The moct measures the electric current by means of faraday effect. The research activities on the phenomenon of magneto optic effects has recently promulgated due to its versatile use in magneto optic recordings for high density magnetic data storage, magnetic field sensors and its applications in magnetoelectronics. The theory of the linear electro optic effect in crystals such as zincblende zns, gaas and gap is described by sterzer, blattner, and miniter reference 2. Development of a surface magneto optic kerr effect magnetometer susan stoffer sorensen a senior thesis submitted to the faculty of brigham young university in partial fulfillment of the requirements for the degree of bachelor of science dr. The dependence of the refractive index on the applied electric field takes one of two forms. The theory of the linear electrooptic effect in crystals such as zincblende zns, gaas and gap is. The optic axis of this induced optical activity is aligned with the axis of the applied magnetic field. The electrooptic effect is the phenomenon that the refractive index of a material can be modified with an electric field. Magnetooptic effects in singlemode fibres eprints soton.
These two phenomena are conceptually very similar but differ mainly from their point of reference. It is shown that the effect polar magnetooptic effect is two order stronger than the equatorial. Magneto optic materials have unique physical properties that offer the opportunity of constructing devices with many special functions not possible from other photonic devices. Magnetooptic effect article about magnetooptic effect.
A magnetic field, like any vector field, singles out a specific direction in space. In contrast, the acoustooptic effect has had a relatively short history, beginning with brillouin predicting the diffraction of light by an acoustic wave, being propagated. Though both alloys have very similar electronic band structures, the moke spectra exhibit quite different features. The objective of this work was to measure the verdet constant for different transparent materials. The results of reflection from a magneto optic material are known as the magneto optic kerr effect not to be confused with the nonlinear kerr effect. The term encompasses a number of distinct phenomena, which can be subdivided into a change of the absorption. Control light with heat and magnets magnetooptical kerr. A novel sensor technique using a magnetic thin film as the sensing element and the magneto. Osa magnetooptic polar kerr and faraday effects in. Some practical applications of the faraday magnetooptic. Magnetism, light and the magneto optic kerr effect youtube. In a magneto optic material the situation is a bit different. It describes the changes to light reflected from a magnetized surface.
To scramble and unscramble transmitted messages, an optical communication system was designed and effectively tested. Detailed studies have been made of the magnetooptic effect in singlemode fibres exhibiting both linear and circular retardations. Linear electrooptic effects due to high order spatial dispersion. Development of a surface magnetooptic kerr effect magnetometer. Finally the concept of magneto optic kerr effect is discussed and a setup utilizing the effect for magnetic probing is presented. An electrooptic effect is a change in the optical properties of a material in response to an. Kerr electro optic effect, in physics, the inducement of double refraction of light in a transparent substance when a strong electric field is applied in a direction transverse to the beam of light. The photomagnetic and magnetooptic effects springerlink. Magneto optic effect synonyms, magneto optic effect pronunciation, magneto optic effect translation, english dictionary definition of magneto optic effect. An introduction to acoustooptics scott e pollack physics 7810 fundamentals of optics and lasers university of colorado, boulder december, 2002 abstract this paper is a brief introduction to acoustooptic phenomena.
Magnetooptic effect article about magnetooptic effect by. In addition, some work was done to grow ktn crystals, but the results as yet are inconclusive. Thermooptic effect exploitation in silicon microstructures. Aug 10, 2015 learn how magneto optical storage discs work, and see how a focused laser can directly alter a materials optical characteristics. A novel technique enables the verdet constant to be easily measured. A novel sensor technique using a magnetic thin film as the sensing element and the magneto optic kerr effect as the optical read technique has been tested experimentally through magnetic field measurements. Some practical applications of the faraday magnetooptic effect, the kerr electrooptic effect, and the pockels electrooptic effect in the early decades of the 20th century. Magneto optical kerr e ect moke photonphoton spectroscopies absorption ii. All practical magnetooptic devices exploit one or both of these two properties. There is currently great interest in the magnetic and magnetooptical. Recent advances towards electrooptic eo modulators make use of the pockels effect in noncentrosymmetric crystals which allows the.
Magnetooptic kerr effect is a property of light where light is reflected off a strongly. The most significant of these properties are that the linear magnetooptic effect can produce circular birefringence and that, unlike other optical effects in dielectric media, it is nonreciprocal. Optics has had a very long and full history, from ancient greece, through the renaissance and modern times. Development of a surface magnetooptic kerr effect magnetometer susan stoffer sorensen a senior thesis submitted to the faculty of brigham young university in partial fulfillment of the requirements for the degree of bachelor of science dr. The program was a parallel effort on gaas and gap electro optic crystals. When light is transmitted through a layer of magneto optic material, the result is called the faraday effect. Magnetism, light and the magneto optic kerr effect joseph copland. This was then confirmed with experimentation in 1932 by debye and sears, and also by lucas and biquard. Both magnetic circularlinear birefringence and dichroism, and void and cottonmouton effects are discussed. Theoretical study of electrooptic effect and elastooptic. In physics the magneto optic kerr effect moke or the surface magneto optic kerr effect smoke is one of the magneto optic effects. Di erent energy ranges probes di erent part of the electronic structure of the matter. In the linear electrooptic effect, the size of the perturbation to the refractive index is directly proportional to the strength of the.
The magneto optic effects and electro optic effects are the essential optic effects, although their theoretical explanations are not unified in the classical electromagnetic theory. An electrooptic effect is a change in the optical properties of a material in response to an electric field that varies slowly compared with the frequency of light. In double refraction, the index of refraction a measure of the amount the ray is bent on entering. This effect can cause losses due to frictional heating. It is desired to adapt the surface magneto optic kerr effect setup to an existing vacuum system already containing a vaporizer, mass spectrometers, leed, and a stm. Magnetooptic effect definition of magnetooptic effect. Propagation of weak optic signals in strong quasistatic fields description using renormalized linear parameters. Magnetooptical kerr e ect moke photonphoton spectroscopies absorption ii. The term encompasses a number of distinct phenomena, which can be subdivided into. Magnetooptics article about magnetooptics by the free. The magnetooptic effects and electrooptic effects are the essential optic effects, although their theoretical explanations are not unified in the classical electromagnetic theory. The faraday and kerr effects associated with a transition between the ground state and excited state. Longitudinal magnetooptic kerr effect system microsense.
That branch of physics which deals with the influence of a magnetic field on optical phenomena. Magnetooptic kerr effect sensors for fiber optic applications. A pictorial representation of magneto optic effect. A temperature sensor, an electromagnetic energy sensor and an optical modulator are in particular presented. The electrooptic effect is the phenomenon that the refractive index of a material can be modified with an. The strong thermooptic effect in silicon has been exploited for the fabrication of new sensing and communication devices. Two new types of electrooptic effect that are linear in the applied electric field strength are theoretically predicted to exist in. Magnetooptic effect synonyms, magnetooptic effect pronunciation, magnetooptic effect translation, english dictionary definition of magnetooptic effect. The electrooptic effect manifests itself as a change in the refractive index of a medium to which a static or a low frequency electric field is applied. The source of this optical anisotropy is the magnetisation m within surface domains which can be influenced. Magneto optic effect is a phenomenon in which an electromagnetic wave propagates through a medium and gets affected by the presence of a quasistatic magnetic field.
This chapter will discuss the theory and applications of the photomagnetic and magnetoptic effects. In physics the magnetooptic kerr effect moke or the surface magnetooptic kerr effect smoke is one of the magnetooptic effects. Finally the concept of magnetooptic kerr effect is discussed and a setup utilizing the effect for magnetic probing is presented. It used the improved faraday effect at low fields to produce polarization. The most significant of these properties are that the linear magneto optic effect can produce circular birefringence and. Measurement of magnetooptic kerr effect using piezobirefringent modulator j. Lbnl42066 preprint 102998 1 nonlinear magnetooptic effects with ultranarrow widths dmitry budker a,b, valeriy yashchuk a,c, and max zolotorev b a department of physics, university of california, berkeley, california 947207300 b e. Reflection and absorption mode devices using magneto optic effects seem to be too small to be of interest. Fundamental optical and magnetooptical constants of copt and. A magnetooptic effect is any one of a number of phenomena in which an electromagnetic wave propagates through a medium that has been altered by the presence of a quasistatic magnetic field. First, we will explain the theoretical background of magneto optic effects from both macroscopic and microscopic points of view. Lawrence berkeley national laboratory, berkeley, california 94720 c b.
The program was a parallel effort on gaas and gap electrooptic crystals. Densityfunctional theory calculations on the magneto. In such a material, which is also called gyrotropic or gyromagnetic, left and rightrotating elliptical polarizations can propagate at different speeds, leading to a. Applications of the effect, together with the magnitude of electromagnetic interference in optical fibres likely to be encountered in practice, are discussed. Detailed studies have been made of the magneto optic effect in singlemode fibres exhibiting both linear and circular retardations. Considering the fact that light is electromagnetic.
The source of this optical anisotropy is the magnetisation m within surface domains which can be influenced by external forces such as magnetic fields. The effect was first identified in 1842 by james joule when observing a sample of nickel. R r ss r sp r ps r pp re ection matrix is the only quantity accessible for sample investigations by optical means. We present to the reader the mathematical formalism used to describe this phenomena as well as the common. Longitudinal magnetooptic kerr effect system kerrmapper s300 and v300. This chapter will discuss the theory and applications of the photomagnetic and magnet optic effects. Control light with heat and magnets magnetooptical kerr effect. The research activities on the phenomenon of magneto optic effects has recently promulgated due to its versatile use in magneto optic recordings for high density magnetic data storage, magnetic field sensors and its applications in magneto electronics. In contrast, the acousto optic effect has had a relatively short history, beginning with brillouin predicting the diffraction of light by an acoustic wave, being propagated in a medium of interaction, in 1922. Verdet constant describes the strength of faraday effect for a particular material.
Rp photonics encyclopedia electrooptic effect, pockels. A surprisingly large magnetooptical response occurs when mobile electrons in a cooled material become trapped by their interaction with the surrounding lattice. In a magnetooptic material the situation is a bit different. Acoustooptics is a phenomenon which deals with the interaction of light optics and sound acoustics. Karine chesnel, advisor department of physics and astronomy brigham young university december 20. Cotton mouton effect birefringence effect signal proportional to m. Magnetooptical devices the optics encyclopedia castera.
This seminar discusses magneto optic effects, phenomena in which optical properties of a medium and therefore its interaction with light are dependent on a magnetic field. The electro optic effect is the phenomenon that the refractive index of a material can be modified with an electric field. Nonlinear magnetooptic effects with ultranarrow widths. The electrooptic effect is the modification of the refractive index by an externally applied electrostatic field. The branch of physics that deals with phenomena associated with magnetic effects on matter as it emits light, having applications in computer. The discovery of magneto optical effects evoked a new thought that the nature of light was an electromagnetic entity, and played a central role. Giant electrooptic effect using polarizable dark states. Magneto optical kerr e ect moke optics of multilayers i total optical response of multilayer described by re ection matrix.
Konstantinov petersburg nuclear physics institute, gatchina, russia 188350. An electro optic effect is a change in the optical properties of a material in response to an electric field that varies slowly compared with the frequency of light. Acoustooptical effects principles and applications. It is used in materials science research in devices such as the kerr microscope, to investigate the magnetization structure of materials. The discovery of magnetooptical effects evoked a new thought that the nature of light was an electromagnetic entity, and played a central role.
Faraday effect and other magnetooptic effects in semiconductors. Conventional current transformers becomes more and more bulky and costly. Reis focus center and department of physics, university. In such a medium, which is also called gyrotropic or gyromagnetic, left and rightrotating elliptical polarizations can propagate at different speeds, leading to a number of important phenomena. The physical origin of the magnetooptical effects is phenomenologically discussed. Study of birefringence and electrooptic effect in sbn60 thin film. Magnetooptic mo effects in magnetic multilayers with periodically stratified regions are analyzed for the case of normal light wave incidence and polar magnetization faraday and polar kerr effects. A magnetooptic effect is any one of a number of phenomena in which an electromagnetic. Magneto optic current transducer consist of a sensor head located near the current carrying conductor, an electronic signal processing unit and fiber optical cables linking to these two parts. A chirped fiber grating with cladding made of uniaxial crystal material whose optical axis is parallel to the axis of grating, i.
Magnetooptics a branch of physics that studies changes in the optical properties of media upon exposure to a magnetic field and the peculiarities of the interaction of optical radiation light with matter placed in the field that are responsible for the changes. Magnitude and nature of the quadratic electro optic effect in. Kerr electrooptic effect, in physics, the inducement of double refraction of light in a transparent substance when a strong electric field is applied in a direction transverse to the beam of light. Leo kristjansson, april 2017 research on very rapid processes let a beam of ordinary light pass through a polarizing nicol prism and a glass vessel. One of the main challenges of using silicon as an active photonic material is its low electrooptic coefficient. Electro optic effect and elasto optic effect in this kind of fiber gratings are theoretically analyzed for the first time. As with optics, acoustics has a history of similar duration, again starting with the ancient greeks.
The kerrmapper family of tools utilizes the longitudinal magnetooptical kerr effect moke to characterize the magnetic properties of magnetic multilayer wafers for data storage, mram, and other magnetic sensors. Electrooptic modulator based on machzehnder interferometer electrooptic effect, n 2 changes with e field, n 2 n 1. Pdf faraday effect and other magnetooptic effects in. Faraday effect, as well as to both classical and quantum theory of matter including the motions of electron. The existence of an interaction between light and sound was discovered by brillouin in the. Some practical applications of the faraday magneto optic effect, the kerr electro optic effect, and the pockels electro optic effect in the early decades of the 20th century. Electrooptic effect, n changes with e field, n n 1. Learn how magnetooptical storage discs work, and see how a focused laser can directly alter a materials optical characteristics. The linearly polarized wave can be seen as a superposition of the two above mentioned circularly polarized components, lcp and rcp. It is desired to adapt the surface magnetooptic kerr effect setup to an existing vacuum system already containing a vaporizer, mass spectrometers, leed, and a stm. The faraday and kerr effects zoe little, klaudia kozek, and.
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