The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Martin M. Fejer - One of the best experts on this subject based on the ideXlab platform.
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High-resolution magneto-optic measurements with a Sagnac interferometer (invited) Magnetic Imaging and Measuring Techniques High-resolution magneto-optic measurements with a Sagnac interferometer (invited)
Journal of Applied Physics Applied Physics Letters, 1994Co-Authors: Aharon Kapitulnik, J. S. Dodge, Roger Proksch, Martin M. Fejer, J FlorczakAbstract:Articles you may be interested in Modified Sagnac interferometer for high-sensitivity magneto-optic measurements at cryogenic temperatures Applied Physics Letters 89, 062508 (2006); 10.1063/1.2336620 A scanning, all-fiber Sagnac interferometer for high resolution magneto-optic measurements at 820 nm Review of Scientific Instruments 85, 103707 (2014); 10.1063/1.4897184 Surface magneto-optic Kerr effect Review of Scientific Instruments 71, 1243 (2000); 10.1063/1.1150496 Polarizers, optical bridges, and Sagnac interferometers for nanoradian polarization rotation measurements Review of Scientific Instruments 88, 043903 (2017); 10.1063/1.4980038 Zero loop-area Sagnac interferometer at oblique-incidence for detecting in-plane magneto-optic Kerr effect AIP Advances 7, 055008 (2017); 10.1063/1.4983802 In situ near-field imaging of magnetic domain patterns in ultrathin iron films A technique for measuring the Faraday effect and the magneto-optic Kerr effect has been developed. In a Sagnac interferometer, two optical beams follow identical paths in opposite directions. Effects which break time-reversal symmetry, such as magneto-optic effects, will cause destructive interference between the two beams. By measuring the phase shift between circular polarization states reflected from a magnetized sample, the polar magneto-optic Kerr effect is measured to an accuracy of 3 prad, with a spatial resolution of 2 pm. The interferometric technique provides a number of advantages over conventional polarizer methods, including insensitivity to linear birefringence, the ability to completely determine the magnetization vector in a region, and the ability to sensitively measure magneto-optic effects without an external field. It is also shown that this device has great potential if incorporated into a near-field optical device. Some of the considerations for the design of a near-field Sagnac magneto-optic sensor are introduced and the advantages of the device are discussed. Some preliminary experiments are shown.
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High-resolution magneto-optic measurements with a Sagnac interferometer (invited)
Journal of Applied Physics, 1994Co-Authors: Aharon Kapitulnik, J. S. Dodge, Martin M. FejerAbstract:A technique for measuring the Faraday effect and the magneto‐optic Kerr effect has been developed. In a Sagnac interferometer, two optical beams follow identical paths in opposite directions. Effects which break time‐reversal symmetry, such as magneto‐optic effects, will cause destructive interference between the two beams. By measuring the phase shift between circular polarization states reflected from a magnetized sample, the polar magneto‐optic Kerr effect is measured to an accuracy of 3 μrad, with a spatial resolution of 2 μm. The interferometric technique provides a number of advantages over conventional polarizer methods, including insensitivity to linear birefringence, the ability to completely determine the magnetization vector in a region, and the ability to sensitively measure magneto‐optic effects without an external field. It is also shown that this device has great potential if incorporated into a near‐field optical device. Some of the considerations for the design of a near‐field Sagnac magneto‐optic sensor are introduced and the advantages of the device are discussed. Some preliminary experiments are shown.
S. D. Bader - One of the best experts on this subject based on the ideXlab platform.
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surface magneto optic kerr effect
Characterization of Materials, 2012Co-Authors: S. D. BaderAbstract:In 1845, Michael Faraday found that the polarization plane of linearly polarized light rotates as the light is transmitted through a magnetized medium. Thirty-two years later the magneto-optic Kerr effect (MOKE) was discovered by John Kerr when he examined the polarization of light reflected from the polished surface of an electromagnet. These two monumental works heralded the beginnings of Magneto-Optics and form the foundation of its modern utilization. As the field of surface and thin-film magnetism has emerged and blossomed in recent years, so has the need for innovative approaches to study magnetic phenomena on the nanometer-thickness scale. The application of the Kerr effect to study the surface magnetism was introduced by Moog and Bader (1985) along with the acronym SMOKE to denote the surface magneto-optic Kerr effect. Since then SMOKE has emerged as a premier surface magnetism technique of choice in many laboratories worldwide. The broad acceptance of the SMOKE technique stems from its simplicity and its ability to generate the “universal currency” in magnetism—the hysteresis loop. In addition, there are almost no materials limitations to this technique, as long as the sample surface is smooth enough to generate optical reflection. However, the magnitude of the SMOKE signal depends on the materials properties and on the optical wavelength. Although in this article the SMOKE technique for visible light with fixed wavelength is described, it is easy to extend the technique to wavelength-dependent measurements such as magneto-optic spectroscopy and spatially resolved measurements such as magneto-optic microscopy. Nevertheless, SMOKE has been applied successfully to address various contemporary topics in low-dimensional magnetism. The aim of this article is to provide general background about the basic principles and experimental methods of the SMOKE technique. While much of the discussion is directed to nonspecialists, it is structured with the inclusion of mathematical exposition to describe Magneto-Optics of magnetic multilayers. There are many challenges left to overcome in the quest to provide a complete magnetic characterization of ultrathin-film structures. Significant progress has been made recently to develop second-harmonic-generation (SHG) MOKE to distinguish the response of the surface and/or interfacial layer from the interior-layer or bulk response. A future direction could involve the combination of SMOKE with other techniques to enhance both spatial and time resolution so that small-scale processes, such as domain wall dynamics, can be investigated. The purpose of this article is to provide background on the SMOKE technique with an emphasis on magnetic multilayers. As described in the next section, the magneto-optic effect originates from the spin-orbit interaction. Therefore SMOKE should be regarded as one of many possible versions of this interaction. Others include the Faraday effect technique, which is usually applied to optically transparent materials, and core-level magnetic dichroism, which is an element-specific measurement. Keywords: magneto-optic; quantum description; ferromagnet; kerr effect; practical aspects; method automation; cobalt/copper lattices; ultrathin limit; medium boundary matrices; medium propagation matrices
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Surface magneto-optic Kerr effect (SMOKE)
Journal of Magnetism and Magnetic Materials, 1999Co-Authors: Z. Q. Qiu, S. D. BaderAbstract:The purpose of this article is to stimulate interest in the power of the surface magneto-optic Kerr effect (SMOKE) technique to address a range of contemporary issues associated with the physics of interfacial magnetic materials. Magneto-Optics is introduced from both historical and modern perspectives. Experimental considerations are briefly considered. Topics highlighted include the phases of face-centered Fe, the phenomenon of oscillatory magnetic coupling, the two-dimensional spin-reorientation transition, step-induced magnetic anistropies in FCC and BCC systems, and spin frustration at the interface between ferromagnetic and antiferromagnetic films.
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Second-order magneto-optic effects in anisotropic thin films
Journal of Magnetism and Magnetic Materials, 1998Co-Authors: R.m Osgood Iii, Bruce M. Clemens, S. D. Bader, R.l. White, Hiroyuki MatsuyamaAbstract:For films with in-plane anisotropy, second-order magneto-optic effects proportional to the square of the spin–orbit interaction can manifest themselves. We report typical measurements of the second-order magneto-optic Kerr effect in Fe, Co, and NiFe thin films with in-plane anisotropy and compare to theoretical predictions based on an interband transition model. We conclude that intraband transitions must play a role at 1.96eV. The second-order magneto-optic effects provide interesting insights into the magnetization reversal process, and also describe the dielectric tensor of a ferromagnetic metal. Furthermore, since the second-order magneto-optic effect is connected with the asymmetry of the magneto-optic hysteresis loop, which arises as a result of the coherent rotation of the magnetization vector, we interpret such asymmetries, which have been previously reported in the literature.
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Universal approach to Magneto-Optics
Journal of Magnetism and Magnetic Materials, 1990Co-Authors: Jaroslav Žák, E. R. Moog, Chunyuan Liu, S. D. BaderAbstract:Magneto-Optics is described in a unique framework. Reflection and transmission of a general multilayer system is expressed by means of medium boundary and propagation matrices which are universal and apply to any configuration of films and media. The results for the magneto-optic coefficients are cast in the form of sets of four linear, inhomogeneous equations. It is shown that in the thin-film limit, the Kerr effect obeys an additivity law for a system consisting of any number of magnetic films. Computer simulations were performed on different film-configurations, including an overlayer, a sandwich and a superlattice. © 1990.
Aharon Kapitulnik - One of the best experts on this subject based on the ideXlab platform.
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High-resolution magneto-optic measurements with a Sagnac interferometer (invited) Magnetic Imaging and Measuring Techniques High-resolution magneto-optic measurements with a Sagnac interferometer (invited)
Journal of Applied Physics Applied Physics Letters, 1994Co-Authors: Aharon Kapitulnik, J. S. Dodge, Roger Proksch, Martin M. Fejer, J FlorczakAbstract:Articles you may be interested in Modified Sagnac interferometer for high-sensitivity magneto-optic measurements at cryogenic temperatures Applied Physics Letters 89, 062508 (2006); 10.1063/1.2336620 A scanning, all-fiber Sagnac interferometer for high resolution magneto-optic measurements at 820 nm Review of Scientific Instruments 85, 103707 (2014); 10.1063/1.4897184 Surface magneto-optic Kerr effect Review of Scientific Instruments 71, 1243 (2000); 10.1063/1.1150496 Polarizers, optical bridges, and Sagnac interferometers for nanoradian polarization rotation measurements Review of Scientific Instruments 88, 043903 (2017); 10.1063/1.4980038 Zero loop-area Sagnac interferometer at oblique-incidence for detecting in-plane magneto-optic Kerr effect AIP Advances 7, 055008 (2017); 10.1063/1.4983802 In situ near-field imaging of magnetic domain patterns in ultrathin iron films A technique for measuring the Faraday effect and the magneto-optic Kerr effect has been developed. In a Sagnac interferometer, two optical beams follow identical paths in opposite directions. Effects which break time-reversal symmetry, such as magneto-optic effects, will cause destructive interference between the two beams. By measuring the phase shift between circular polarization states reflected from a magnetized sample, the polar magneto-optic Kerr effect is measured to an accuracy of 3 prad, with a spatial resolution of 2 pm. The interferometric technique provides a number of advantages over conventional polarizer methods, including insensitivity to linear birefringence, the ability to completely determine the magnetization vector in a region, and the ability to sensitively measure magneto-optic effects without an external field. It is also shown that this device has great potential if incorporated into a near-field optical device. Some of the considerations for the design of a near-field Sagnac magneto-optic sensor are introduced and the advantages of the device are discussed. Some preliminary experiments are shown.
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High-resolution magneto-optic measurements with a Sagnac interferometer (invited)
Journal of Applied Physics, 1994Co-Authors: Aharon Kapitulnik, J. S. Dodge, Martin M. FejerAbstract:A technique for measuring the Faraday effect and the magneto‐optic Kerr effect has been developed. In a Sagnac interferometer, two optical beams follow identical paths in opposite directions. Effects which break time‐reversal symmetry, such as magneto‐optic effects, will cause destructive interference between the two beams. By measuring the phase shift between circular polarization states reflected from a magnetized sample, the polar magneto‐optic Kerr effect is measured to an accuracy of 3 μrad, with a spatial resolution of 2 μm. The interferometric technique provides a number of advantages over conventional polarizer methods, including insensitivity to linear birefringence, the ability to completely determine the magnetization vector in a region, and the ability to sensitively measure magneto‐optic effects without an external field. It is also shown that this device has great potential if incorporated into a near‐field optical device. Some of the considerations for the design of a near‐field Sagnac magneto‐optic sensor are introduced and the advantages of the device are discussed. Some preliminary experiments are shown.
J. S. Dodge - One of the best experts on this subject based on the ideXlab platform.
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High-resolution magneto-optic measurements with a Sagnac interferometer (invited) Magnetic Imaging and Measuring Techniques High-resolution magneto-optic measurements with a Sagnac interferometer (invited)
Journal of Applied Physics Applied Physics Letters, 1994Co-Authors: Aharon Kapitulnik, J. S. Dodge, Roger Proksch, Martin M. Fejer, J FlorczakAbstract:Articles you may be interested in Modified Sagnac interferometer for high-sensitivity magneto-optic measurements at cryogenic temperatures Applied Physics Letters 89, 062508 (2006); 10.1063/1.2336620 A scanning, all-fiber Sagnac interferometer for high resolution magneto-optic measurements at 820 nm Review of Scientific Instruments 85, 103707 (2014); 10.1063/1.4897184 Surface magneto-optic Kerr effect Review of Scientific Instruments 71, 1243 (2000); 10.1063/1.1150496 Polarizers, optical bridges, and Sagnac interferometers for nanoradian polarization rotation measurements Review of Scientific Instruments 88, 043903 (2017); 10.1063/1.4980038 Zero loop-area Sagnac interferometer at oblique-incidence for detecting in-plane magneto-optic Kerr effect AIP Advances 7, 055008 (2017); 10.1063/1.4983802 In situ near-field imaging of magnetic domain patterns in ultrathin iron films A technique for measuring the Faraday effect and the magneto-optic Kerr effect has been developed. In a Sagnac interferometer, two optical beams follow identical paths in opposite directions. Effects which break time-reversal symmetry, such as magneto-optic effects, will cause destructive interference between the two beams. By measuring the phase shift between circular polarization states reflected from a magnetized sample, the polar magneto-optic Kerr effect is measured to an accuracy of 3 prad, with a spatial resolution of 2 pm. The interferometric technique provides a number of advantages over conventional polarizer methods, including insensitivity to linear birefringence, the ability to completely determine the magnetization vector in a region, and the ability to sensitively measure magneto-optic effects without an external field. It is also shown that this device has great potential if incorporated into a near-field optical device. Some of the considerations for the design of a near-field Sagnac magneto-optic sensor are introduced and the advantages of the device are discussed. Some preliminary experiments are shown.
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High-resolution magneto-optic measurements with a Sagnac interferometer (invited)
Journal of Applied Physics, 1994Co-Authors: Aharon Kapitulnik, J. S. Dodge, Martin M. FejerAbstract:A technique for measuring the Faraday effect and the magneto‐optic Kerr effect has been developed. In a Sagnac interferometer, two optical beams follow identical paths in opposite directions. Effects which break time‐reversal symmetry, such as magneto‐optic effects, will cause destructive interference between the two beams. By measuring the phase shift between circular polarization states reflected from a magnetized sample, the polar magneto‐optic Kerr effect is measured to an accuracy of 3 μrad, with a spatial resolution of 2 μm. The interferometric technique provides a number of advantages over conventional polarizer methods, including insensitivity to linear birefringence, the ability to completely determine the magnetization vector in a region, and the ability to sensitively measure magneto‐optic effects without an external field. It is also shown that this device has great potential if incorporated into a near‐field optical device. Some of the considerations for the design of a near‐field Sagnac magneto‐optic sensor are introduced and the advantages of the device are discussed. Some preliminary experiments are shown.
B M Clemens - One of the best experts on this subject based on the ideXlab platform.
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epitaxial ptfe 001 thin films on mgo 001 with perpendicular magnetic anisotropy
Applied Physics Letters, 1993Co-Authors: B M Lairson, M R Visokay, Robert Sinclair, B M ClemensAbstract:We report a technique for producing the ordered PtFe intermetallic compound with perpendicular magnetic anisotropy and a preferred c‐axis orientation perpendicular to the film plane. PtFe alloys possess high magneto‐optic Kerr rotations and magnetizations, suggesting them as likely candidates for magneto‐optic and perpendicular magnetic recording.