Models of Light (Water waves are Easy

### Lecture Wave Optics. Physics Help Q&A: tutor.leiacademy.org

Lecture 1202 Wave Optics Physics Help Q&A: tutor.leiacademy.org Total Internal Reflection A phenomenon called total internal reflectioncan occur when light is directed from a medium having a given index

### PHYS:1200 LECTURE 32 LIGHT AND OPTICS (4)

1 PHYS:1200 LECTURE 32 LIGHT AND OPTICS (4) The first three lectures in this unit dealt with what is for called geometric optics. Geometric optics, treats light as a collection of rays that travel in straight

### Optics of Vision. MATERIAL TO READ Web: 1.

Optics of Vision MATERIAL TO READ Web: 1. www.physics.uoguelph.ca/phys1070/webst.html Text: Chap. 3, pp. 1-39 (NB: pg. 3-37 missing) Chap. 5 pp.1-17 Handbook: 1. study guide 3 2. lab 3 Optics of the eye

### What is Light? What is Electromagnetic Radiation?

What is Light? Light is a form of electromagnetic radiation that can be seen by the eye. What is Electromagnetic Radiation? Electromagnetic radiation is a term used to describe waves that are created by

### Physics 4C Chapter 33: Electromagnetic Waves

Physics 4C Chapter 33: Electromagnetic Waves Our greatest glory is not in never failing, but in rising up every time we fail. Ralph Waldo Emerson If you continue to do what you've always done, you'll continue

### Chapter 24. Wave Optics

Chapter 24 Wave Optics Wave Optics The wave nature of light is needed to explain various phenomena Interference Diffraction Polarization The particle nature of light was the basis for ray (geometric) optics

### Diffraction and Interference of Plane Light Waves

1 Diffraction and Interference of Plane Light Waves Introduction In this experiment you will become familiar with diffraction patterns created when a beam of light scatters from objects placed in its path.

### Single Photon Interference Christopher Marsh Jaime Vela

Single Photon Interference Christopher Marsh Jaime Vela Abstract The purpose of this experiment was to study the dual wave-particle nature of light. Using a Mach-Zehnder and double slit interferometer,

### G3 TWO-SOURCE INTERFERENCE OF WAVES

G3 TWO-SOURCE INTERFERENCE OF WAVES G4 DIFFRACTION GRATINGS HW/Study Packet Required: READ Tsokos, pp 624-631 SL/HL Supplemental: Hamper, pp 424-428 DO Questions pp 631-632 #1,3,8,9,10 REMEMBER TO. Work

### 4.5 Images Formed by the Refraction of Light

Figure 89: Practical structure of an optical fibre. Absorption in the glass tube leads to a gradual decrease in light intensity. For optical fibres, the glass used for the core has minimum absorption at

### Optics: Laser Light Show Student Advanced Version

Optics: Laser Light Show Student Advanced Version In this lab, you will explore the behavior of light. You will observe reflection and refraction of a laser beam in jello, and use a diffraction pattern

### Textbook Reference: Glencoe Physics: Chapters 16-18

Honors Physics-121B Geometric Optics Introduction: A great deal of evidence suggests that light travels in straight lines. A source of light like the sun casts distinct shadows. We can hear sound from

### 13. Brewster angle measurement

13. Brewster angle measurement Brewster angle measurement Objective: 1. Verification of Malus law 2. Measurement of reflection coefficient of a glass plate for p- and s- polarizations 3. Determination

### Diffraction and Interference

Experiment #32 Diffraction and Interference Goals: Perform a quantitative investigation of two-slit interference Explore use of a photodiode to measure light intensity References 1. I. G. Main, Vibrations

### Diffraction. Factors that affect Diffraction

Diffraction What is one common property the four images share? Diffraction: Factors that affect Diffraction TELJR Publications 2017 1 Young s Experiment AIM: Does light have properties of a particle? Or

### Chapter 26 Geometrical Optics

Chapter 26 Geometrical Optics The Reflection of Light: Mirrors: Mirrors produce images because the light that strikes them is reflected, rather than absorbed. Reflected light does much more than produce

### Characteristics of Light

Characteristics of Light The Nature of Light Light is electromagnetic energy that stimulates the photoreceptor cells in the retina of the eye. This form of energy is our most important means of learning

### CODA -- COmputerizeD Auralization

CODA -- COmputerizeD Auralization MARJAN SIKORA, B. Sc., Faculty of Engineering and Computing, Zagreb, Croatia HRVOJE DOMITROVIĆ, Mr. Sc., Faculty of Engineering and Computing, Zagreb, Croatia CODA (COmputerizeD

### Chapter 24. Wave Optics

Chapter 24 Wave Optics hitt1 An upright object is located a distance from a convex mirror that is less than the mirror's focal length. The image formed by the mirror is (1) virtual, upright, and larger

### PY212 Lecture 25. Prof. Tulika Bose 12/3/09. Interference and Diffraction. Fun Link: Diffraction with Ace Ventura

PY212 Lecture 25 Interference and Diffraction Prof. Tulika Bose 12/3/09 Fun Link: Diffraction with Ace Ventura Summary from last time The wave theory of light is strengthened by the interference and diffraction

### PHYSICS. Chapter 34 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT

PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 34 Lecture RANDALL D. KNIGHT Chapter 34 Ray Optics IN THIS CHAPTER, you will learn about and apply the ray model of light Slide 34-2

### Diffraction: Propagation of wave based on Huygens s principle.

Diffraction: In addition to interference, waves also exhibit another property diffraction, which is the bending of waves as they pass by some objects or through an aperture. The phenomenon of diffraction