Why Circular Polarization Antenna? FRC Polarization Types
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Polarization Optics Polarized Light Propagation Partially Polarized Light
The physics of polarization optics Polarized light propagation Partially polarized light Polarization Optics N. Fressengeas Laboratoire Mat´eriaux Optiques, Photonique et Syst`emes Unit´ede Recherche commune `al’Universit´ede Lorraine et `aSup´elec Download this document from http://arche.univ-lorraine.fr/ N. Fressengeas Polarization Optics, version 2.0, frame 1 The physics of polarization optics Polarized light propagation Partially polarized light Further reading [Hua94, GB94] A. Gerrard and J.M. Burch. Introduction to matrix methods in optics. Dover, 1994. S. Huard. Polarisation de la lumi`ere. Masson, 1994. N. Fressengeas Polarization Optics, version 2.0, frame 2 The physics of polarization optics Polarized light propagation Partially polarized light Course Outline 1 The physics of polarization optics Polarization states Jones Calculus Stokes parameters and the Poincare Sphere 2 Polarized light propagation Jones Matrices Examples Matrix, basis & eigen polarizations Jones Matrices Composition 3 Partially polarized light Formalisms used Propagation through optical devices N. Fressengeas Polarization Optics, version 2.0, frame 3 The physics of polarization optics Polarization states Polarized light propagation Jones Calculus Partially polarized light Stokes parameters and the Poincare Sphere The vector nature of light Optical wave can be polarized, sound waves cannot The scalar monochromatic plane wave The electric field reads: A cos (ωt kz ϕ) − − A vector monochromatic plane wave Electric field is orthogonal to wave and Poynting vectors -
Lab 8: Polarization of Light
Lab 8: Polarization of Light 1 Introduction Refer to Appendix D for photos of the appara- tus Polarization is a fundamental property of light and a very important concept of physical optics. Not all sources of light are polarized; for instance, light from an ordinary light bulb is not polarized. In addition to unpolarized light, there is partially polarized light and totally polarized light. Light from a rainbow, reflected sunlight, and coherent laser light are examples of po- larized light. There are three di®erent types of po- larization states: linear, circular and elliptical. Each of these commonly encountered states is characterized Figure 1: (a)Oscillation of E vector, (b)An electromagnetic by a di®ering motion of the electric ¯eld vector with ¯eld. respect to the direction of propagation of the light wave. It is useful to be able to di®erentiate between 2 Background the di®erent types of polarization. Some common de- vices for measuring polarization are linear polarizers and retarders. Polaroid sunglasses are examples of po- Light is a transverse electromagnetic wave. Its prop- larizers. They block certain radiations such as glare agation can therefore be explained by recalling the from reflected sunlight. Polarizers are useful in ob- properties of transverse waves. Picture a transverse taining and analyzing linear polarization. Retarders wave as traced by a point that oscillates sinusoidally (also called wave plates) can alter the type of polar- in a plane, such that the direction of oscillation is ization and/or rotate its direction. They are used in perpendicular to the direction of propagation of the controlling and analyzing polarization states. -
Polarization of EM Waves
Light in different media A short review • Reflection of light: Angle of incidence = Angle of reflection • Refraction of light: Snell’s law Refraction of light • Total internal reflection For some critical angle light beam will be reflected: 1 n2 c sin n1 For some critical angle light beam will be reflected: Optical fibers Optical elements Mirrors i = p flat concave convex 1 1 1 p i f Summary • Real image can be projected on a screen • Virtual image exists only for observer • Plane mirror is a flat reflecting surface Plane Mirror: ip • Convex mirrors make objects smaller • Concave mirrors make objects larger 1 Spherical Mirror: fr 2 Geometrical Optics • “Geometrical” optics (rough approximation): light rays (“particles”) that travel in straight lines. • “Physical” Classical optics (good approximation): electromagnetic waves which have amplitude and phase that can change. • Quantum Optics (exact): Light is BOTH a particle (photon) and a wave: wave-particle duality. Refraction For y = 0 the same for all x, t Refraction Polarization Polarization By Reflection Different polarization of light get reflected and refracted with different amplitudes (“birefringence”). At one particular angle, the parallel polarization is NOT reflected at all! o This is the “Brewster angle” B, and B + r = 90 . (Absorption) o n1 sin n2 sin(90 ) n2 cos n2 tan Polarizing Sunglasses n1 Polarized Sunglasses B Linear polarization Ey Asin(2x / t) Vertically (y axis) polarized wave having an amplitude A, a wavelength of and an angular velocity (frequency * 2) of , propagating along the x axis. Linear polarization Vertical Ey Asin(2x / t) Horizontal Ez Asin(2x / t) Linear polarization • superposition of two waves that have the same amplitude and wavelength, • are polarized in two perpendicular planes and oscillate in the same phase. -
Polarization (Waves)
Polarization (waves) Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations.[1][2][3][4][5] In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave.[4] A simple example of a polarized transverse wave is vibrations traveling along a taut string (see image); for example, in a musical instrument like a guitar string. Depending on how the string is plucked, the vibrations can be in a vertical direction, horizontal direction, or at any angle perpendicular to the string. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagation, so these waves do not exhibit polarization. Transverse waves that exhibit polarization include electromagnetic [6] waves such as light and radio waves, gravitational waves, and transverse Circular polarization on rubber sound waves (shear waves) in solids. thread, converted to linear polarization An electromagnetic wave such as light consists of a coupled oscillating electric field and magnetic field which are always perpendicular; by convention, the "polarization" of electromagnetic waves refers to the direction of the electric field. In linear polarization, the fields oscillate in a single direction. In circular or elliptical polarization, the fields rotate at a constant rate in a plane as the wave travels. The rotation can have two possible directions; if the fields rotate in a right hand sense with respect to the direction of wave travel, it is called right circular polarization, while if the fields rotate in a left hand sense, it is called left circular polarization. -
Lecture 14: Polarization
Matthew Schwartz Lecture 14: Polarization 1 Polarization vectors In the last lecture, we showed that Maxwell’s equations admit plane wave solutions ~ · − ~ · − E~ = E~ ei k x~ ωt , B~ = B~ ei k x~ ωt (1) 0 0 ~ ~ Here, E0 and B0 are called the polarization vectors for the electric and magnetic fields. These are complex 3 dimensional vectors. The wavevector ~k and angular frequency ω are real and in the vacuum are related by ω = c ~k . This relation implies that electromagnetic waves are disper- sionless with velocity c: the speed of light. In materials, like a prism, light can have dispersion. We will come to this later. In addition, we found that for plane waves 1 B~ = ~k × E~ (2) 0 ω 0 This equation implies that the magnetic field in a plane wave is completely determined by the electric field. In particular, it implies that their magnitudes are related by ~ ~ E0 = c B0 (3) and that ~ ~ ~ ~ ~ ~ k · E0 =0, k · B0 =0, E0 · B0 =0 (4) In other words, the polarization vector of the electric field, the polarization vector of the mag- netic field, and the direction ~k that the plane wave is propagating are all orthogonal. To see how much freedom there is left in the plane wave, it’s helpful to choose coordinates. We can always define the zˆ direction as where ~k points. When we put a hat on a vector, it means the unit vector pointing in that direction, that is zˆ=(0, 0, 1). Thus the electric field has the form iω z −t E~ E~ e c = 0 (5) ~ ~ which moves in the z direction at the speed of light. -
Polarization of Light Demonstration This Demonstration Explains Transverse Waves and Some Surprising Properties of Polarizers
Polarization of Light Demonstration This demonstration explains transverse waves and some surprising properties of polarizers. Number of Participants: Unlimited Audience: Middle (ages 11-13) and up Duration: 5-10 min Microbehunter Difficulty: Level 1 Materials Required: • 3 sheets of polarizing film – at least (20mm)2 • Long spring or Slinky Setup: 1. If necessary, prepare polarizing sheets by cutting a larger sheet into smaller pieces. While larger pieces of polarizing material are preferred, the demonstration works with smaller pieces. Presenter Brief: Light is a transverse wave because its two components, electric and magnetic fields, oscillate perpendicular to the direction of propagation. In general, a beam of light will consist of many photons traveling in the same direction but with arbitrary alignment of their electric and magnetic fields. Specifically, for an unpolarized light beam the electromagnetic components of each photon, while confined to a plane, are not aligned. If light is polarized, photons have aligned electromagnetic components and travel in the same direction. Polarization of Light Vocabulary: • Light – Electromagnetic radiation, which can be in the visible range. • Electromagnetic – A transverse wave consisting of oscillating electric and magnetic components. • Transverse wave – A wave consisting of oscillations perpendicular to the direction of propagation. • Polarized light – A beam of photons propagating with aligned oscillating components.Polarizer – A material which filters homogenous light along a singular axis and thus blocks arbitrary orientations and allows a specific orientation of oscillations. Physics & Explanation: Middle (ages 11-13) and general public: Light, or an electromagnetic wave, is a transverse wave with oscillating electric and magnetic components. Recall that in a transverse wave, the vibrations,” or oscillations, are perpendicular to the direction of propagation. -
Glossary of Terms Used in Photochemistry, 3Rd Edition (IUPAC
Pure Appl. Chem., Vol. 79, No. 3, pp. 293–465, 2007. doi:10.1351/pac200779030293 © 2007 IUPAC INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY ORGANIC AND BIOMOLECULAR CHEMISTRY DIVISION* SUBCOMMITTEE ON PHOTOCHEMISTRY GLOSSARY OF TERMS USED IN PHOTOCHEMISTRY 3rd EDITION (IUPAC Recommendations 2006) Prepared for publication by S. E. BRASLAVSKY‡ Max-Planck-Institut für Bioanorganische Chemie, Postfach 10 13 65, 45413 Mülheim an der Ruhr, Germany *Membership of the Organic and Biomolecular Chemistry Division Committee during the preparation of this re- port (2003–2006) was as follows: President: T. T. Tidwell (1998–2003), M. Isobe (2002–2005); Vice President: D. StC. Black (1996–2003), V. T. Ivanov (1996–2005); Secretary: G. M. Blackburn (2002–2005); Past President: T. Norin (1996–2003), T. T. Tidwell (1998–2005) (initial date indicates first time elected as Division member). The list of the other Division members can be found in <http://www.iupac.org/divisions/III/members.html>. Membership of the Subcommittee on Photochemistry (2003–2005) was as follows: S. E. Braslavsky (Germany, Chairperson), A. U. Acuña (Spain), T. D. Z. Atvars (Brazil), C. Bohne (Canada), R. Bonneau (France), A. M. Braun (Germany), A. Chibisov (Russia), K. Ghiggino (Australia), A. Kutateladze (USA), H. Lemmetyinen (Finland), M. Litter (Argentina), H. Miyasaka (Japan), M. Olivucci (Italy), D. Phillips (UK), R. O. Rahn (USA), E. San Román (Argentina), N. Serpone (Canada), M. Terazima (Japan). Contributors to the 3rd edition were: A. U. Acuña, W. Adam, F. Amat, D. Armesto, T. D. Z. Atvars, A. Bard, E. Bill, L. O. Björn, C. Bohne, J. Bolton, R. Bonneau, H. -
Chapter 9 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 of refraction for light. Refraction, total internal reflection and the polarization of light reflecting from a nonmetallic surface will be investigated 9.2 Introduction Light can travel through many transparent media such as water, glass and air. When this happens the speed of light is no longer c =3 108 m/s (the speed in vacuum), but is less. This reduction in the speed depends on the material.⇥ This change in speed and direction is called refraction and is governed by Snell’s Law of Refraction. n1sin✓1 = n2sin✓2 (9.1) The ratio of the speed of light in vacuum to that in the medium is called the index of refraction (n). The index of refraction is a number greater than or equal to one. The angles (✓1 and ✓2)aremeasuredwithrespecttothenormal(perpendicular)totheinterfacebetween the two media (See Figure 9.1). When light passes from a medium of higher index of refraction to a medium with a lower index of refraction, the light ray can be refracted at 900.Thisphenomenoniscalledtotal internal reflection.Forincidentanglesgreaterthan✓c,thereisnorefractedbeam.The transmission of light by fiber-optic cable uses this e↵ect. The critical angle of incidence where total internal reflection occurs is given by: n2 sin✓c = n1 >n2 (9.2) n1 If this angle and the index of refraction of one of the two media is known, the index of refraction of the other medium can be found. -
Understanding Polarization
Semrock Technical Note Series: Understanding Polarization The Standard in Optical Filters for Biotech & Analytical Instrumentation Understanding Polarization 1. Introduction Polarization is a fundamental property of light. While many optical applications are based on systems that are “blind” to polarization, a very large number are not. Some applications rely directly on polarization as a key measurement variable, such as those based on how much an object depolarizes or rotates a polarized probe beam. For other applications, variations due to polarization are a source of noise, and thus throughout the system light must maintain a fixed state of polarization – or remain completely depolarized – to eliminate these variations. And for applications based on interference of non-parallel light beams, polarization greatly impacts contrast. As a result, for a large number of applications control of polarization is just as critical as control of ray propagation, diffraction, or the spectrum of the light. Yet despite its importance, polarization is often considered a more esoteric property of light that is not so well understood. In this article our aim is to answer some basic questions about the polarization of light, including: what polarization is and how it is described, how it is controlled by optical components, and when it matters in optical systems. 2. A description of the polarization of light To understand the polarization of light, we must first recognize that light can be described as a classical wave. The most basic parameters that describe any wave are the amplitude and the wavelength. For example, the amplitude of a wave represents the longitudinal displacement of air molecules for a sound wave traveling through the air, or the transverse displacement of a string or water molecules for a wave on a guitar string or on the surface of a pond, respectively. -
Physics 212 Lecture 24
Physics 212 Lecture 24 Electricity & Magnetism Lecture 24, Slide 1 Your Comments Why do we want to polarize light? What is polarized light used for? I feel like after the polarization lecture the Professor laughs and goes tell his friends, "I ran out of things to teach today so I made some stuff up and the students totally bought it." I really wish you would explain the new right hand rule. I cant make it work in my mind I can't wait to see what demos are going to happen in class!!! This topic looks like so much fun!!!! With E related to B by E=cB where c=(u0e0)^-0.5, does the ratio between E and B change when light passes through some material m for which em =/= e0? I feel like if specific examples of homework were done for us it would help more, instead of vague general explanations, which of course help with understanding the theory behind the material. THIS IS SO COOL! Could you explain what polarization looks like? The lines that are drawn through the polarizers symbolize what? Are they supposed to be slits in which light is let through? Real talk? The Law of Malus is the most metal name for a scientific concept ever devised. Just say it in a deep, commanding voice, "DESPAIR AT THE LAW OF MALUS." Awesome! Electricity & Magnetism Lecture 24, Slide 2 Linearly Polarized Light So far we have considered plane waves that look like this: From now on just draw E and remember that B is still there: Electricity & Magnetism Lecture 24, Slide 3 Linear Polarization “I was a bit confused by the introduction of the "e-hat" vector (as in its purpose/usefulness)” Electricity & Magnetism Lecture 24, Slide 4 Polarizer The molecular structure of a polarizer causes the component of the E field perpendicular to the Transmission Axis to be absorbed. -
Optical Rotation and Linear and Circular Depolarization Rates in Diffusively Scattered Light from Chiral, Racemic, and Achiral Turbid Media
Journal of Biomedical Optics 7(3), 291–299 (July 2002) Optical rotation and linear and circular depolarization rates in diffusively scattered light from chiral, racemic, and achiral turbid media Kevin C. Hadley Abstract. The polarization properties of light scattered in a lateral University of Waterloo direction from turbid media were studied. Polarization modulation Department of Chemistry and synchronous detection were used to measure, and Mueller calcu- Waterloo, Ontario N2L 3G1, Canada lus to model and derive, the degrees of surviving linear and circular I. Alex Vitkin polarization and the optical rotation induced by turbid samples. Poly- Ontario Cancer Institute/University of Toronto styrene microspheres were used as scatterers in water solutions con- Departments of Medical Biophysics and taining dissolved chiral, racemic, and achiral molecules. The preser- Radiation Oncology vation of circular polarization was found to exceed the linear Toronto, Ontario M5G 2M9, Canada polarization preservation for all samples examined. The optical rota- tion induced increased with the chiral molecule concentration only, whereas both linear and circular polarizations increased with an in- crease in the concentrations of chiral, racemic, and achiral molecules. This latter effect was shown to stem solely from the refractive index matching mechanism induced by the solute molecules, independent of their chiral nature. © 2002 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.1483880] Keywords: polarization; multiple scattering; chirality; polarization modulation. Paper JBO TP-14 received Mar. 8, 2002; revised manuscript received Mar. 14, 2002; accepted for publication Mar. 31, 2002. 1 Introduction Optical investigations of turbid media that contain chiral 23–31 Many natural and synthetic systems have disordered proper- components have also been reported. -
Circular Polarization of Fluorescence of Probes Bound to Chymotrypsin
Proc. Nat. ASad. Sci. USA Vol. 69, No. 3, pp. 769-772, March 1972 Circular Polarization of Fluorescence of Probes Bound to Chymotrypsin. Change in Asymmetric Environment upon Electronic Excitation* (circularly polarized luminescence/proteins/fluoresent probes) JOSEPH SCHLESSINGERt AND IZCHAK Z. STEINBERG Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel Communicated by Harold A. Scheraga, January 13, 197S ABSTRACT The circular polarization of fluorescence excited. The site, strength, rigidity, and geometry of binding is related to the conformational asymmetry of the emitting of a fluorescent probe to a protein molecule may thus molecule in the first singlet excited state in the same way differ that circular dichroism is related to the conformational in the ground and excited states. The use of fluorescence asymmetry of the absorbing molecule in the electronic for the study of the binding and the environment of the ground state. By measurement of these optical pheno- chromophore in the ground state, therefore, involves the mena, the induced asymmetry of two chromophores bound basic assumption that in the case under investigation no to chymotrypsin (EC 3.4.4.5) when in the ground state Was compared with the induced asymmetry of the ligands major changes have occurred in the bound chromophore when in the excited state. The two chromophores studied upon electronic excitation. Detection and examination of such were 2-p-toluidinylnaphthalene-6.sulfonate (TNS), bound changes is therefore of much interest and importance. at a specific site which is not the active site of the protein, In this study, the changes in the interaction of a protein and an anthraniloyl group, bound at the active site of the molecule and an attached extrinsic chromophore caused by enzyme.