Microwave interrogated large core fused silica fiber Michelson interferometer for strain sensing.

Science.gov (United States)

Hua, Liwei; Song, Yang; Huang, Jie; Lan, Xinwei; Li, Yanjun; Xiao, Hai

2015-08-20

A Michelson-type large core optical fiber sensor has been developed, which is designed based on the optical carrier-based microwave interferometry technique, and fabricated by using two pieces of 200-μm diameter fused silica core fiber as two arms of the Michelson interferometer. The interference fringe pattern caused by the optical path difference of the two arms is interrogated in the microwave domain, where the fringe visibility of 40 dB has easily been obtained. The strain sensing at both room temperature and high temperatures has been demonstrated by using such a sensor. Experimental results show that this sensor has a linear response to the applied strain, and also has relatively low temperature-strain cross talk. The dopant-free quality of the fused silica fiber provides high possibility for the sensor to have promising strain sensing performance in a high temperature environment.

A Comparison of Delayed Self-Heterodyne Interference Measurement of Laser Linewidth Using Mach-Zehnder and Michelson Interferometers

Directory of Open Access Journals (Sweden)

Simon Fleming

2011-09-01

Full Text Available Linewidth measurements of a distributed feedback (DFB fibre laser are made using delayed self heterodyne interferometry (DHSI with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are wL (MZI = (1.6 ± 0.2 kHz and wL (MI = (1.4 ± 0.1 kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. This is explained by the unscrambling of polarisation drift using the Faraday rotator mirrors, confirmed by comparing with non-rotating standard gold coated fibre end mirrors.

Modulated Source Interferometry with Combined Amplitude and Frequency Modulation

Science.gov (United States)

Gutierrez, Roman C. (Inventor)

1998-01-01

An improved interferometer is produced by modifying a conventional interferometer to include amplitude and/or frequency modulation of a coherent light source at radio or higher frequencies. The phase of the modulation signal can be detected in an interfering beam from an interferometer and can be used to determine the actual optical phase of the beam. As such, this improvement can be adapted to virtually any two-beam interferometer, including: Michelson, Mach-Zehnder, and Sagnac interferometers. The use of an amplitude modulated coherent tight source results in an interferometer that combines the wide range advantages of coherent interferometry with the precise distance measurement advantages of white light interferometry.

Naked eye picometer resolution in a Michelson interferometer using conjugated twisted beams.

Science.gov (United States)

Emile, Olivier; Emile, Janine

2017-01-15

Michelson interferometry is one of the most widely used techniques for accuracy measurements. Its main characteristic feature is to infer a displacement in one of the arms of the interferometer from a phase measurement. Two different twisted beams, also called vortex beams, with opposite twisted rotations in each arm of the interferometer interfere in a daisy flower-like pattern. The number of petals is twice the topological charge. Their position depends on the relative phase of the beams. Naked eye detection of 44 pm displacements is achieved. The sensitivity of such an interferometer together with possible further improvements, and applications are then discussed.

First mesospheric wind images using the Michelson interferometer for airglow dynamics imaging.

Science.gov (United States)

Langille, J A; Ward, W E; Nakamura, T

2016-12-10

The Michelson interferometer for airglow dynamics imaging (MIADI) is a ground-based instrument that combines an imaging capability with the Doppler Michelson interferometry in order to remotely detect motions in the mesopause region using spectrally isolated airglow emissions: the O(S1) emission at 557.73 nm and the OH (6, 2) P1 (2) at 839.918 nm. A measurement and analysis approach has been developed that allows simultaneous images of the line-of-sight Doppler wind field and irradiance field to be obtained. A working field instrument was installed and tested at a field site outside Fredericton, NB (45.96 N, 66.65 W) during the summer of 2014. Successful measurements over a 6 h period were obtained on 31 July 2014. This paper describes the MIADI measurement and analysis approach and presents the work that has been done to extract images of the line-of-sight Doppler wind field and irradiances from these observations. The imaging capability is validated by identifying the presence of large-scale and small-scale geophysical perturbations in the images.

Semiconductor spintronics

CERN Document Server

Xia, Jianbai; Chang, Kai

2012-01-01

Semiconductor Spintronics, as an emerging research discipline and an important advanced field in physics, has developed quickly and obtained fruitful results in recent decades. This volume is the first monograph summarizing the physical foundation and the experimental results obtained in this field. With the culmination of the authors' extensive working experiences, this book presents the developing history of semiconductor spintronics, its basic concepts and theories, experimental results, and the prospected future development. This unique book intends to provide a systematic and modern foundation for semiconductor spintronics aimed at researchers, professors, post-doctorates, and graduate students, and to help them master the overall knowledge of spintronics.

Metallic spintronic devices

CERN Document Server

Wang, Xiaobin

2014-01-01

Metallic Spintronic Devices provides a balanced view of the present state of the art of metallic spintronic devices, addressing both mainstream and emerging applications from magnetic tunneling junction sensors and spin torque oscillators to spin torque memory and logic. Featuring contributions from well-known and respected industrial and academic experts, this cutting-edge work not only presents the latest research and developments but also: Describes spintronic applications in current and future magnetic recording devicesDiscusses spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device architectures and modelingExplores prospects of STT-MRAM scaling, such as detailed multilevel cell structure analysisInvestigates spintronic device write and read optimization in light of spintronic memristive effectsConsiders spintronic research directions based on yttrium iron garnet thin films, including spin pumping, magnetic proximity, spin hall, and spin Seebeck effectsProposes unique solutions for ...

Spintronics

Indian Academy of Sciences (India)

we will deal in an elementary fashion with the principles of spintronics. Introduction. Spintronics is the branch of science dealing with the ac- tive manipulation of spin degrees of freedom in solid state materials. .... polarized material can be done in many ways. The sim- plest way is to apply a transient magnetic field to a para-.

Active stabilization of a Michelson interferometer at an arbitrary phase with subnanometer resolution.

Science.gov (United States)

Grassani, Davide; Galli, Matteo; Bajoni, Daniele

2014-04-15

We report on the active stabilization of a Michelson interferometer at an arbitrary phase angle with a precision better than 1° at λ=632.8  nm, which corresponds to a precision in the optical path difference between the two arms of less than 1 nm. The stabilization method is ditherless, and the error signal is computed from the spatial shift of the interference pattern of a reference laser, measured in real-time with a CCD array detector. We discuss the usefulness of this method for nanopositioning, optical interferometry, and quantum optical experiments.

DESIGN AND CHARACTERIZATION OF THERMALLY ACTUATED BIMETALLIC MEMBRANES BY MICHELSON INTERFEROMETRY

Directory of Open Access Journals (Sweden)

JULIO ENRIQUE DUARTE

2011-01-01

Full Text Available En el presente trabajo se describen el diseño y la caracterización de membranas bimetálicas de Al-Si, con actuación térmica. El diseño se realizó empleando el método de los Elementos Finitos y se concentró en optimizar la relación de los espesores de las capas de aluminio y silicio. La defl exión de las membranas se determinó aplicando la técnica del Interferómetro de Michelson. En la etapa experimental se utilizaron membranas cuadradas de 5 mm de lado, con un espesor de 10 mm para el silicio y espesores de 4 y 1 mm para el aluminio. La caracterización entregó un desplazamiento máximo de 14 mm para la membrana con 4 mm de Al, lo cual es consistente con los resultados obtenidos numéricamente.

Semiconductor spintronics

International Nuclear Information System (INIS)

Fabian, J.; Abiague, A.M.; Ertler, Ch.; Stano, P.; Zutic, I.

2007-01-01

Spintronics refers commonly to phenomena in which the spin of electrons in a solid state environment plays the determining role. In a more narrow sense spintronics is an emerging research field of electronics: spintronics devices are based on a spin control of electronics, or on an electrical and optical control of spin of magnetism. While metal spintronics has already found its niche in the computer industry - giant magnetoresistance systems are used as hard disk read heads - semiconductor spintronics is vet demonstrate its full potential. This review presents selected themes of semiconductor spintronics, introducing important concepts in spin transport, spin transport, spin injection. Silsbee-Johnson spin-charge coupling, and spin-dependent tunneling, as well as spin relaxation and spin dynamics. The most fundamental spin-dependent interaction in nonmagnetic semiconductors is spin-orbit coupling. Depending on the crystal symmetries of the material, as well as on the structural properties of semiconductor based heterostructures, the spin-orbit coupling takes on different functional forms, giving a nice playground of effective spin-orbit Hamiltonians. The effective Hamiltonians for the most relevant classes of materials and heterostructures are derived here from realistic electronic band structure descriptions. Most semiconductor device systems are still theoretical concepts, waiting for experimental demonstrations. A review of selected proposed, and a few demonstrated devices is presented, with detailed description of two important classes: magnetic resonant tunnel structures and bipolar magnetic diodes and transistors. In view of the importance of ferromagnetic semiconductor material, a brief discussion of diluted magnetic semiconductors is included. In most cases the presentation is of tutorial style, introducing the essential theoretical formalism at an accessible level, with case-study-like illustrations of actual experimental results, as well as with brief

A novel plasmonic interferometry and the potential applications

Directory of Open Access Journals (Sweden)

J. Ali

2018-03-01

Full Text Available In this article, we have proposed the plasmonic interferometry concept and analytical details given. By using the conventional optical interferometry, which can be simply calculated by using the relationship between the electric field and electron mobility, the interference mobility visibility (fringe visibility can be observed. The surface plasmons in the sensing arm of the Michelson interferometer is constructed by the stacked layers of the silicon-graphene-gold, allows to characterize the spatial resolution of light beams in terms of the electron mobility down to 100-nm scales, with measured coherence lengths as low as ∼100 nm for an incident wavelength of 1550 nm. We have demonstrated a compact plasmonic interferometer that can apply to the electron mean free paths measurement, from which the precise determination can be used for the high-resolution mean free path measurement and sensing applications. This system provides the practical simulation device parameters that can be fabricated and tested by the experimental platform.

A novel plasmonic interferometry and the potential applications

Science.gov (United States)

Ali, J.; Pornsuwancharoen, N.; Youplao, P.; Aziz, M. S.; Chiangga, S.; Jaglan, J.; Amiri, I. S.; Yupapin, P.

2018-03-01

In this article, we have proposed the plasmonic interferometry concept and analytical details given. By using the conventional optical interferometry, which can be simply calculated by using the relationship between the electric field and electron mobility, the interference mobility visibility (fringe visibility) can be observed. The surface plasmons in the sensing arm of the Michelson interferometer is constructed by the stacked layers of the silicon-graphene-gold, allows to characterize the spatial resolution of light beams in terms of the electron mobility down to 100-nm scales, with measured coherence lengths as low as ∼100 nm for an incident wavelength of 1550 nm. We have demonstrated a compact plasmonic interferometer that can apply to the electron mean free paths measurement, from which the precise determination can be used for the high-resolution mean free path measurement and sensing applications. This system provides the practical simulation device parameters that can be fabricated and tested by the experimental platform.

Distance measurement using frequency scanning interferometry with mode-hoped laser

Science.gov (United States)

Medhat, M.; Sobee, M.; Hussein, H. M.; Terra, O.

2016-06-01

In this paper, frequency scanning interferometry is implemented to measure distances up to 5 m absolutely. The setup consists of a Michelson interferometer, an external cavity tunable diode laser, and an ultra-low expansion (ULE) Fabry-Pérot (FP) cavity to measure the frequency scanning range. The distance is measured by acquiring simultaneously the interference fringes from, the Michelson and the FP interferometers, while scanning the laser frequency. An online fringe processing technique is developed to calculate the distance from the fringe ratio while removing the parts result from the laser mode-hops without significantly affecting the measurement accuracy. This fringe processing method enables accurate distance measurements up to 5 m with measurements repeatability ±3.9×10-6 L. An accurate translation stage is used to find the FP cavity free-spectral-range and therefore allow accurate measurement. Finally, the setup is applied for the short distance calibration of a laser distance meter (LDM).

Organic spintronics

International Nuclear Information System (INIS)

Naber, W J M; Faez, S; Wiel, W G van der

2007-01-01

We review the emerging field of organic spintronics, where organic materials are applied as a medium to transport and control spin-polarized signals. The contacts for injecting and detecting spins are formed by ferromagnetic metals, oxides, or inorganic semiconductors. First, the basic concepts of spintronics and organic electronics are addressed, and phenomena which are in particular relevant for organic spintronics are highlighted. Experiments using different organic materials, including carbon nanotubes, organic thin films, self-assembled monolayers and single molecules are then reviewed. Observed magnetoresistance points toward successful spin injection and detection, but spurious magnetoresistance effects can easily be confused with spin accumulation. A few studies report long spin relaxation times and lengths, which forms a promising basis for further research. We conclude with discussing outstanding questions and problems. (topical review)

Spintronics: The molecular way

Science.gov (United States)

Cornia, Andrea; Seneor, Pierre

2017-05-01

Molecular spintronics is an interdisciplinary field at the interface between organic spintronics, molecular magnetism, molecular electronics and quantum computing, which is advancing fast and promises large technological payoffs.

The Explanation of Michelson's Experiment

International Nuclear Information System (INIS)

Klinaku, Shukri

2010-01-01

In this paper we will prove that the Lorentz factor doesn't exist on the relative motion. In fact this factor is the result of a wrong calculation of Michelson. His mistake was approved by Lorentz and other physicists, including Einstein. Michelson in order to implement his idea with his interferometer in 1881, made the following mistake: he made the calculation according to the only principle of relativity which was known by physics--the Galileo principle, but he didn't faithfully apply this principle. In this paper, the principle of Galileo will be implemented exactly to Michelson's experiment and the result will show us that physics doesn't need the postulates of the year 1905.

In-fiber integrated Michelson interferometer.

Science.gov (United States)

Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

2006-09-15

A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

Michelson interferometer based spatial phase shift shearography.

Science.gov (United States)

Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

2013-06-10

This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

Development of Phase Detection Schemes Based on Surface Plasmon Resonance Using Interferometry

Directory of Open Access Journals (Sweden)

Muhammad Kashif

2014-08-01

Full Text Available Surface plasmon resonance (SPR is a novel optical sensing technique with a unique ability to monitor molecular binding in real-time for biological and chemical sensor applications. Interferometry is an excellent tool for accurate measurement of SPR changes, the measurement and comparison is made for the sensitivity, dynamic range and resolution of the different analytes using interferometry techniques. SPR interferometry can also employ phase detection in addition to the amplitude of the reflected light wave, and the phase changes more rapidly compared with other approaches, i.e., intensity, angle and wavelength. Therefore, the SPR phase interferometer offers the advantages of spatial phase resolution and high sensitivity. This work discusses the advancements in interferometric SPR methods to measure the phase shifts due to refractive index changes. The main application areas of SPR sensors are demonstrated, i.e., the Fabry-Perot interferometer, Michelson interferometer and Mach-Zehnder interferometer, with different configurations. The three interferometers are discussed in detail, and solutions are suggested to enhance the performance parameters that will aid in future biological and chemical sensors.

Nanostructured graphene for spintronics

DEFF Research Database (Denmark)

Gregersen, Søren Schou; Power, Stephen; Jauho, Antti-Pekka

2017-01-01

Zigzag edges of the honeycomb structure of graphene exhibit magnetic polarization, making them attractive as building blocks for spintronic devices. Here, we show that devices with zigzag-edged triangular antidots perform essential spintronic functionalities, such as spatial spin splitting or spin...

Michelson-Morley in Einstein's elevators

Science.gov (United States)

Pierce, Fred; Pierce, Ayal

2010-02-01

Experiments are proposed in which a Michelson-Morley interferometer is placed in Einstein's thought experiments where elevators are subjected to varied accelerated fields. Unbeknownst to the observers inside the elevators, they are placed in different circumstances: on the surface of the Earth, in free fall, in space distant from any mass, and inside a rotating space station. By use of not one, but two objects, the observer will be challenged to determine the nature and shape of the accelerated field, if any, inside the elevator. It will be demonstrated that the nature of the accelerated field can be determined easily from inside the elevator by the motion of the two objects released by the observer. It will also be shown that, for the elevator on the space station which is generating an ``artificial gravity'' field by rotation, Michelson-Morley would have the same null result as on Earth. However, the Michelson-Morley experiment is adapted so that in addition to the two horizontal arms of the interferometer (parallel to the floor of the elevator) a vertical arm is added perpendicular to the floor facing towards the ceiling. Such a vertical arm added to the Michelson-Morley experiment adds a new dimension to examining each accelerated field, including gravity. )

Michelson interferometer for measuring temperature

Science.gov (United States)

Xie, Dong; Xu, Chunling; Wang, An Min

2017-09-01

We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displaying Kerr nonlinearity. We obtain the analytical equations and numerically calculate the precision with parameters within the reach of current technology, proving that the precision of temperature can be greatly enhanced by using a nonlinear medium. Our results show that one can create an accurate thermometer by measuring the photons in the Michelson interferometer, with no need to directly measure the population of thermalized sample.

Proposal of Michelson-Morley experiment via single photon interferometer: Interpretation of Michelson-Morley experimental results using de Broglie-Bohm picture

OpenAIRE

Sato, Masanori

2004-01-01

The Michelson-Morley experiment is considered via a single photon interferometer and we propose the interpretation of the Michelson-Morley experimental results using de Broglie-Bohm picture. We point out that the Michelson-Morley experiment revealed the interference of photons, however, it did not reveal the photons simultaneous arrival at the beam splitter. According to the de Broglie-Bohm picture, the quantum potential nonlocally determines the interference of photons. The interference of t...

Handbook of spintronics

CERN Document Server

Awschalom, David; Nitta, Junsaku

2016-01-01

This large reference work addresses a broad range of topics covering various aspects of spintronics science and technology, ranging from fundamental physics through materials properties and processing to established and emerging device technology and applications.  It comprises a collection of chapters from a large international team of leading researchers across academia and industry, providing readers with an up-to-date and comprehensive review of this dynamic field of research.   The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including the theory of giant magnetoresistance and an introduction to spin quantum computing.  Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrid materials including Heusler compounds, magnetic semiconductors, molecular spintronic materials, carbon nanotubes and graphene.  A separate section describes the various methods used in the char...

Michelson interferometer for measuring temperature

OpenAIRE

Xie, Dong; Xu, Chunling; wang, Anmin

2016-01-01

We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displa...

Future perspectives for spintronic devices

International Nuclear Information System (INIS)

Hirohata, Atsufumi; Takanashi, Koki

2014-01-01

Spintronics is one of the emerging research fields in nanotechnology and has been growing very rapidly. Studies of spintronics were started after the discovery of giant magnetoresistance in 1988, which utilized spin-polarized electron transport across a non-magnetic metallic layer. Within 10 years, this discovery had been implemented into hard disk drives, the most common storage media, followed by recognition through the award of the Nobel Prize for Physics 19 years later. We have never experienced such fast development in any scientific field. Spintronics research is now moving into second-generation spin dynamics and beyond. In this review, we first examine the historical advances in spintronics together with the background physics, and then describe major device applications. (topical review)

The effect of rotations on Michelson interferometers

Energy Technology Data Exchange (ETDEWEB)

Maraner, Paolo, E-mail: pmaraner@unibz.it

2014-11-15

In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations.

The effect of rotations on Michelson interferometers

International Nuclear Information System (INIS)

Maraner, Paolo

2014-01-01

In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations

Nanomagnetism and spintronics

CERN Document Server

Shinjo, Teruya

2014-01-01

The concise and accessible chapters of Nanomagnetism and Spintronics, Second Edition, cover the most recent research in areas of spin-current generation, spin-calorimetric effect, voltage effects on magnetic properties, spin-injection phenomena, giant magnetoresistance (GMR), and tunnel magnetoresistance (TMR). Spintronics is a cutting-edge area in the field of magnetism that studies the interplay of magnetism and transport phenomena, demonstrating how electrons not only have charge but also spin. This second edition provides the background to understand this novel physical phenomeno

Michelson Interferometer

Science.gov (United States)

Rogers, Ryan

2007-01-01

The Michelson Interferometer is a device used in many applications, but here it was used to measure small differences in distance, in the milli-inch range, specifically for defects in the Orbiter windows. In this paper, the method of using the Michelson Interferometer for measuring small distances is explained as well as the mathematics of the system. The coherence length of several light sources was calculated in order to see just how small a defect could be measured. Since white light is a very broadband source, its coherence length is very short and thus can be used to measure small defects in glass. After finding the front and back reflections from a very thin glass slide with ease and calculating the thickness of it very accurately, it was concluded that this system could find and measure small defects on the Orbiter windows. This report also discusses a failed attempt for another use of this technology as well as describes an area of promise for further analysis. The latter of these areas has applications for finding possible defects in Orbiter windows without moving parts.

Antiferromagnetic spintronics

KAUST Repository

Baltz, V.

2018-02-15

Antiferromagnetic materials could represent the future of spintronic applications thanks to the numerous interesting features they combine: they are robust against perturbation due to magnetic fields, produce no stray fields, display ultrafast dynamics, and are capable of generating large magnetotransport effects. Intense research efforts over the past decade have been invested in unraveling spin transport properties in antiferromagnetic materials. Whether spin transport can be used to drive the antiferromagnetic order and how subsequent variations can be detected are some of the thrilling challenges currently being addressed. Antiferromagnetic spintronics started out with studies on spin transfer and has undergone a definite revival in the last few years with the publication of pioneering articles on the use of spin-orbit interactions in antiferromagnets. This paradigm shift offers possibilities for radically new concepts for spin manipulation in electronics. Central to these endeavors are the need for predictive models, relevant disruptive materials, and new experimental designs. This paper reviews the most prominent spintronic effects described based on theoretical and experimental analysis of antiferromagnetic materials. It also details some of the remaining bottlenecks and suggests possible avenues for future research. This review covers both spin-transfer-related effects, such as spin-transfer torque, spin penetration length, domain-wall motion, and

Antiferromagnetic spintronics

KAUST Repository

Baltz, V.; Manchon, Aurelien; Tsoi, M.; Moriyama, T.; Ono, T.; Tserkovnyak, Y.

2018-01-01

Antiferromagnetic materials could represent the future of spintronic applications thanks to the numerous interesting features they combine: they are robust against perturbation due to magnetic fields, produce no stray fields, display ultrafast dynamics, and are capable of generating large magnetotransport effects. Intense research efforts over the past decade have been invested in unraveling spin transport properties in antiferromagnetic materials. Whether spin transport can be used to drive the antiferromagnetic order and how subsequent variations can be detected are some of the thrilling challenges currently being addressed. Antiferromagnetic spintronics started out with studies on spin transfer and has undergone a definite revival in the last few years with the publication of pioneering articles on the use of spin-orbit interactions in antiferromagnets. This paradigm shift offers possibilities for radically new concepts for spin manipulation in electronics. Central to these endeavors are the need for predictive models, relevant disruptive materials, and new experimental designs. This paper reviews the most prominent spintronic effects described based on theoretical and experimental analysis of antiferromagnetic materials. It also details some of the remaining bottlenecks and suggests possible avenues for future research. This review covers both spin-transfer-related effects, such as spin-transfer torque, spin penetration length, domain-wall motion, and

A new polarized neutron interferometry facility at the NCNR

Energy Technology Data Exchange (ETDEWEB)

Shahi, C.B. [Physics and Engineering Physics Department, Tulane University, New Orleans, LA 70188 (United States); Arif, M. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Cory, D.G. [Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, ON, Canada N2L 2Y5 (Canada); Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Canadian Institute for Advanced Research, Toronto, ON, Canada M5G 1Z8 (Canada); Mineeva, T. [Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Canadian Institute for Advanced Research, Toronto, ON, Canada M5G 1Z8 (Canada); Nsofini, J.; Sarenac, D. [Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Williams, C.J. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Huber, M.G., E-mail: michael.huber@nist.gov [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Pushin, D.A., E-mail: dmitry.pushin@uwaterloo.ca [Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada)

2016-03-21

A new monochromatic beamline and facility has been installed at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR) devoted to neutron interferometry in the research areas of spin control, spin manipulation, quantum mechanics, quantum information science, spintronics, and material science. This facility is possible in part because of advances in decoherence free subspace interferometer designs that have demonstrated consistent contrast in the presence of vibrational noise; a major environmental constraint that has prevented neutron interferometry from being applied at other neutron facilities. Neutron interferometry measures the phase difference between a neutron wave function propagating along two spatially separated paths. It is a practical example of self interference and due to its modest path separation of a few centimeters allows the insertion of samples and macroscopic neutron spin rotators. Phase shifts can be caused by gravitational, magnetic and nuclear interactions as well as purely quantum mechanical effects making interferometer a robust tool in neutron research. This new facility is located in the guide hall of the NCNR upstream of the existing Neutron Interferometry and Optics Facility (NIOF) and has several advantages over the NIOF including higher incident flux, better neutron polarization, and increased accessibility. The long term goal for the new facility is to be a user supported beamline and makes neutron interferometer more generally available to the scientific community. This paper addresses both the capabilities and characteristics of the new facility.

Measurement of Three-Dimensional Deformations by Phase-Shifting Digital Holographic Interferometry

Directory of Open Access Journals (Sweden)

Percival Almoro

2003-06-01

Full Text Available Out-of-plane deformations of a cantilever were measured using phase-shifting digital holographicinterferometry (PSDHI and the Fourier transform method (FTM. The cantilever was recorded in twodifferent states, and holograms were stored electronically with a charge-coupled device (CCD camera.When the holograms are superimposed and reconstructed jointly, a holographic interferogram results.The three-dimensional (3D surface deformations were successfully visualized by applying FTM toholographic interferogram analysis. The minimum surface displacement measured was 0.317 µm. Theprocessing time for the digital reconstruction and visualization of 3D deformation took about 1 minute.The technique was calibrated using Michelson interferometry setup.

Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)

Science.gov (United States)

Roberts, B.

1986-01-01

The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

Spintronics Based on Topological Insulators

Science.gov (United States)

Fan, Yabin; Wang, Kang L.

2016-10-01

Spintronics using topological insulators (TIs) as strong spin-orbit coupling (SOC) materials have emerged and shown rapid progress in the past few years. Different from traditional heavy metals, TIs exhibit very strong SOC and nontrivial topological surface states that originate in the bulk band topology order, which can provide very efficient means to manipulate adjacent magnetic materials when passing a charge current through them. In this paper, we review the recent progress in the TI-based magnetic spintronics research field. In particular, we focus on the spin-orbit torque (SOT)-induced magnetization switching in the magnetic TI structures, spin-torque ferromagnetic resonance (ST-FMR) measurements in the TI/ferromagnet structures, spin pumping and spin injection effects in the TI/magnet structures, as well as the electrical detection of the surface spin-polarized current in TIs. Finally, we discuss the challenges and opportunities in the TI-based spintronics field and its potential applications in ultralow power dissipation spintronic memory and logic devices.

Boron nitride nanotubes for spintronics.

Science.gov (United States)

Dhungana, Kamal B; Pati, Ranjit

2014-09-22

With the end of Moore's law in sight, researchers are in search of an alternative approach to manipulate information. Spintronics or spin-based electronics, which uses the spin state of electrons to store, process and communicate information, offers exciting opportunities to sustain the current growth in the information industry. For example, the discovery of the giant magneto resistance (GMR) effect, which provides the foundation behind modern high density data storage devices, is an important success story of spintronics; GMR-based sensors have wide applications, ranging from automotive industry to biology. In recent years, with the tremendous progress in nanotechnology, spintronics has crossed the boundary of conventional, all metallic, solid state multi-layered structures to reach a new frontier, where nanostructures provide a pathway for the spin-carriers. Different materials such as organic and inorganic nanostructures are explored for possible applications in spintronics. In this short review, we focus on the boron nitride nanotube (BNNT), which has recently been explored for possible applications in spintronics. Unlike many organic materials, BNNTs offer higher thermal stability and higher resistance to oxidation. It has been reported that the metal-free fluorinated BNNT exhibits long range ferromagnetic spin ordering, which is stable at a temperature much higher than room temperature. Due to their large band gap, BNNTs are also explored as a tunnel magneto resistance device. In addition, the F-BNNT has recently been predicted as an ideal spin-filter. The purpose of this review is to highlight these recent progresses so that a concerted effort by both experimentalists and theorists can be carried out in the future to realize the true potential of BNNT-based spintronics.

Boron Nitride Nanotubes for Spintronics

Directory of Open Access Journals (Sweden)

Kamal B. Dhungana

2014-09-01

Full Text Available With the end of Moore’s law in sight, researchers are in search of an alternative approach to manipulate information. Spintronics or spin-based electronics, which uses the spin state of electrons to store, process and communicate information, offers exciting opportunities to sustain the current growth in the information industry. For example, the discovery of the giant magneto resistance (GMR effect, which provides the foundation behind modern high density data storage devices, is an important success story of spintronics; GMR-based sensors have wide applications, ranging from automotive industry to biology. In recent years, with the tremendous progress in nanotechnology, spintronics has crossed the boundary of conventional, all metallic, solid state multi-layered structures to reach a new frontier, where nanostructures provide a pathway for the spin-carriers. Different materials such as organic and inorganic nanostructures are explored for possible applications in spintronics. In this short review, we focus on the boron nitride nanotube (BNNT, which has recently been explored for possible applications in spintronics. Unlike many organic materials, BNNTs offer higher thermal stability and higher resistance to oxidation. It has been reported that the metal-free fluorinated BNNT exhibits long range ferromagnetic spin ordering, which is stable at a temperature much higher than room temperature. Due to their large band gap, BNNTs are also explored as a tunnel magneto resistance device. In addition, the F-BNNT has recently been predicted as an ideal spin-filter. The purpose of this review is to highlight these recent progresses so that a concerted effort by both experimentalists and theorists can be carried out in the future to realize the true potential of BNNT-based spintronics.

Focused issue on antiferromagnetic spintronics: An overview (Part of a collection of reviews on antiferromagnetic spintronics)

KAUST Repository

Jungwirth, T.

2017-05-30

This focused issue attempts to provide a comprehensive introduction into the field of antiferromagnetic spintronics. Apart from the brief overview below, it features five review articles. The intention is to cover in a coherent and complementary way key physical aspects of the antiferromagnetic spintronics research. These range from microelectronic memory devices and optical manipulation and detection of antiferromagnetic spins, to the fundamentals of antiferromagnetic dynamics in uniform or spin-textured systems, and to the interplay of antiferromagnetic spintronics with topological phenomena. The antiferromagnetic ordering can take a number of forms including fully compensated collinear, non-collinear, and non-coplanar magnetic lattices, compensated and uncompensated ferrimagnets, or metamagnetic materials hosting an antiferromagnetic to ferromagnetic phase transition. Apart from the variety of distinct magnetic crystal structures, the focused issue also encompasses spintronic phenomena and devices studied in antiferromagnet/ferromagnet heterostructures and in synthetic antiferromagnets.

Focused issue on antiferromagnetic spintronics: An overview (Part of a collection of reviews on antiferromagnetic spintronics)

KAUST Repository

Jungwirth, T.; Sinova, J.; Manchon, Aurelien; Marti, X.; Wunderlich, J.; Felser, C.

2017-01-01

This focused issue attempts to provide a comprehensive introduction into the field of antiferromagnetic spintronics. Apart from the brief overview below, it features five review articles. The intention is to cover in a coherent and complementary way key physical aspects of the antiferromagnetic spintronics research. These range from microelectronic memory devices and optical manipulation and detection of antiferromagnetic spins, to the fundamentals of antiferromagnetic dynamics in uniform or spin-textured systems, and to the interplay of antiferromagnetic spintronics with topological phenomena. The antiferromagnetic ordering can take a number of forms including fully compensated collinear, non-collinear, and non-coplanar magnetic lattices, compensated and uncompensated ferrimagnets, or metamagnetic materials hosting an antiferromagnetic to ferromagnetic phase transition. Apart from the variety of distinct magnetic crystal structures, the focused issue also encompasses spintronic phenomena and devices studied in antiferromagnet/ferromagnet heterostructures and in synthetic antiferromagnets.

Michelson and His Interferometer

Science.gov (United States)

Shankland, Robert S.

1974-01-01

Presents a brief historical account of Michelson's invention of his interferometer with some subsequent ingenious applications of its capabilities for precise measurement discussed in details, including the experiment on detrmination of the diameters for heavenly bodies. (CC)

Perspectives of antiferromagnetic spintronics

Science.gov (United States)

Jungfleisch, Matthias B.; Zhang, Wei; Hoffmann, Axel

2018-04-01

Antiferromagnets are promising for future spintronic applications owing to their advantageous properties: They are magnetically ordered, but neighboring magnetic moments point in opposite directions, which results in zero net magnetization. This means antiferromagnets produce no stray fields and are insensitive to external magnetic field perturbations. Furthermore, they show intrinsic high frequency dynamics, exhibit considerable spin-orbit and magneto-transport effects. Over the past decade, it has been realized that antiferromagnets have more to offer than just being utilized as passive components in exchange bias applications. This development resulted in a paradigm shift, which opens the pathway to novel concepts using antiferromagnets for spin-based technologies and applications. This article gives a broad perspective on antiferromagnetic spintronics. In particular, the manipulation and detection of antiferromagnetic states by spintronics effects, as well as spin transport and dynamics in antiferromagnetic materials will be discussed. We will also outline current challenges and future research directions in this emerging field.

Perspectives of antiferromagnetic spintronics

Energy Technology Data Exchange (ETDEWEB)

Jungfleisch, Matthias B.; Zhang, Wei; Hoffmann, Axel

2018-04-01

Antiferromagnets are promising for future spintronics applications owing to their interesting properties: They are magnetically ordered, but neighboring magnetic moments point in opposite directions which results in zero net magneti- zation. This means antiferromagnets produce no stray fields and are insensitive to external magnetic field perturbations. Furthermore, they show intrinsic high frequency dynamics, exhibit considerable spin-orbit and magneto-transport effects. Over the past decade, it has been realized that antiferromagnets have more to offer than just being utilized as passive components in exchange bias applications. This development resulted in a paradigm shift, which opens the pathway to novel concepts using antiferromagnets for spin-based technologies and applications. This article gives a broad per- spective on antiferromagnetic spintronics. In particular, the manipulation and detection of anitferromagnetic states by spintronics effects, as well as spin transport and dynamics in antiferromagnetic materials will be discussed. We will also outline current challenges and future research directions in this emerging field.

On the importance of the Michelson-Morley experiment

International Nuclear Information System (INIS)

Strel'tsov, V.N.

1992-01-01

The opinion of an important role of the Michelson-Morley experiment in the establishment of the pronciple oof the light velocity constancy is expressed. It is stressed that the used of radar length for the treatment of the Michelson-Morley experiment leads to the elongation formulas for the longitudinal arm of an interferometer. 24 refs

Antiferromagnetic spintronics

Science.gov (United States)

Baltz, V.; Manchon, A.; Tsoi, M.; Moriyama, T.; Ono, T.; Tserkovnyak, Y.

2018-01-01

Antiferromagnetic materials could represent the future of spintronic applications thanks to the numerous interesting features they combine: they are robust against perturbation due to magnetic fields, produce no stray fields, display ultrafast dynamics, and are capable of generating large magnetotransport effects. Intense research efforts over the past decade have been invested in unraveling spin transport properties in antiferromagnetic materials. Whether spin transport can be used to drive the antiferromagnetic order and how subsequent variations can be detected are some of the thrilling challenges currently being addressed. Antiferromagnetic spintronics started out with studies on spin transfer and has undergone a definite revival in the last few years with the publication of pioneering articles on the use of spin-orbit interactions in antiferromagnets. This paradigm shift offers possibilities for radically new concepts for spin manipulation in electronics. Central to these endeavors are the need for predictive models, relevant disruptive materials, and new experimental designs. This paper reviews the most prominent spintronic effects described based on theoretical and experimental analysis of antiferromagnetic materials. It also details some of the remaining bottlenecks and suggests possible avenues for future research. This review covers both spin-transfer-related effects, such as spin-transfer torque, spin penetration length, domain-wall motion, and "magnetization" dynamics, and spin-orbit related phenomena, such as (tunnel) anisotropic magnetoresistance, spin Hall, and inverse spin galvanic effects. Effects related to spin caloritronics, such as the spin Seebeck effect, are linked to the transport of magnons in antiferromagnets. The propagation of spin waves and spin superfluids in antiferromagnets is also covered.

Albert Abraham Michelson

Indian Academy of Sciences (India)

Some experiments change the face of a subject, and some experiments do that many times over. Albert Michelson built his interferometer in order to determine the effect of Earth's rotation on the speed of light. The null result supported the crucial assumption in Einstein's special theory of relativity and was the final nail in the ...

Studies of elements used in hertzian interferometry (millimetric waves). Measurement of the permittivity of a liquid dielectric; Etudes d'elements utilises en interferometrie hertzienne (ondes millimetriques). Mesure de la permittivite de dielectrique liquide

Energy Technology Data Exchange (ETDEWEB)

Dagai, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-12-01

Study of some elements used in EHF interferometry (bond of millimeter waves). This study is about design of the following elements: horns, horns associated with lens, power separators: -) Study of assemblies allowing measurements of complex dielectric constants of liquids. These devices are used in free propagation about wave lengths {<=} 2 mm; -) Studied devices: Interferometer for 2 separated waves and Michelson's type interferometer; -) 4 liquids have been used: {epsilon}'{sub r} Octane from -50 to 70 C (-58 to 158 F), {epsilon}'{sub r} and {epsilon}'' [Monochlorobenzene at 22,8 C (73 F), Mixture of octane with 10,8 per cent citral at 22 C (72 F) and Benzene at 21 C (70 F)]. -) Precision obtained about measurements: {delta}{epsilon}'/{epsilon}' de 1 a 2%, {delta}{epsilon}''/{epsilon}'' de 4 a 6%.(author) [French] Etudes d'elements utilises en interferometrie hertzienne fonctionnant en ondes millimetriques. Cette etude porte sur la realisation des elements suivants: cornets, cornets associes aux lentilles, separateurs de puissance. Etudes des montages permettant les mesures de la constante dielectrique complexe des corps liquides. Ces montages fonctionnent en propagation libre, sur des longueurs d'onde inferieures ou egales a 2 millimetres. Les montages etudies sont: interferometre a deux ondes separees et interferometre du type Michelson. De plus 4 liquides ont ete etudies: {epsilon}'{sub r} octane de -50 a 70 C, {epsilon}'{sub r} et {epsilon}'' [monochlorobenzene a 22,8 C et melange octane avec 10,8 pour cent citral a 22 C, Benzene a 21 C]. Les precisions obtenues sur les mesures sont: {delta}{epsilon}'/{epsilon}' de 1 a 2 pour cent, {delta}{epsilon}''/{epsilon}'' de 4 a 6 pour cent.

Spintronics-based computing

CERN Document Server

Prenat, Guillaume

2015-01-01

This book provides a comprehensive introduction to spintronics-based computing for the next generation of ultra-low power/highly reliable logic, which is widely considered a promising candidate to replace conventional, pure CMOS-based logic. It will cover aspects from device to system-level, including magnetic memory cells, device modeling, hybrid circuit structure, design methodology, CAD tools, and technological integration methods. This book is accessible to a variety of readers and little or no background in magnetism and spin electronics are required to understand its content.  The multidisciplinary team of expert authors from circuits, devices, computer architecture, CAD and system design reveal to readers the potential of spintronics nanodevices to reduce power consumption, improve reliability and enable new functionality.  .

Computerized evaluation optical measuring thin films by the help of Michelson`s interferometer

Czech Academy of Sciences Publication Activity Database

Bartoněk, L.; Keprt, Jiří

2002-01-01

Roč. 9, č. 2 (2002), s. 27-34 ISSN 1335-0803 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : Michelson `s interferometer * computerized evaluation Subject RIV: BH - Optics, Masers, Lasers

Spin-chemistry concepts for spintronics scientists

Directory of Open Access Journals (Sweden)

Konstantin L. Ivanov

2017-07-01

Full Text Available Spin chemistry and spintronics developed independently and with different terminology. Until now, the interaction between the two fields has been very limited. In this review, we compile the two “languages” in an effort to enhance communication. We expect that knowledge of spin chemistry will accelerate progress in spintronics.

Spintronics with multiferroics

Science.gov (United States)

Béa, H.; Gajek, M.; Bibes, M.; Barthélémy, A.

2008-10-01

In this paper, we review the recent research on the functionalization of multiferroics for spintronics applications. We focus more particularly on antiferromagnetic and ferroelectric BiFeO3 and its integration in several types of architectures. For instance, when used as a tunnel barrier, BiFeO3 allows the observation of a large tunnel magnetoresistance with Co and (La,Sr)MnO3 ferromagnetic electrodes. Also, its antiferromagnetic and magnetoelectric properties have been exploited to induce an exchange coupling with a ferromagnet. The mechanisms of such an exchange coupling open ways to electrically control magnetization and possibly the logic state of spintronics devices. We also discuss recent results concerning the use of ferromagnetic and ferroelectric (La,Bi)MnO3 as an active tunnel barrier in magnetic tunnel junctions with Au and (La,Sr)MnO3 electrodes. A four-resistance-state device has been obtained, with two states arising from a spin filtering effect due to the ferromagnetic character of the barrier and two resulting from the ferroelectric behavior of the (La,Bi)MnO3 ultrathin film. These results show that the additional degree of freedom provided by the ferroelectric polarization brings novel functionalities to spintronics, either as a extra order parameter for multiple-state memory elements, or as a handle for gate-controlled magnetic memories.

Spintronics with multiferroics

International Nuclear Information System (INIS)

Bea, H; Gajek, M; Bibes, M; Barthelemy, A

2008-01-01

In this paper, we review the recent research on the functionalization of multiferroics for spintronics applications. We focus more particularly on antiferromagnetic and ferroelectric BiFeO 3 and its integration in several types of architectures. For instance, when used as a tunnel barrier, BiFeO 3 allows the observation of a large tunnel magnetoresistance with Co and (La,Sr)MnO 3 ferromagnetic electrodes. Also, its antiferromagnetic and magnetoelectric properties have been exploited to induce an exchange coupling with a ferromagnet. The mechanisms of such an exchange coupling open ways to electrically control magnetization and possibly the logic state of spintronics devices. We also discuss recent results concerning the use of ferromagnetic and ferroelectric (La,Bi)MnO 3 as an active tunnel barrier in magnetic tunnel junctions with Au and (La,Sr)MnO 3 electrodes. A four-resistance-state device has been obtained, with two states arising from a spin filtering effect due to the ferromagnetic character of the barrier and two resulting from the ferroelectric behavior of the (La,Bi)MnO 3 ultrathin film. These results show that the additional degree of freedom provided by the ferroelectric polarization brings novel functionalities to spintronics, either as a extra order parameter for multiple-state memory elements, or as a handle for gate-controlled magnetic memories.

Spintronics with multiferroics

Energy Technology Data Exchange (ETDEWEB)

Bea, H; Gajek, M; Bibes, M; Barthelemy, A [Unite Mixte de Physique CNRS/Thales, Route departementale 128, F-91767 Palaiseau (France); Universite Paris-Sud, 91405 Orsay (France)], E-mail: agnes.barthelemy@thalesgroup.com

2008-10-29

In this paper, we review the recent research on the functionalization of multiferroics for spintronics applications. We focus more particularly on antiferromagnetic and ferroelectric BiFeO{sub 3} and its integration in several types of architectures. For instance, when used as a tunnel barrier, BiFeO{sub 3} allows the observation of a large tunnel magnetoresistance with Co and (La,Sr)MnO{sub 3} ferromagnetic electrodes. Also, its antiferromagnetic and magnetoelectric properties have been exploited to induce an exchange coupling with a ferromagnet. The mechanisms of such an exchange coupling open ways to electrically control magnetization and possibly the logic state of spintronics devices. We also discuss recent results concerning the use of ferromagnetic and ferroelectric (La,Bi)MnO{sub 3} as an active tunnel barrier in magnetic tunnel junctions with Au and (La,Sr)MnO{sub 3} electrodes. A four-resistance-state device has been obtained, with two states arising from a spin filtering effect due to the ferromagnetic character of the barrier and two resulting from the ferroelectric behavior of the (La,Bi)MnO{sub 3} ultrathin film. These results show that the additional degree of freedom provided by the ferroelectric polarization brings novel functionalities to spintronics, either as a extra order parameter for multiple-state memory elements, or as a handle for gate-controlled magnetic memories.

Antiferromagnetic spintronics

Czech Academy of Sciences Publication Activity Database

Jungwirth, Tomáš; Martí, Xavier; Wadley, P.; Wunderlich, Joerg

2016-01-01

Roč. 11, č. 3 (2016), 231-241 ISSN 1748-3387 R&D Projects: GA MŠk(CZ) LM2011026; GA ČR GB14-37427G EU Projects: European Commission(XE) 268066 - 0MSPIN Institutional support: RVO:68378271 Keywords : antiferromagnets * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 38.986, year: 2016

Dynamic Circuit Model for Spintronic Devices

KAUST Repository

Alawein, Meshal

2017-01-09

In this work we propose a finite-difference scheme based circuit model of a general spintronic device and benchmark it with other models proposed for spintronic switching devices. Our model is based on the four-component spin circuit theory and utilizes the widely used coupled stochastic magnetization dynamics/spin transport framework. In addition to the steady-state analysis, this work offers a transient analysis of carrier transport. By discretizing the temporal and spatial derivatives to generate a linear system of equations, we derive new and simple finite-difference conductance matrices that can, to the first order, capture both static and dynamic behaviors of a spintronic device. We also discuss an extension of the spin modified nodal analysis (SMNA) for time-dependent situations based on the proposed scheme.

Dynamic Circuit Model for Spintronic Devices

KAUST Repository

Alawein, Meshal; Fariborzi, Hossein

2017-01-01

In this work we propose a finite-difference scheme based circuit model of a general spintronic device and benchmark it with other models proposed for spintronic switching devices. Our model is based on the four-component spin circuit theory and utilizes the widely used coupled stochastic magnetization dynamics/spin transport framework. In addition to the steady-state analysis, this work offers a transient analysis of carrier transport. By discretizing the temporal and spatial derivatives to generate a linear system of equations, we derive new and simple finite-difference conductance matrices that can, to the first order, capture both static and dynamic behaviors of a spintronic device. We also discuss an extension of the spin modified nodal analysis (SMNA) for time-dependent situations based on the proposed scheme.

Maurice Car̊me'i lihtsad laulud lastele / Helle Michelson

Index Scriptorium Estoniae

Michelson, Helle, 1929-

2003-01-01

Car̊me, Maurice. Muinasjutud Caprine'ile / tõlkinud Helle Michelson. [Tallinn] : Tiritamm, 2002 ; Car̊me, Maurice. Naeruhull kirsipuu : [luuletused] / prantsuse keelest tõlkinud Helvi Jürisson. [Tallinn] : Tiritamm, 2002 ; Car̊me, Maurice. Margareetapäev : [jutustused] / tõlkinud Helle Michelson. [Tallinn] : Varrak, 2000

Lembit Michelsoni CV / Lembit Michelson

Index Scriptorium Estoniae

Michelson, Lembit, 1960-

2011-01-01

Fotograaf Lembit Michelson meenutab lapsepõlve- ja kooliaastaid, sõjaväeteenistust, tööd fotograafina nõukogude ajal. Viimased 15 aastat töötab oma foto- ja disainistuudios Akriibia. Erinevatest fotoseeriatest. Artiklile lisatud 7 Lembit Michelsoni kirjutatud luuletust

Spintronics from materials to devices

CERN Document Server

Felser, Claudia

2013-01-01

Spintronics is an emerging technology exploiting the spin degree of freedom and has proved to be very promising for new types of fast electronic devices. Amongst the anticipated advantages of spintronics technologies, researchers have identified the non-volatile storage of data with high density and low energy consumption as particularly relevant. This monograph examines the concept of half-metallic compounds perspectives to obtain novel solutions and discusses several oxides such as perovskites, double perovskites and CrO2 as well as Heusler compounds. Such materials can be designed and made

Integrated fiber Michelson interferometer based on poled hollow twin-core fiber.

Science.gov (United States)

Liu, Zhihai; Bo, Fusen; Wang, Lei; Tian, Fengjun; Yuan, Libo

2011-07-01

We propose an integrated fiber Michelson interferometer based on a poled hollow twin-core fiber. The Michelson interferometer can be used as an electro-optic modulator by thermal poling one core of the twin-core fiber and introducing second-order nonlinearity in the fiber. The proposed fiber Michelson interferometer is experimentally demonstrated under driving voltages at the frequency range of 149 to 1000 Hz. The half-wave voltage of the poled fiber is 135 V, and the effective second-order nonlinear coefficient χ² is 1.23 pm/V.

The Michelson Era in American Science, 1870--1930

International Nuclear Information System (INIS)

Goldberg, S.; Stuewer, R.H.

1988-01-01

The articles in this volume relate, in one way or another, to a single experiment: the Michelson-Morley ether-drift experiment of 1887. About one-half of the articles in the collection are based on papers delivered at a two-day symposium ''The Michelson Era in American Science: 1870--1930,'' held a Case Western Reserve University in Cleveland, Ohio, 28--29 October 1987, commemorating the centennial of the experiment. The Michelson-Morley experiment was designed to detect the motion of the earth through the luminiferous ether. At the time, physicists did not question the existence of the ether. The experiment, like many physical probes of nature, was simple in conception, yet uncompromisingly demanding of the art of contemporary craftsmanship. The state of the mechanical arts and its relationship to the pursuit of physical science in late nineteenth- century America is well documented in Section I, which also addresses the more general question of the link between state-of-the-art shop practice and engineering theory

Spintronics and thermoelectrics in exfoliated and epitaxial graphene

NARCIS (Netherlands)

van den Berg, Jan Jasper

2016-01-01

This thesis is about two subjects: graphene spintronics and graphene thermoelectrics. Spintronics is about the creation and manipulation of spin currents. These are electrical currents in which we can control the spin orientation (up or down) of the conduction electrons. The second subject,

Michelson interferometer based interleaver design using classic IIR filter decomposition.

Science.gov (United States)

Cheng, Chi-Hao; Tang, Shasha

2013-12-16

An elegant method to design a Michelson interferometer based interleaver using a classic infinite impulse response (IIR) filter such as Butterworth, Chebyshev, and elliptic filters as a starting point are presented. The proposed design method allows engineers to design a Michelson interferometer based interleaver from specifications seamlessly. Simulation results are presented to demonstrate the validity of the proposed design method.

Dual-recycled cavity-enhanced Michelson interferometer for gravitational-wave detection.

Science.gov (United States)

Müller, Guido; Delker, Tom; Tanner, David B; Reitze, David

2003-03-01

The baseline design for an Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO) is a dual-recycled Michelson interferometer with cavities in each of the Michelson interferometer arms. We describe one possible length-sensing and control scheme for such a dual-recycled, cavity-enhanced Michelson interferometer. We discuss the principles of this scheme and derive the first-order sensing signals. We also present a successful experimental verification of our length-sensing system using a prototype tabletop interferometer. Our results demonstrate the robustness of the scheme against deviations from the idealized design. We also identify potential weaknesses and discuss possible improvements. These results as well as other benchtop experiments that we present form the basis for a sensing and control scheme for Advanced LIGO.

Laser Micromachining and Information Discovery Using a Dual Beam Interferometry

Energy Technology Data Exchange (ETDEWEB)

Theppakuttaikomaraswamy, Senthil P. [Iowa State Univ., Ames, IA (United States)

2001-01-01

Lasers have proven to be among the most promising tools for micromachining because they can process features down to the size of the laser wavelength (smaller than 1 micrometer) and they provide a non-contact technology for machining. The demand for incorporating in-situ diagnostics technology into the micromachining environment is driven by the increasing need for producing micro-parts of high quality and accuracy. Laser interferometry can be used as an on-line monitoring tool and it is the aim of this work to enhance the understanding and application of Michelson interferometry principle for the in-situ diagnostics of the machining depth on the sub-micron and micron scales. micromachining is done on two different materials and a comprehensive investigation is done to control the width and depth of the machined feature. To control the width of the feature, laser micromachining is done on copper and a detailed analysis is performed. The objective of this experiment is to make a precision mask for sputtering with an array of holes on it using an Nd:YAG laser of 532 nm wavelength. The diameter of the hole is 50 μm and the spacing between holes (the distance between the centers) is 100 μm. Michelson interferometer is integrated with a laser machining system to control the depth of machining. An excimer laser of 308 nm wavelength is used for micromachining. A He-Ne laser of 632.8 nm wavelength is used as the light source for the interferometer. Interference patterns are created due to the change in the path length between the two interferometer arms. The machined depth information is obtained from the interference patterns on an oscilloscope detected by a photodiode. To compare the predicted depth by the interferometer with the true machining depth, a surface profilometer is used to measure the actual machining depth on the silicon. It is observed that the depths of machining obtained by the surface profile measurement are in accordance with the interferometer

Experimental demonstration of deep frequency modulation interferometry.

Science.gov (United States)

Isleif, Katharina-Sophie; Gerberding, Oliver; Schwarze, Thomas S; Mehmet, Moritz; Heinzel, Gerhard; Cervantes, Felipe Guzmán

2016-01-25

Experiments for space and ground-based gravitational wave detectors often require a large dynamic range interferometric position readout of test masses with 1 pm/√Hz precision over long time scales. Heterodyne interferometer schemes that achieve such precisions are available, but they require complex optical set-ups, limiting their scalability for multiple channels. This article presents the first experimental results on deep frequency modulation interferometry, a new technique that combines sinusoidal laser frequency modulation in unequal arm length interferometers with a non-linear fit algorithm. We have tested the technique in a Michelson and a Mach-Zehnder Interferometer topology, respectively, demonstrated continuous phase tracking of a moving mirror and achieved a performance equivalent to a displacement sensitivity of 250 pm/Hz at 1 mHz between the phase measurements of two photodetectors monitoring the same optical signal. By performing time series fitting of the extracted interference signals, we measured that the linearity of the laser frequency modulation is on the order of 2% for the laser source used.

Noise Studies of Externally Dispersed Interferometry for Doppler Velocimetry

International Nuclear Information System (INIS)

Erskine, D J; Edelstein, J; Lloyd, J; Muirhead, P

2006-01-01

Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. Both regular and high-frequency spectral components can be recovered from the data--the moire component carries additional information that increases the signal to noise for velocimetry and spectroscopy. Here we present simulations and theoretical studies of the photon limited Doppler velocity noise in an EDI. We used a model spectrum of a 1600K temperature star. For several rotational blurring velocities 0, 7.5, 15 and 25 km/s we calculated the dimensionless Doppler quality index (Q) versus wavenumber v. This is the normalized RMS of the derivative of the spectrum and is proportional to the photon-limited Doppler signal to noise ratio

Optical displacement measurement with GaAs/AlGaAs-based monolithically integrated Michelson interferometers

OpenAIRE

Hofstetter, Daniel; Zappe, H. P.; Dändliker, René

2008-01-01

Two monolithically integrated optical displacement sensors fabricated in the GaAs/AlGaAs material system are reported. These single-chip microsystems are configured as Michelson interferometers and comprise a distributed Bragg reflector (DBR) laser, photodetectors, phase shifters, and waveguide couplers. While the use of a single Michelson interferometer allows measurement of displacement magnitude only, a double Michelson interferometer with two interferometer signals in phase quadrature als...

Reduction of chromatic aberration influences in vertical scanning white-light interferometry

International Nuclear Information System (INIS)

Lehmann, Peter; Kühnhold, Peter; Xie, Weichang

2014-01-01

Vertical scanning white-light interferometry (SWLI) is a well-established method that is widely used in high precision surface topography measurement. However, SWLI results show characteristic slope-dependent errors due to dispersion effects and lateral chromatic aberrations of the optical imaging system. In this paper, we present methods to characterize these systematic errors related to dispersion and lateral colour. Lateral colour leads to field-dependent systematic discrepancies of the topography data obtained from the envelope position of a low-coherence interference signal and the data resulting from its interference phase. Hence, an erroneous fringe order obtained from the envelope position leads to a 2π phase jump and thus to a so-called ghost step in the measured topography. Our first approach to solve this problem is based on the measurement of a surface standard of well-known geometry. By comparison of measurement results related to the envelope position and the phase of SWLI signals, the systematic error is estimated and a numerical error compensation method is proposed. Both experimental and simulation results confirm the validity of this numerical method. In addition, using an improved design of a white-light Michelson interferometer we demonstrate experimentally that lateral chromatic aberrations and dispersion influences can be reduced also in a physical way. In this context, a conventional long working distance microscope objective is used which was not originally designed for a Michelson interference microscope. (paper)

Optical refractometer based on an asymmetrical twin-core fiber Michelson interferometer.

Science.gov (United States)

Zhou, Ai; Zhang, Yanhui; Li, Guangping; Yang, Jun; Wang, Yuzhuo; Tian, Fengjun; Yuan, Libo

2011-08-15

We report and demonstrate an optical refractometer based on a compact fiber Michelson interferometer. The Michelson interferometer is composed of an asymmetrical twin-core fiber containing a central core and a side core. By chemically etching a segment of the twin-core fiber until the side core is exposed, the effective index of the side core in the etched region is sensitive to the environmental refractive index, which leads to a shift of the transmission spectrum of the Michelson interferometer. The experimental results show that such a device has a refractive index resolution of more than 800 nm/refractive index unit in the range of 1.34-1.37. © 2011 Optical Society of America

Verification of time-delay interferometry techniques using the University of Florida LISA interferometry simulator

Energy Technology Data Exchange (ETDEWEB)

Mitryk, Shawn J; Wand, Vinzenz; Mueller, Guido, E-mail: smitryk@phys.ufl.ed, E-mail: mueller@phys.ufl.ed [Department of Physics, University of Florida, PO Box 118440, Gainesville, FL 32611-8440 (United States)

2010-04-21

Laser Interferometer Space Antenna (LISA) is a cooperative NASA/ESA mission proposed to directly measure gravitational waves (GW) in the frequency range from 30 muHz to 1 Hz with an optimal strain sensitivity of 10{sup -21}/sq root(Hz) at 3 mHz. LISA will utilize a modified Michelson interferometer to measure length changes of 40 pm/sq root(Hz) between drag-free proof masses located on three separate spacecraft (SC) separated by a distance of 5 Gm. The University of Florida has developed a hardware-in-the-loop simulator of the LISA constellation to verify the laser noise cancellation technique known as time-delay interferometry (TDI). We replicate the frequency stabilization of the laser on the local SC and the phase-locking of the lasers on the far SC. The laser photodetector beatnotes are electronically delayed, Doppler shifted and applied with a mock GW signal to simulate the laser link between the SC. The beatnotes are also measured with a LISA-like phasemeter and the data are used to extract the laser phase and residual phase-lock loop noise in post-processing through TDI. This uncovers the GW modulation signal buried under the laser noise. The results are then compared to the requirements defined by the LISA science collaboration.

A Michelson interferometer for ultracold neutrons

International Nuclear Information System (INIS)

Steyerl, A.; Malik, S.S.; Steinhauser, K.A.; Berger, L.

1979-01-01

We propose a neutron Michelson Interferometer installed within a focussing 'gravity diffractometer' for ultracold neutrons. In this arrangement the expected interference pattern depends only on the well-defined vertical component of neutron wavevector. Possible applications of such an interferometer are discussed. (orig.)

Analysis of the localization of Michelson interferometer fringes using Fourier optics and temporal coherence

International Nuclear Information System (INIS)

Narayanamurthy, C S

2009-01-01

Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in Principles of Optics by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer have never been analysed seriously in any book. Because Michelson's interferometer is one of the important and fundamental optical experiments taught at both undergraduate and graduate levels, it would be appropriate to explain the localization of these fringes. In this paper, we analyse the localization of Michelson interferometer fringes using Fourier optics and temporal coherence, and show that they never localize at any plane even at infinity

Molecular spintronics using single-molecule magnets

Science.gov (United States)

Bogani, Lapo; Wernsdorfer, Wolfgang

2008-03-01

A revolution in electronics is in view, with the contemporary evolution of the two novel disciplines of spintronics and molecular electronics. A fundamental link between these two fields can be established using molecular magnetic materials and, in particular, single-molecule magnets. Here, we review the first progress in the resulting field, molecular spintronics, which will enable the manipulation of spin and charges in electronic devices containing one or more molecules. We discuss the advantages over more conventional materials, and the potential applications in information storage and processing. We also outline current challenges in the field, and propose convenient schemes to overcome them.

Spintronics of antiferromagnetic systems

International Nuclear Information System (INIS)

Gomonaj, E.V.; Loktev, V.M.

2014-01-01

Spintronics of antiferromagnetics is a new field that has developed in a fascinating research topic in physics of magnetism. Antiferromagnetics, like ferromagnetic materials experience the influence of spin-polarized current, even though they show no macroscopic magnetization. The mechanism of this phenomenon is related to spin-dependent interaction between free and localized electrons-sd-exchange. Due to the peculiarities of antiferromagnetic materials (complicated magnetic structure, essential role of the exchange interactions, lack of macroscopic magnetization) spintronics of antiferromagnets appeals to new theoretical and experimental approaches. The purpose of this review is to systemize and summarize the recent progress in this field. We start with a short introduction into the structure and dynamics of antiferromagnets and proceed with discussion of different microscopic and phenomenological theories for description of current-induced phenomena in ferro-/antiferromagnetic heterostructures. We also consider the problems of the reverse influence of antiferromagnetic ordering on current, and effectiveness of the fully antiferromagnetic spin valve. In addition, we shortly review and interpret the available experimental results.

Oxide materials for spintronic device applications

Science.gov (United States)

Prestgard, Megan Campbell

Spintronic devices are currently being researched as next-generation alternatives to traditional electronics. Electronics, which utilize the charge-carrying capabilities of electrons to store information, are fundamentally limited not only by size constraints, but also by limits on current flow and degradation, due to electro-migration. Spintronics devices are able to overcome these limitations, as their information storage is in the spin of electrons, rather than their charge. By using spin rather than charge, these current-limiting shortcomings can be easily overcome. However, for spintronic devices to be fully implemented into the current technology industry, their capabilities must be improved. Spintronic device operation relies on the movement and manipulation of spin-polarized electrons, in which there are three main processes that must be optimized in order to maximize device efficiencies. These spin-related processes are: the injection of spin-polarized electrons, the transport and manipulation of these carriers, and the detection of spin-polarized currents. In order to enhance the rate of spin-polarized injection, research has been focused on the use of alternative methods to enhance injection beyond that of a simple ferromagnetic metal/semiconductor injector interface. These alternatives include the use of oxide-based tunnel barriers and the modification of semiconductors and insulators for their use as ferromagnetic injector materials. The transport of spin-polarized carriers is heavily reliant on the optimization of materials' properties in order to enhance the carrier mobility and to quench spin-orbit coupling (SOC). However, a certain degree of SOC is necessary in order to allow for the electric-field, gate-controlled manipulation of spin currents. Spin detection can be performed via both optical and electrical techniques. Using electrical methods relies on the conversion between spin and charge currents via SOC and is often the preferred method for

EIT Based Gas Detector Design by Using Michelson Interferometer

International Nuclear Information System (INIS)

Abbasian, K.; Rostami, A.; Abdollahi, M. H.

2011-01-01

Electromagnetically induced transparency (EIT) is one of the interesting phenomena of light-matter interaction which modifies matter properties for propagation of light. In other words, we can change the absorption and refractive index (RI) in neighborhood of the resonant frequency using EIT. In this paper, we have doped 3-level quantum dots in one of the Michelson Interferometer's mirror and used EIT to change its RI. So, a controllable phase difference between lights in two arms of interferometer is created. Long response time is the main drawback of Michelson interferometer based sensor, which is resolved by this technique.

Bipolar spintronics: from spin injection to spin-controlled logic

International Nuclear Information System (INIS)

Zutic, Igor; Fabian, Jaroslav; Erwin, Steven C

2007-01-01

An impressive success of spintronic applications has been typically realized in metal-based structures which utilize magnetoresistive effects for substantial improvements in the performance of computer hard drives and magnetic random access memories. Correspondingly, the theoretical understanding of spin-polarized transport is usually limited to a metallic regime in a linear response, which, while providing a good description for data storage and magnetic memory devices, is not sufficient for signal processing and digital logic. In contrast, much less is known about possible applications of semiconductor-based spintronics and spin-polarized transport in related structures which could utilize strong intrinsic nonlinearities in current-voltage characteristics to implement spin-based logic. Here we discuss the challenges for realizing a particular class of structures in semiconductor spintronics: our proposal for bipolar spintronic devices in which carriers of both polarities (electrons and holes) contribute to spin-charge coupling. We formulate the theoretical framework for bipolar spin-polarized transport, and describe several novel effects in two- and three-terminal structures which arise from the interplay between nonequilibrium spin and equilibrium magnetization

CMOS-compatible spintronic devices: a review

Science.gov (United States)

Makarov, Alexander; Windbacher, Thomas; Sverdlov, Viktor; Selberherr, Siegfried

2016-11-01

For many decades CMOS devices have been successfully scaled down to achieve higher speed and increased performance of integrated circuits at lower cost. Today’s charge-based CMOS electronics encounters two major challenges: power dissipation and variability. Spintronics is a rapidly evolving research and development field, which offers a potential solution to these issues by introducing novel ‘more than Moore’ devices. Spin-based magnetoresistive random-access memory (MRAM) is already recognized as one of the most promising candidates for future universal memory. Magnetic tunnel junctions, the main elements of MRAM cells, can also be used to build logic-in-memory circuits with non-volatile storage elements on top of CMOS logic circuits, as well as versatile compact on-chip oscillators with low power consumption. We give an overview of CMOS-compatible spintronics applications. First, we present a brief introduction to the physical background considering such effects as magnetoresistance, spin-transfer torque (STT), spin Hall effect, and magnetoelectric effects. We continue with a comprehensive review of the state-of-the-art spintronic devices for memory applications (STT-MRAM, domain wall-motion MRAM, and spin-orbit torque MRAM), oscillators (spin torque oscillators and spin Hall nano-oscillators), logic (logic-in-memory, all-spin logic, and buffered magnetic logic gate grid), sensors, and random number generators. Devices with different types of resistivity switching are analyzed and compared, with their advantages highlighted and challenges revealed. CMOS-compatible spintronic devices are demonstrated beginning with predictive simulations, proceeding to their experimental confirmation and realization, and finalized by the current status of application in modern integrated systems and circuits. We conclude the review with an outlook, where we share our vision on the future applications of the prospective devices in the area.

A reconfigurable optofluidic Michelson interferometer using tunable droplet grating.

Science.gov (United States)

Chin, L K; Liu, A Q; Soh, Y C; Lim, C S; Lin, C L

2010-04-21

This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquids. The optofluidic Michelson interferometer is highly sensitive and is suitable for the measurement of biomedical and biochemical buffer solutions. The experimental results show that it has a sensitivity of 66.7 nm per refractive index unit (RIU) and a detection range of 0.086 RIU.

Michelson interferometer vibrometer using self-correcting synthetic-heterodyne demodulation.

Science.gov (United States)

Connelly, Michael J; Galeti, José Henrique; Kitano, Cláudio

2015-06-20

Synthetic-heterodyne demodulation is a useful technique for dynamic displacement and velocity detection in interferometric sensors, as it can provide an output signal that is immune to interferometric drift. With the advent of cost-effective, high-speed real-time signal-processing systems and software, processing of the complex signals encountered in interferometry has become more feasible. In synthetic heterodyne, to obtain the actual dynamic displacement or vibration of the object under test requires knowledge of the interferometer visibility and also the argument of two Bessel functions. In this paper, a method is described for determining the former and setting the Bessel function argument to a set value, which ensures maximum sensitivity. Conventional synthetic-heterodyne demodulation requires the use of two in-phase local oscillators; however, the relative phase of these oscillators relative to the interferometric signal is unknown. It is shown that, by using two additional quadrature local oscillators, a demodulated signal can be obtained that is independent of this phase difference. The experimental interferometer is a Michelson configuration using a visible single-mode laser, whose current is sinusoidally modulated at a frequency of 20 kHz. The detected interferometer output is acquired using a 250 kHz analog-to-digital converter and processed in real time. The system is used to measure the displacement sensitivity frequency response and linearity of a piezoelectric mirror shifter over a range of 500 Hz to 10 kHz. The experimental results show good agreement with two data-obtained independent techniques: the signal coincidence and denominated n-commuted Pernick method.

Prospect for antiferromagnetic spintronics

Czech Academy of Sciences Publication Activity Database

Martí, Xavier; Fina, I.; Jungwirth, Tomáš

2015-01-01

Roč. 51, č. 4 (2015), s. 2900104 ISSN 0018-9464 R&D Projects: GA MŠk(CZ) LM2011026; GA ČR GB14-37427G EU Projects: European Commission(XE) 268066 - 0MSPIN Institutional support: RVO:68378271 Keywords : spintronics * antiferromagnets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.277, year: 2015

An X-ray BBB Michelson interferometer.

Science.gov (United States)

Sutter, John P; Ishikawa, Tetsuya; Kuetgens, Ulrich; Materlik, Gerhard; Nishino, Yoshinori; Rostomyan, Armen; Tamasaku, Kenji; Yabashi, Makina

2004-09-01

A new X-ray Michelson interferometer based on the BBB interferometer of Bonse and Hart and designed for X-rays of wavelength approximately 1 A was described in a previous paper. Here, a further test carried out at the SPring-8 1 km beamline BL29XUL is reported. One of the BBB's mirrors was displaced by a piezo to introduce the required path-length difference. The resulting variation of intensity with piezo voltage as measured by an avalanche photodiode could be ascribed to the phase variation resulting from the path-length change, with a small additional contribution from the change of the position of the lattice planes of the front mirror relative to the rest of the crystal. This 'Michelson fringe' interpretation is supported by the observed steady movement across the output beam of the interference fringes produced by a refractive wedge when the piezo voltage was ramped. The front-mirror displacement required for one complete fringe at the given wavelength is only 0.675 A; therefore, a quiet environment is vital for operating this device, as previous experiments have shown.

Organic-based magnon spintronics

Science.gov (United States)

Liu, Haoliang; Zhang, Chuang; Malissa, Hans; Groesbeck, Matthew; Kavand, Marzieh; McLaughlin, Ryan; Jamali, Shirin; Hao, Jingjun; Sun, Dali; Davidson, Royce A.; Wojcik, Leonard; Miller, Joel S.; Boehme, Christoph; Vardeny, Z. Valy

2018-03-01

Magnonics concepts utilize spin-wave quanta (magnons) for information transmission, processing and storage. To convert information carried by magnons into an electric signal promises compatibility of magnonic devices with conventional electronic devices, that is, magnon spintronics1. Magnons in inorganic materials have been studied widely with respect to their generation2,3, transport4,5 and detection6. In contrast, resonant spin waves in the room-temperature organic-based ferrimagnet vanadium tetracyanoethylene (V(TCNE)x (x ≈ 2)), were detected only recently7. Herein we report room-temperature coherent magnon generation, transport and detection in films and devices based on V(TCNE)x using three different techniques, which include broadband ferromagnetic resonance (FMR), Brillouin light scattering (BLS) and spin pumping into a Pt adjacent layer. V(TCNE)x can be grown as neat films on a large variety of substrates, and it exhibits extremely low Gilbert damping comparable to that in yttrium iron garnet. Our studies establish an alternative use for organic-based magnets, which, because of their synthetic versatility, may substantially enrich the field of magnon spintronics.

Preliminary result of bunch length measurement using a modified Michelson interferometer

International Nuclear Information System (INIS)

Lin Xuling; Luo Feng; Bei Hua; Dai Zhimin; Chinese Academy of Sciences, Beijing; Zhang Jianbing; Lu Shanliang; Yu Tiemin

2009-01-01

Based on the femtosecond accelerator device which was built at the Shanghai Institute of Applied Physics (SINAP), recently a modified far infrared Michelson interferometer has been developed to measure the length of electron bunches via the optical autocorrelation method. Compared with our former normal Michelson interferometer, we use a hollow retroreflector instead of a flat mirror as the reflective mirror. The experimental setup and results of the bunch length measurement will be described in this paper. (authors)

AMI: Augmented Michelson Interferometer

Science.gov (United States)

Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

2015-10-01

Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

MO-AB-BRA-03: Calorimetry-Based Absorbed Dose to Water Measurements Using Interferometry

Energy Technology Data Exchange (ETDEWEB)

Flores-Martinez, E; Malin, M; DeWerd, L [University of WI-Madison/ADCL, Madison, WI (United States)

2015-06-15

Purpose: Interferometry-based calorimetry is a novel technique to measure radiation-induced temperature changes allowing the measurement of absorbed dose to water (ADW). There are no mechanical components in the field. This technique also has the possibility of obtaining 2D dose distributions. The goal of this investigation is to calorimetrically-measure doses between 2.5 and 5 Gy over a single projection in a photon beam using interferometry and compare the results with doses calculated using the TG-51 linac calibration. Methods: ADW was determined by measuring radiation-induced phase shifts (PSs) of light passing through water irradiated with a 6 MV photon beam. A 9×9×9 cm{sup 3} glass phantom filled with water and placed in an arm of a Michelson interferometer was irradiated with 300, 400, 500 and 600 monitor units. The whole system was thermally insulated to achieve sufficient passive temperature control. The depth of measurement was 4.5 cm with a field size of 7×7 cm{sup 2}. The intensity of the fringe pattern was monitored with a photodiode and used to calculate the time-dependent PS curve. Data was acquired 60 s before and after the irradiation. The radiation-induced PS was calculated by taking the difference in the pre- and post-irradiation drifts extrapolated to the midpoint of the irradiation. Results were compared to computed doses. Results: Average comparison of calculated ADW values with interferometry-measured values showed an agreement to within 9.5%. k=1 uncertainties were 4.3% for calculations and 14.7% for measurements. The dominant source of uncertainty for the measurements was a temperature drift of about 30 µK/s caused by heat conduction from the interferometer’s surroundings. Conclusion: This work presented the first absolute ADW measurements using interferometry in the dose range of linac-based radiotherapy. Future work to improve measurements’ reproducibility includes the implementation of active thermal control techniques.

Development of high resolution Michelson interferometer for stable phase-locked ultrashort pulse pair generation.

Science.gov (United States)

Okada, Takumi; Komori, Kazuhiro; Goshima, Keishiro; Yamauchi, Shohgo; Morohashi, Isao; Sugaya, Takeyoshi; Ogura, Mutsuo; Tsurumachi, Noriaki

2008-10-01

We developed a high resolution Michelson interferometer with a two-frequency He-Ne laser positioning system in order to stabilize the relative phase of a pulse pair. The control resolution corresponded to a 12 as time resolution or a phase of 1.5 degrees at 900 nm. This high resolution Michelson interferometer can generate a phase-locked pulse pair either with a specific relative phase such as 0 or pi radians or with an arbitrary phase. Coherent control of an InAs self-assembled quantum dot was demonstrated using the high resolution Michelson interferometer with a microspectroscopy system.

PREFACE International Symposium on Spintronic Devices and Commercialization 2010

Science.gov (United States)

Du, You-wei; Judy, Jack; Qian, Zhenghong; Wang, Jianping

2011-01-01

SSDC logo Preface The International Symposium on Spintronic Devices and Commercialization (ISSDC' 2010) was held in Beijing, China, from 21 to 24 October 2010. The aim of the symposium was to provide an opportunity for international experts, academics, researchers, practitioners and students working in the areas of spintronic theories, spintronic materials, and spintronic devices to exchange information on the R&D and commercialization of spintronic materials and devices. New developments, concepts, future research trends and potential commercialization areas were also discussed. The topics covered by ISSDC' 2010 were: Fundmental Spintronic Theories/Experiments Spin polarization, spin-dependent scattering, spin relaxation, spin manipulation and optimization, as well as other related characterizations and applications, etc. Spintronic Materials Giant magnetoresistance materials, magnetic tunnel junction materials, magnetic semiconductor materials, molecular spintronic materials. Spintronic Devices Sensors, isolators, spin logic devices and magnetic random access memories (MRAMs), microwave devices, spin diodes, spin transistor, spin filters and detectors, spin optoelectronic devices, spin quantum devices, single chip computer, spin molecule and single electron devices. Other Magnetic Materials Soft magnetic materials, hard magnetic materials, magneto-optical materials, magnetostriction materials. Applications of Spintronic Devices Magnetic position/angle/velocity/rotation velocity sensors, magnetic encoders, magnetic compasses, bio-medical magnetic devices and other applications. Future Research Trends and the Commercialization of Spintronic Devices Approximately 85 scientists from almost 10 countries participated in the conference. The conference featured 6 keynote lectures, 8 invited lectures, 12 contributed lectures and about 30 posters. We would like to express our gratitude to all participants for their presentations and discussions, which made the conference

Accessing High Spatial Resolution in Astronomy Using Interference Methods

Science.gov (United States)

Carbonel, Cyril; Grasset, Sébastien; Maysonnave, Jean

2018-01-01

In astronomy, methods such as direct imaging or interferometry-based techniques (Michelson stellar interferometry for example) are used for observations. A particular advantage of interferometry is that it permits greater spatial resolution compared to direct imaging with a single telescope, which is limited by diffraction owing to the aperture of…

Concepts of antiferromagnetic spintronics

Czech Academy of Sciences Publication Activity Database

Gomonay, O.; Jungwirth, Tomáš; Sinova, Jairo

2017-01-01

Roč. 11, č. 4 (2017), 1-8, č. článku 1700022. ISSN 1862-6254 R&D Projects: GA MŠk LM2015087; GA ČR GB14-37427G Institutional support: RVO:68378271 Keywords : spintronics * antiferromagnets Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.032, year: 2016

Algorithms for Unequal-Arm Michelson Interferometers

Science.gov (United States)

Giampieri, Giacomo; Hellings, Ronald W.; Tinto, Massimo; Bender, Peter L.; Faller, James E.

1994-01-01

A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam.

Analysis of the Localization of Michelson Interferometer Fringes Using Fourier Optics and Temporal Coherence

Science.gov (United States)

Narayanamurthy, C. S.

2009-01-01

Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in "Principles of Optics" by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer…

Fiscal 2000 pioneering research on the spintronic device basic technology; 2000 nendo spintronic soshi kiban gijutsu sendo kenkyu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Researchers specializing in technologies of magnetism or semiconductor were drafted from the industrial, official, and academic circles, who conducted hearings, patent investigations, overseas surveys, and the like, concerning spintronics. Collected in this report are the outline of the research and development of spintronic device technology, its current state and tasks and its importance from social and economic viewpoints, and the strategy that Japan should follow in the research and development of the technology. Important spintronic device technologies now attracting attention are mentioned below. The nonvolatile magnetic memory device MRAM (magnetic random access memory) is supposed to be the device which will enjoy practical application first among like devices. It is expected that the spin conduction device will lead to novel functions when the possibilities of the spin-dependent electric conduction phenomenon are further pursued. It is hoped that the spin optical device will be used as a light isolator, light spin logic device, field induced variable wavelength laser device, spin laser device, high-speed light switch, and so forth. It is necessary to watch the development of a spin-aided quantum computer which is still at the stage of basic study. (NEDO)

Michelson interferometer with diffractively-coupled arm resonators in second-order Littrow configuration.

Science.gov (United States)

Britzger, Michael; Wimmer, Maximilian H; Khalaidovski, Alexander; Friedrich, Daniel; Kroker, Stefanie; Brückner, Frank; Kley, Ernst-Bernhard; Tünnermann, Andreas; Danzmann, Karsten; Schnabel, Roman

2012-11-05

Michelson-type laser-interferometric gravitational-wave (GW) observatories employ very high light powers as well as transmissively-coupled Fabry-Perot arm resonators in order to realize high measurement sensitivities. Due to the absorption in the transmissive optics, high powers lead to thermal lensing and hence to thermal distortions of the laser beam profile, which sets a limit on the maximal light power employable in GW observatories. Here, we propose and realize a Michelson-type laser interferometer with arm resonators whose coupling components are all-reflective second-order Littrow gratings. In principle such gratings allow high finesse values of the resonators but avoid bulk transmission of the laser light and thus the corresponding thermal beam distortion. The gratings used have three diffraction orders, which leads to the creation of a second signal port. We theoretically analyze the signal response of the proposed topology and show that it is equivalent to a conventional Michelson-type interferometer. In our proof-of-principle experiment we generated phase-modulation signals inside the arm resonators and detected them simultaneously at the two signal ports. The sum signal was shown to be equivalent to a single-output-port Michelson interferometer with transmissively-coupled arm cavities, taking into account optical loss. The proposed and demonstrated topology is a possible approach for future all-reflective GW observatory designs.

Graphene-based spintronic components

OpenAIRE

Zeng, Minggang; Shen, Lei; Su, Haibin; Zhou, Miao; Zhang, Chun; Feng, Yuanping

2010-01-01

A major challenge of spintronics is in generating, controlling and detecting spin-polarized current. Manipulation of spin-polarized current, in particular, is difficult. We demonstrate here, based on calculated transport properties of graphene nanoribbons, that nearly +-100% spin-polarized current can be generated in zigzag graphene nanoribbons (ZGNRs) and tuned by a source-drain voltage in the bipolar spin diode, in addition to magnetic configurations of the electrodes. This unusual transpor...

Silicon spintronics with ferromagnetic tunnel devices

International Nuclear Information System (INIS)

Jansen, R; Sharma, S; Dash, S P; Min, B C

2012-01-01

In silicon spintronics, the unique qualities of ferromagnetic materials are combined with those of silicon, aiming at creating an alternative, energy-efficient information technology in which digital data are represented by the orientation of the electron spin. Here we review the cornerstones of silicon spintronics, namely the creation, detection and manipulation of spin polarization in silicon. Ferromagnetic tunnel contacts are the key elements and provide a robust and viable approach to induce and probe spins in silicon, at room temperature. We describe the basic physics of spin tunneling into silicon, the spin-transport devices, the materials aspects and engineering of the magnetic tunnel contacts, and discuss important quantities such as the magnitude of the spin accumulation and the spin lifetime in the silicon. We highlight key experimental achievements and recent progress in the development of a spin-based information technology. (topical review)

Measurement of Refractive Index Using a Michelson Interferometer.

Science.gov (United States)

Fendley, J. J.

1982-01-01

Describes a novel and simple method of measuring the refractive index of transparent plates using a Michelson interferometer. Since it is necessary to use a computer program when determining the refractive index, undergraduates could be given the opportunity of writing their own programs. (Author/JN)

Q-switched operation with Fox-Smith-Michelson laser cavity

International Nuclear Information System (INIS)

Huang, X; Huang, L; Gong, M

2008-01-01

A new kind of three-mirror composite cavity, Fox-Smith-Michelson cavity has been configured. This laser cavity is capable of high power output, owing to the low threshold of Michelson cavity. Also, thanks to the mode selection function of Fox-Smith cavity, stable pulses at high repetition rate can be generated. In our experiment, 15.54 W CW output at 1064 nm has been achieved, with an optic-to-optic conversion efficiency of 42.2%. At the Q-switching repetition rate of 100 kHz, the average output power is 11.92 W, with an optic-to-optic conversion efficiency of 38.2%. For Q-switching frequency from 30 kHz to 100 kHz, the pulse width variation is below 4.4% and the amplitude variation is below 4.8%

Development of stable monolithic wide-field Michelson interferometers.

Science.gov (United States)

Wan, Xiaoke; Ge, Jian; Chen, Zhiping

2011-07-20

Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations. © 2011 Optical Society of America

Compensation of non-ideal beam splitter polarization distortion effect in Michelson interferometer

Science.gov (United States)

Liu, Yeng-Cheng; Lo, Yu-Lung; Liao, Chia-Chi

2016-02-01

A composite optical structure consisting of two quarter-wave plates and a single half-wave plate is proposed for compensating for the polarization distortion induced by a non-ideal beam splitter in a Michelson interferometer. In the proposed approach, the optimal orientations of the optical components within the polarization compensator are determined using a genetic algorithm (GA) such that the beam splitter can be treated as a free-space medium and modeled using a unit Mueller matrix accordingly. Two implementations of the proposed polarization controller are presented. In the first case, the compensator is placed in the output arm of Michelson interferometer such that the state of polarization of the interfered output light is equal to that of the input light. However, in this configuration, the polarization effects induced by the beam splitter in the two arms of the interferometer structure cannot be separately addressed. Consequently, in the second case, compensator structures are placed in the Michelson interferometer for compensation on both the scanning and reference beams. The practical feasibility of the proposed approach is introduced by considering a Mueller polarization-sensitive (PS) optical coherence tomography (OCT) structure with three polarization controllers in the input, reference and sample arms, respectively. In general, the results presented in this study show that the proposed polarization controller provides an effective and experimentally-straightforward means of compensating for the polarization distortion effects induced by the non-ideal beam splitters in Michelson interferometers and Mueller PS-OCT structures.

Plasma flow velocity measurements using a modulated Michelson interferometer

International Nuclear Information System (INIS)

Howard, J.

1997-01-01

This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (orig.)

Quantitative Phase Determination by Using a Michelson Interferometer

Science.gov (United States)

Pomarico, Juan A.; Molina, Pablo F.; D'Angelo, Cristian

2007-01-01

The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as…

Thermoluminescence spectra measured with a Michelson interferometer

International Nuclear Information System (INIS)

Haschberger, P.

1991-01-01

A Michelson interferometer was redesigned to prove its capabilities in the measurement of short-lived, low-intensity thermoluminescence spectra. Interferograms are collected during heating up the thermoluminescent probe in a heater plate. A personal computer controls the data acquisition and processes the Fourier transform. As the results show, even a comparatively simple and limited setup leads to relevant and reproducible spectra. (author)

Spintronics in nanoscale devices

CERN Document Server

Hedin, Eric R

2013-01-01

By exploiting the novel properties of quantum dots and nanoscale Aharonov-Bohm rings together with the electronic and magnetic properties of various semiconductor materials and graphene, researchers have conducted numerous theoretical and computational modeling studies and experimental tests that show promising behavior for spintronics applications. Spin polarization and spin-filtering capabilities and the ability to manipulate the electron spin state through external magnetic or electric fields have demonstrated the promise of workable nanoscale devices for computing and memory applications.

Spintronic logic design methodology based on spin Hall effect–driven magnetic tunnel junctions

International Nuclear Information System (INIS)

Kang, Wang; Zhang, Youguang; Zhao, Weisheng; Wang, Zhaohao; Klein, Jacques-Olivier; Lv, Weifeng

2016-01-01

Conventional complementary metal-oxide-semiconductor (CMOS) technology is now approaching its physical scaling limits to enable Moore’s law to continue. Spintronic devices, as one of the potential alternatives, show great promise to replace CMOS technology for next-generation low-power integrated circuits in nanoscale technology nodes. Until now, spintronic memory has been successfully commercialized. However spintronic logic still faces many critical challenges (e.g. direct cascading capability and small operation gain) before it can be practically applied. In this paper, we propose a standard complimentary spintronic logic (CSL) design methodology to form a CMOS-like logic design paradigm. Using the spin Hall effect (SHE)-driven magnetic tunnel junction (MTJ) device as an example, we demonstrate CSL implementation, functionality and performance. This logic family provides a unified design methodology for spintronic logic circuits and partly solves the challenges of direct cascading capability and small operation gain in the previously proposed spintronic logic designs. By solving a modified Landau–Lifshitz–Gilbert equation, the magnetization dynamics in the free layer of the MTJ is theoretically described and a compact electrical model is developed. With this electrical model, numerical simulations have been performed to evaluate the functionality and performance of the proposed CSL design. Simulation results demonstrate that the proposed CSL design paradigm is rather promising for low-power logic computing. (paper)

On the path toward organic spintronics

NARCIS (Netherlands)

Moodera, J.S.; Koopmans, B.; Oppeneer, P.M.

2014-01-01

Organic materials provide a unique platform for exploiting the spin of the electron—a field dubbed organic spintronics. Originally, this was mostly motivated by the notion that because of weak spin-orbit coupling, due to the small mass elements in organics and small hyperfine field coupling, organic

Enlarging the angle of view in Michelson-interferometer-based shearography by embedding a 4f system.

Science.gov (United States)

Wu, Sijin; He, Xiaoyuan; Yang, Lianxiang

2011-07-20

Digital shearography based on Michelson interferometers suffers from the disadvantage of a small angle of view due to the structure. We demonstrate a novel digital shearography system with a large angle of view. In the optical arrangement, the imaging lens is in front of the Michelson interferometer rather than behind it as in traditional digital shearography. Thus, the angle of view is no longer limited by the Michelson interferometer. The images transmitting between the separate lens and camera are accomplished by a 4f system in the new style of shearography. The influences of the 4f system on shearography are also discussed. © 2011 Optical Society of America

Tunable Magnetic Resonance in Microwave Spintronics Devices

Science.gov (United States)

Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.

2015-01-01

Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe based tunable microwave spintronics devices, which is 10X higher than conventional methods.

Advances in graphene spintronics

Science.gov (United States)

van Wees, Bart

I will give an overview of the status of graphene spintronics, from both scientific as technological perspectives. In the introduction I will show that (single) layer graphene is the ideal host for electronic spins, allowing spin transport by diffusion over distances exceeding 20 micrometers at room temperature. I will show how by the use of carrier drift, induced by charge currents, effective spin relaxation lengths of 90 micrometer can be obtained in graphene encapsulated between boron-nitride layers. This also allows the controlled flow and guiding of spin currents, opening new avenues for spin logic devices based on lateral architectures. By preparing graphene on top of a ferromagnetic insulator (yttrium iron garnet (YIG)) we have shown that we can induce an exchange interaction in the graphene, thus effectively making the graphene magnetic. This allows for new ways to induce and control spin precession for new applications. Finally I will show how, by using two-layer BN tunnel barriers, spins can be injected from a ferromagnet into graphene with a spin polarization which can be tuned continuously from -80% to 40%, using a bias range from -0.3V to 0.3V across the barrier. These unique record values of the spin polarization are not yet understood, but they highlight the potential of Van der Waals stacking of graphene and related 2D materials for spintronics.

Guided magnonic Michelson interferometer.

Science.gov (United States)

Ahmed, Muhammad H; Jeske, Jan; Greentree, Andrew D

2017-01-30

Magnonics is an emerging field with potential applications in classical and quantum information processing. Freely propagating magnons in two-dimensional media are subject to dispersion, which limits their effective range and utility as information carriers. We show the design of a confining magnonic waveguide created by two surface current carrying wires placed above a spin-sheet, which can be used as a primitive for reconfigurable magnonic circuitry. We theoretically demonstrate the ability of such guides to counter the transverse dispersion of the magnon in a spin-sheet, thus extending the range of the magnon. A design of a magnonic directional coupler and controllable Michelson interferometer is shown, demonstrating its utility for information processing tasks.

Plasma flow velocity measurements using a modulated Michelson interferometer

NARCIS (Netherlands)

Howard, J.; Meijer, F. G.

1997-01-01

This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (C) 1997 Elsevier Science S.A.

Novel method to measure the soil clay’s permeability by laser interferometry

Directory of Open Access Journals (Sweden)

Asselman H.

2014-04-01

Full Text Available In this study, we’ll present a new method to measure the permeability of clay soils (or infiltration rate by laser interferometry. The device is a modified Michelson interferometer. Indeed on the movable mirror is glued a clay sample in the form of a parallelepiped, dried, of length L, height H and shaped to retain the drops of water on its surface to control water’s content .When injecting a volume of distilled water (a few drops to the surface of the sample, it swells and moves the mirror, then we can measure the swelling depending on the depth of a clay soil and its permeability. Therefore we measure time that takes water to reach a depth of Z and we determine the infiltration rate: V=6μm/s ± 3% in concordance with literal values included between 2,8 and 13,9μm/s in clayey silt. For this comparison, we used the study of the characterization of the clay fraction to our sample by XRD.

Perspective: Ultrafast magnetism and THz spintronics

Energy Technology Data Exchange (ETDEWEB)

Walowski, Jakob; Münzenberg, Markus [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

2016-10-14

This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time, this milestone work by Bigot and coworkers gave insight directly into the time scales of microscopic interactions that connect the spin and electron system. While intense discussions in the field were fueled by the complexity of the processes in the past, it now became evident that it is a puzzle of many different parts. Rather than providing an overview that has been presented in previous reviews on ultrafast processes in ferromagnets, this perspective will show that with our current depth of knowledge the first applications are developed: THz spintronics and all-optical spin manipulation are becoming more and more feasible. The aim of this perspective is to point out where we can connect the different puzzle pieces of understanding gathered over 20 years to develop novel applications. Based on many observations in a large number of experiments. Differences in the theoretical models arise from the localized and delocalized nature of ferromagnetism. Transport effects are intrinsically non-local in spintronic devices and at interfaces. We review the need for multiscale modeling to address the processes starting from electronic excitation of the spin system on the picometer length scale and sub-femtosecond time scale, to spin wave generation, and towards the modeling of ultrafast phase transitions that altogether determine the response time of the ferromagnetic system. Today, our current understanding gives rise to the first usage of ultrafast spin physics for ultrafast magnetism control: THz spintronic devices. This makes the field of ultrafast spin-dynamics an emerging topic open for many researchers right now.

Perspective: Ultrafast magnetism and THz spintronics

International Nuclear Information System (INIS)

Walowski, Jakob; Münzenberg, Markus

2016-01-01

This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time, this milestone work by Bigot and coworkers gave insight directly into the time scales of microscopic interactions that connect the spin and electron system. While intense discussions in the field were fueled by the complexity of the processes in the past, it now became evident that it is a puzzle of many different parts. Rather than providing an overview that has been presented in previous reviews on ultrafast processes in ferromagnets, this perspective will show that with our current depth of knowledge the first applications are developed: THz spintronics and all-optical spin manipulation are becoming more and more feasible. The aim of this perspective is to point out where we can connect the different puzzle pieces of understanding gathered over 20 years to develop novel applications. Based on many observations in a large number of experiments. Differences in the theoretical models arise from the localized and delocalized nature of ferromagnetism. Transport effects are intrinsically non-local in spintronic devices and at interfaces. We review the need for multiscale modeling to address the processes starting from electronic excitation of the spin system on the picometer length scale and sub-femtosecond time scale, to spin wave generation, and towards the modeling of ultrafast phase transitions that altogether determine the response time of the ferromagnetic system. Today, our current understanding gives rise to the first usage of ultrafast spin physics for ultrafast magnetism control: THz spintronic devices. This makes the field of ultrafast spin-dynamics an emerging topic open for many researchers right now.

A wave optics approach to the theory of the Michelson-Morley experiment

Science.gov (United States)

Smid, Thomas

2017-11-01

A consistent classical wave optics approach to the theory of the Michelson-Morley experiment shows that the original theory as applied by Michelson and Morley and others does not calculate the optical paths of the two beams correctly, primarily because of incorrectly assuming a right angle reflection in the instrument’s reference frame for the transverse beam, but also because of the incorrect assumption of aberration for the wave fronts. The theory presented in this work proves the expected variation of the phase difference when rotating the interferometer to be more than twice as large and also strongly asymmetrical around the zero line.

Special Heusler compounds for spintronic applications

Energy Technology Data Exchange (ETDEWEB)

Balke, B.

2007-07-01

This work emphasizes the potential of Heusler compounds in a wide range of spintronic applications. Using electronic structure calculations it is possible to design compounds for specific applications. Examples for GMR and TMR applications, for spin injection into semiconductors, and for spin torque transfer applications will be shown. After a detailed introduction about spintronics and related materials chapter 5 reports about the investigation of new half-metallic compounds where the Fermi energy is tuned in the middle of the gap to result in more stable compounds for GMR and TMR applications. The bulk properties of the quaternary Heusler alloy Co{sub 2}Mn{sub 1-x}Fe{sub x}Si with the Fe concentration ranging from x=0 to 1 are reported and the results suggest that the best candidate for applications may be found at an iron concentration of about 50%. Due to the effect that in the Co{sub 2}Mn{sub 1-x}Fe{sub x}Si series the transition metal carrying the localized moment is exchanged and this might lead to unexpected effects on the magnetic properties if the samples are not completely homogeneous chapter 6 reports about the optimization of the Heusler compounds for GMR and TMR applications. The structural and magnetic properties of the quaternary Heusler alloy Co{sub 2}FeAl{sub 1-x}Si{sub x} with varying Si concentration are reported. From the combination of experimental (better order for high Si content) and theoretical findings (robust gap at x=0.5) it is concluded that a compound with an intermediate Si concentration close to x=0.5-0.7 would be best suited for spintronic applications, especially for GMR and TMR applications. In chapter 7 the detailed investigation of compounds for spin injection into semiconductors is reported. It is shown that the diluted magnetic semiconductors based on CoTiSb with a very low lattice mismatch among each other are interesting materials for spintronics applications like Spin-LEDs or other spin injection devices. Chapter 8 refers

Nanospintronics: when spintronics meets single electron physics

International Nuclear Information System (INIS)

Seneor, Pierre; Bernand-Mantel, Anne; Petroff, Frederic

2007-01-01

As spintronics goes nano, new phenomena are predicted resulting from the interplay between spin dependent transport and single electron physics. The long term goal of manipulating spins one by one would open a promising path to quantum computing. Towards this end, there is an ever-growing effort to connect spin tanks (i.e. ferromagnetic leads) to smaller and smaller objects in order to study spintronics in reduced dimensions. As the dimensions are reduced, spin dependent transport is predicted to interplay with quantum and/or single electron charging effects. We review experiments and theories on the interplay between Coulomb blockade and spin properties (namely magneto-Coulomb effects) in structures where a single nano-object is connected to ferromagnetic leads. We then discuss briefly future directions in the emerging field of nanospintronics towards quantum dots, carbon nanotubes and single molecule magnets

Nonlinear Michelson interferometer for improved quantum metrology

OpenAIRE

Luis, Alfredo; Rivas, Ángel

2015-01-01

We examine quantum detection via a Michelson interferometer embedded in a gas with Kerr nonlinearity. This nonlinear interferometer is illuminated by pulses of classical light. This strategy combines the robustness against practical imperfections of classical light with the improvement provided by nonlinear processes. Regarding ultimate quantum limits, we stress that, as a difference with linear schemes, the nonlinearity introduces pulse duration as a new variable into play along with the ene...

Determination of refractive indices of biconvex lenses by use of a Michelson interferometer.

Science.gov (United States)

Chhaniwal, Vani K; Anand, Arun; Narayanamurthy, C S

2006-06-10

Measurements of lens parameters such as focal length, radius of curvature, and refractive index are important. We describe a measurement method that utilizes a Michelson interferometer to determine parameters of thin, convex lenses. The real fringe system formed by a Michelson interferometer is used to determine the focal lengths and the radii of curvature of the lenses. The refractive index of the lens material is determined from the thin-lens formula. We were able to determine the refractive indices to an accuracy as great as 99.97%. A detailed theoretical and experimental analysis is given.

Double-grating interferometer with a one-to-one correspondence with a Michelson interferometer.

Science.gov (United States)

Xu, Yande; Sasaki, Osami; Suzuki, Takamasa

2003-10-01

We describe a double-grating interferometer that has a one-to-one correspondence with a Michelson interferometer. The half spatial periods of the gratings are equivalent to the wavelengths of the interferometer. The widths of the interference fringes can be changed easily. The intensity distribution of the interference pattern is independent of the wavelength of the light source used. The surface profile of an object can be measured because two interference beams can coincide precisely on the image plane of the object. The measuring range is much larger than that of a Michelson interferometer.

Mariner 9 Michelson interferometer.

Science.gov (United States)

Hanel, R.; Schlachman, B.; Rodgers, D.; Breihan, E.; Bywaters, R.; Chapman, F.; Rhodes, M.; Vanous, D.

1972-01-01

The Michelson interferometer on Mariner 9 measures the thermal emission spectrum of Mars between 200 and 2000 per cm (between 5 and 50 microns) with a spectral resolution of 2.4 per cm in the apodized mode. A noise equivalent radiance of 0.5 x 10 to the minus 7th W/sq cm/ster/cm is deduced from data recorded in orbit around Mars. The Mariner interferometer deviates in design from the Nimbus 3 and 4 interferometers in several areas, notably, by a cesium iodide beam splitter and certain aspects of the digital information processing. Special attention has been given to the problem of external vibration. The instrument performance is demonstrated by calibration data and samples of Mars spectra.

Comment on The Rise of Semiconductor Spintronics

OpenAIRE

Korenev, Vladimir L.

2009-01-01

I argue that most of the key experiments that have born semiconductor spintronics were done and published earlier than the papers cited in the Nature Physics, 4 S20 (2008) milestone article (http://www.nature.com/milestones/spin, milestone 23).

Optical interferometry in astronomy

International Nuclear Information System (INIS)

Monnier, John D

2003-01-01

Here I review the current state of the field of optical stellar interferometry, concentrating on ground-based work although a brief report of space interferometry missions is included. We pause both to reflect on decades of immense progress in the field as well as to prepare for a new generation of large interferometers just now being commissioned (most notably, the CHARA, Keck and VLT Interferometers). First, this review summarizes the basic principles behind stellar interferometry needed by the lay-physicist and general astronomer to understand the scientific potential as well as technical challenges of interferometry. Next, the basic design principles of practical interferometers are discussed, using the experience of past and existing facilities to illustrate important points. Here there is significant discussion of current trends in the field, including the new facilities under construction and advanced technologies being debuted. This decade has seen the influence of stellar interferometry extend beyond classical regimes of stellar diameters and binary orbits to new areas such as mapping the accretion discs around young stars, novel calibration of the cepheid period-luminosity relation, and imaging of stellar surfaces. The third section is devoted to the major scientific results from interferometry, grouped into natural categories reflecting these current developments. Lastly, I consider the future of interferometry, highlighting the kinds of new science promised by the interferometers coming on-line in the next few years. I also discuss the longer-term future of optical interferometry, including the prospects for space interferometry and the possibilities of large-scale ground-based projects. Critical technological developments are still needed to make these projects attractive and affordable

Effect of external magnetic field on locking range of spintronic feedback nano oscillator

Science.gov (United States)

Singh, Hanuman; Konishi, K.; Bose, A.; Bhuktare, S.; Miwa, S.; Fukushima, A.; Yakushiji, K.; Yuasa, S.; Kubota, H.; Suzuki, Y.; Tulapurkar, A. A.

2018-05-01

In this work we have studied the effect of external applied magnetic field on the locking range of spintronic feedback nano oscillator. Injection locking of spintronic feedback nano oscillator at integer and fractional multiple of its auto oscillation frequency was demonstrated recently. Here we show that the locking range increases with increasing external magnetic field. We also show synchronization of spintronic feedback nano oscillator at integer (n=1,2,3) multiples of auto oscillation frequency and side band peaks at higher external magnetic field values. We have verified experimental results with macro-spin simulation using similar conditions as used for the experimental study.

Spintronics

International Nuclear Information System (INIS)

Grundler, Dirk

2003-01-01

Devices that exploit the spin of the electron promise to revolutionize microelectronics once polarized electrons can be injected efficiently into semiconductors at room temperature. Later this year physicists will be celebrating the centenary of Paul Dirac's birth. One of the most influential scientists of the 20th century, Dirac combined quantum mechanics and special relativity to explain the strange magnetic or 'spin' properties of the electron. What Dirac could not have foreseen, however, is how the spin of the electron could change the field of microelectronics. Indeed, the spin of the electron has attracted renewed interest recently because it promises a wide variety of new devices that combine logic, storage and sensor applications. Moreover, these 'Spintronics' devices might lead to quantum computers and quantum communication based on electronic solid-state devices, thus changing the perspective of information technology in the 21st century. Since the 1970s conventional electronic microprocessors have operated by shuttling packets of electronic charge along ever-smaller semiconductor channels. Although this trend will continue for the next few years, experts predict that silicon technology is beginning to approach fundamental limits. By 2008, for example, the width of the 'gate electrodes' in a silicon microprocessor will be just 45 nano metres across, which will place severe demands on the materials and manufacturing techniques used in the semiconductor industry. Indeed, the cost of implementing a new production line for such devices is predicted to reach $33bn. Although successors to silicon technology have been discussed, most of them rely on a complete set of new materials, new handling and processing techniques, and altered circuit design, among other developments. These new technologies include single-electron transistors and molecular-electronic devices based on organic materials or carbon nanotubes (see Carbon nanotubes roll on Physics World June

Kaon interferometry

International Nuclear Information System (INIS)

Roldao, C.G.; Padula, S.S.

1994-01-01

Preliminary results of the χ 2 analysis where data on kaon interferometry, obtained from the E859 Collaboration of the AGS/Brookhaven Nat.Lab., are compared with results of a hadronic resonance production model are presented. The main goal is to test the resolution power of the method here discussed when applied to the two-dimensional kaon interferometry

A new phase-shift microscope designed for high accuracy stitching interferometry

International Nuclear Information System (INIS)

Thomasset, Muriel; Idir, Mourad; Polack, François; Bray, Michael; Servant, Jean-Jacques

2013-01-01

Characterizing nanofocusing X-ray mirrors for the soon coming nano-imaging beamlines of synchrotron light sources motivates the development of new instruments with improved performances. The sensitivity and accuracy goal is now fixed well under the nm level and, at the same time, the spatial frequency range of the measurement should be pushed toward 50 mm −1 . SOLEIL synchrotron facility has therefore undertaken to equip with an interferential microscope suitable for stitching interferometry at this performance level. In order to keep control on the whole metrology chain it was decided to build a custom instrument in partnership with two small optics companies EOTECH and MBO. The new instrument is a Michelson micro-interferometer equipped with a custom-designed telecentric objective. It achieves the large depth of focus suitable for performing reliable calibrations and measurements. The concept has been validated with a predevelopment set-up, delivered in July 2010, which showed a static repeatability below 1 nm PV despite a non-thermally stabilized environment. The final instrument was delivered early this year and was installed inside SOLEIL's controlled environment facility, where thorough characterization tests are under way. Latest test results and first stitching measurements are presented

"Magnon Spintronics"

Science.gov (United States)

Yu, Haiming; Xiao, Jiang; Pirro, Philipp

2018-03-01

We are proud to present a collection of 12 cutting-edge research articles on the emerging field "magnon spintronics" investigating the properties of spin waves or magnons towards their potential applications in low-power-consumption information technologies. Magnons (quasiparticles of spin waves) are collective excitations of magnetizations in a magnetic system. The concept for such excitations was first introduced 1930 by Felix Bloch [1] who described ferromagnetism in a lattice. The field of magnon spintronics [2] or magnonics [3] aims at utilizing magnons to realize information processing and storage. The propagation of spin waves is free of charge transport, hence a successful realization of magnonic devices can innately avoid Joule heating induced energy loss in nowadays micro- or nano-electronic devices. Magnonics has made many progresses in recent years, including the demonstration of magnonic logic devices [4]. Towards the aim to generate magnonic devices, it is an essential step to find materials suitable for conveying spin waves. One outstanding candidate is a ferromagnetic insulator yttrium iron garnet (YIG). It offers an out standing low damping which allows the propagation of spin waves over relatively long distances. Experiments on such a thin YIG film with an out-of-plane magnetization have been performed by Chen et al. [5]. They excited so called forward volume mode spin waves and determined the propagating spin wave properties, such as the group velocities. Lohman et al. [6] has successfully imaged the propagating spin waves using time-resolved MOKE microscopy and show agreement with micromagnetic modellings. For very long time, YIG is the most ideal material for spin waves thanks to its ultra-low damping. However, it remains a major challenge integrate YIG on to Silicon substrate. Magnetic Heusler alloys on the other hand, can be easily grown on Si substrate and also shows reasonably good damping properties, which allow spin waves to propagate

Detection method of nonlinearity errors by statistical signal analysis in heterodyne Michelson interferometer.

Science.gov (United States)

Hu, Juju; Hu, Haijiang; Ji, Yinghua

2010-03-15

Periodic nonlinearity that ranges from tens of nanometers to a few nanometers in heterodyne interferometer limits its use in high accuracy measurement. A novel method is studied to detect the nonlinearity errors based on the electrical subdivision and the analysis method of statistical signal in heterodyne Michelson interferometer. Under the movement of micropositioning platform with the uniform velocity, the method can detect the nonlinearity errors by using the regression analysis and Jackknife estimation. Based on the analysis of the simulations, the method can estimate the influence of nonlinearity errors and other noises for the dimensions measurement in heterodyne Michelson interferometer.

Effect of external magnetic field on locking range of spintronic feedback nano oscillator

Directory of Open Access Journals (Sweden)

Hanuman Singh

2018-05-01

Full Text Available In this work we have studied the effect of external applied magnetic field on the locking range of spintronic feedback nano oscillator. Injection locking of spintronic feedback nano oscillator at integer and fractional multiple of its auto oscillation frequency was demonstrated recently. Here we show that the locking range increases with increasing external magnetic field. We also show synchronization of spintronic feedback nano oscillator at integer (n=1,2,3 multiples of auto oscillation frequency and side band peaks at higher external magnetic field values. We have verified experimental results with macro-spin simulation using similar conditions as used for the experimental study.

Quantitative phase determination by using a Michelson interferometer

International Nuclear Information System (INIS)

Pomarico, Juan A; Molina, Pablo F; Angelo, Cristian D'

2007-01-01

The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as refractive index, wavelength, optical thickness, etc. Generally speaking, most of the measurements are carried out by determining phase distortions through the changes in the location and/or shape of the interference fringes. However, the extreme sensitivity of this tool, for which minimum deviations of the conditions of its branches can cause very large modifications in the fringe pattern, makes phase changes difficult to follow and measure. The purpose of this communication is to show that, under certain conditions, the sensitivity of the Michelson interferometer can be 'turned down' allowing the quantitative measurement of phase changes with relative ease. As an example we present how the angle (or, optionally, the refractive index) of a transparent standard optical wedge can be determined. Experimental results are shown and compared with the data provided by the manufacturer showing very good agreement

Integration of spintronic interface for nanomagnetic arrays

Directory of Open Access Journals (Sweden)

Andrew Lyle

2011-12-01

Full Text Available An experimental demonstration utilizing a spintronic input/output (I/O interface for arrays of closely spaced nanomagnets is presented. The free layers of magnetic tunnel junctions (MTJs form dipole coupled nanomagnet arrays which can be applied to different contexts including Magnetic Quantum Cellular Automata (MQCA for logic applications and self-biased devices for field sensing applications. Dipole coupled nanomagnet arrays demonstrate adaptability to a variety of contexts due to the ability for tuning of magnetic response. Spintronics allows individual nanomagnets to be manipulated with spin transfer torque and monitored with magnetoresistance. This facilitates measurement of the magnetic coupling which is important for (yet to be demonstrated data propagation reliability studies. In addition, the same magnetic coupling can be tuned to reduce coercivity for field sensing. Dipole coupled nanomagnet arrays have the potential to be thousands of times more energy efficient than CMOS technology for logic applications, and they also have the potential to form multi-axis field sensors.

Adaptive Optics, LLLFT Interferometry, Astronomy

National Research Council Canada - National Science Library

2002-01-01

We propose to build a three telescope Michelson optical interferometer equipped with wavefront compensation technology as a demonstration and test bed for high resolution Deep Space Surveillance (DSS) and Astronomy...

The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

Science.gov (United States)

Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

2010-01-01

The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

Time delay interferometry with moving spacecraft arrays

International Nuclear Information System (INIS)

Tinto, Massimo; Estabrook, F.B.; Armstrong, J.W.

2004-01-01

Space-borne interferometric gravitational wave detectors, sensitive in the low-frequency (millihertz) band, will fly in the next decade. In these detectors the spacecraft-to-spacecraft light-travel-times will necessarily be unequal, time varying, and (due to aberration) have different time delays on up and down links. The reduction of data from moving interferometric laser arrays in solar orbit will in fact encounter nonsymmetric up- and down-link light time differences that are about 100 times larger than has previously been recognized. The time-delay interferometry (TDI) technique uses knowledge of these delays to cancel the otherwise dominant laser phase noise and yields a variety of data combinations sensitive to gravitational waves. Under the assumption that the (different) up- and down-link time delays are constant, we derive the TDI expressions for those combinations that rely only on four interspacecraft phase measurements. We then turn to the general problem that encompasses time dependence of the light-travel times along the laser links. By introducing a set of noncommuting time-delay operators, we show that there exists a quite general procedure for deriving generalized TDI combinations that account for the effects of time dependence of the arms. By applying our approach we are able to re-derive the 'flex-free' expression for the unequal-arm Michelson combinations X 1 , and obtain the generalized expressions for the TDI combinations called relay, beacon, monitor, and symmetric Sagnac

System analysis of a tilted field-widened Michelson interferometer for high spectral resolution lidar.

Science.gov (United States)

Liu, Dong; Hostetler, Chris; Miller, Ian; Cook, Anthony; Hair, Johnathan

2012-01-16

High spectral resolution lidars (HSRLs) have shown great value in aircraft aerosol remote sensing application and are planned for future satellite missions. A compact, robust, quasi-monolithic tilted field-widened Michelson interferometer is being developed as the spectral discrimination filter for an second-generation HSRL(HSRL-2) at NASA Langley Research Center. The Michelson interferometer consists of a cubic beam splitter, a solid arm and an air arm. Piezo stacks connect the air arm mirror to the body of the interferometer and can tune the interferometer within a small range. The whole interferometer is tilted so that the standard Michelson output and the reflected complementary output can both be obtained. In this paper, the transmission ratio is proposed to evaluate the performance of the spectral filter for HSRL. The transmission ratios over different types of system imperfections, such as cumulative wavefront error, locking error, reflectance of the beam splitter and anti-reflection coatings, system tilt, and depolarization angle are analyzed. The requirements of each imperfection for good interferometer performance are obtained.

Landau-Zener-Stueckelberg interferometry

Energy Technology Data Exchange (ETDEWEB)

Shevchenko, S.N., E-mail: sshevchenko@ilt.kharkov.u [B.Verkin Institute for Low Temperature Physics and Engineering, Kharkov (Ukraine); RIKEN Advanced Science Institute, Wako-shi, Saitama (Japan); Ashhab, S.; Nori, Franco [RIKEN Advanced Science Institute, Wako-shi, Saitama (Japan); Department of Physics, The University of Michigan, Ann Arbor, MI (United States)

2010-07-15

A transition between energy levels at an avoided crossing is known as a Landau-Zener transition. When a two-level system (TLS) is subject to periodic driving with sufficiently large amplitude, a sequence of transitions occurs. The phase accumulated between transitions (commonly known as the Stueckelberg phase) may result in constructive or destructive interference. Accordingly, the physical observables of the system exhibit periodic dependence on the various system parameters. This phenomenon is often referred to as Landau-Zener-Stueckelberg (LZS) interferometry. Phenomena related to LZS interferometry occur in a variety of physical systems. In particular, recent experiments on LZS interferometry in superconducting TLSs (qubits) have demonstrated the potential for using this kind of interferometry as an effective tool for obtaining the parameters characterizing the TLS as well as its interaction with the control fields and with the environment. Furthermore, strong driving could allow for fast and reliable control of the quantum system. Here we review recent experimental results on LZS interferometry, and we present related theory.

Landau-Zener-Stueckelberg interferometry

International Nuclear Information System (INIS)

Shevchenko, S.N.; Ashhab, S.; Nori, Franco

2010-01-01

A transition between energy levels at an avoided crossing is known as a Landau-Zener transition. When a two-level system (TLS) is subject to periodic driving with sufficiently large amplitude, a sequence of transitions occurs. The phase accumulated between transitions (commonly known as the Stueckelberg phase) may result in constructive or destructive interference. Accordingly, the physical observables of the system exhibit periodic dependence on the various system parameters. This phenomenon is often referred to as Landau-Zener-Stueckelberg (LZS) interferometry. Phenomena related to LZS interferometry occur in a variety of physical systems. In particular, recent experiments on LZS interferometry in superconducting TLSs (qubits) have demonstrated the potential for using this kind of interferometry as an effective tool for obtaining the parameters characterizing the TLS as well as its interaction with the control fields and with the environment. Furthermore, strong driving could allow for fast and reliable control of the quantum system. Here we review recent experimental results on LZS interferometry, and we present related theory.

Multiple reflection Michelson interferometer with picometer resolution.

Science.gov (United States)

Pisani, Marco

2008-12-22

A Michelson interferometer based on an optical set-up allowing multiple reflection between two plane mirrors performs the multiplication of the optical path by a factor N, proportionally increasing the resolution of the measurement. A multiplication factor of almost two orders of magnitude has been demonstrated with a simple set-up. The technique can be applied to any interferometric measurement where the classical interferometer limits due to fringe nonlinearities and quantum noise are an issue. Applications in precision engineering, vibration analysis, nanometrology, and spectroscopy are foreseen.

Michelson Interferometer (MINT)

Science.gov (United States)

Lacis, Andrew; Carlson, Barbara

1993-01-01

MINT is a Michelson interferometer designed to measure the thermal emission from the earth at high spectral resolution (2/cm) over a broad spectral range (250-1700/cm, 6-40 mu m) with contiguous 3-pixel wide (12 mrad, 8 km field of view) along-track sampling. MINT is particularly well suited for monitoring cloud properties (cloud cover, effective temperature, optical thickness, ice/water phase, and effective particle size) both day and night, as well as tropospheric water vapor, ozone, and temperature. The key instrument characteristics that make MINT ideally suited for decadal monitoring purposes are: high wavelength to wavelength precision across the full IR spectrum with high spectral resolution; space-proven long-term durability and calibration stability; and small size, low cost, low risk instrument incorporating the latest detector and electronics technology. MINT also incorporates simplicity in design and operation by utilizing passively cooled DTGS detectors and nadir viewing geometry (with target motion compensation). MINT measurement objectives, instrument characteristics, and key advantages are summarized in this paper.

Spin-polarized transport properties of a pyridinium-based molecular spintronics device

Science.gov (United States)

Zhang, J.; Xu, B.; Qin, Z.

2018-05-01

By applying a first-principles approach based on non-equilibrium Green's functions combined with density functional theory, the transport properties of a pyridinium-based "radical-π-radical" molecular spintronics device are investigated. The obvious negative differential resistance (NDR) and spin current polarization (SCP) effect, and abnormal magnetoresistance (MR) are obtained. Orbital reconstruction is responsible for novel transport properties such as that the MR increases with bias and then decreases and that the NDR being present for both parallel and antiparallel magnetization configurations, which may have future applications in the field of molecular spintronics.

2. Interferometry and polarimetry. 2.1. Principle of interferometry and polarimetry

International Nuclear Information System (INIS)

Kawahata, Kazuo; Okajima, Shigeki

2000-01-01

Laser interferometry and polarimetry are useful diagnostics for measuring electron density and the internal magnetic field distribution in the plasma. In this section, principles of interferometry and polarimetry and their applications to plasma diagnostics on LHD (section 2.2) and JT-60 (section 2.3) are descried. (author)

Spatio-temporal phase retrieval in speckle interferometry with Hilbert transform and two-dimensional phase unwrapping

Science.gov (United States)

Li, Xiangyu; Huang, Zhanhua; Zhu, Meng; He, Jin; Zhang, Hao

2014-12-01

Hilbert transform (HT) is widely used in temporal speckle pattern interferometry, but errors from low modulations might propagate and corrupt the calculated phase. A spatio-temporal method for phase retrieval using temporal HT and spatial phase unwrapping is presented. In time domain, the wrapped phase difference between the initial and current states is directly determined by using HT. To avoid the influence of the low modulation intensity, the phase information between the two states is ignored. As a result, the phase unwrapping is shifted from time domain to space domain. A phase unwrapping algorithm based on discrete cosine transform is adopted by taking advantage of the information in adjacent pixels. An experiment is carried out with a Michelson-type interferometer to study the out-of-plane deformation field. High quality whole-field phase distribution maps with different fringe densities are obtained. Under the experimental conditions, the maximum number of fringes resolvable in a 416×416 frame is 30, which indicates a 15λ deformation along the direction of loading.

Michelson mode selector for spectral range stabilization in a self-sweeping fiber laser.

Science.gov (United States)

Tkachenko, A Yu; Vladimirskaya, A D; Lobach, I A; Kablukov, S I

2018-04-01

We report on spectral range stabilization in a self-sweeping laser by adding a narrowband fiber Bragg grating (FBG) to the output mirror in the Michelson configuration. The effects of FBG reflectivity and optical path difference in the Michelson interferometer on the laser spectral dynamics are investigated. Optimization of the interferometer allows us to demonstrate broadband (over 16 nm) self-sweeping operation and reduction of the start and stop wavelength fluctuations by two orders and one order of magnitude (∼100 and 15 times) for start and stop bounds, respectively (down to several picometers). The proposed approaches significantly improve quality of the spectral dynamics and facilitate application of the self-sweeping lasers.

Neuromorphic computing with nanoscale spintronic oscillators.

Science.gov (United States)

Torrejon, Jacob; Riou, Mathieu; Araujo, Flavio Abreu; Tsunegi, Sumito; Khalsa, Guru; Querlioz, Damien; Bortolotti, Paolo; Cros, Vincent; Yakushiji, Kay; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Stiles, Mark D; Grollier, Julie

2017-07-26

Neurons in the brain behave as nonlinear oscillators, which develop rhythmic activity and interact to process information. Taking inspiration from this behaviour to realize high-density, low-power neuromorphic computing will require very large numbers of nanoscale nonlinear oscillators. A simple estimation indicates that to fit 10 8 oscillators organized in a two-dimensional array inside a chip the size of a thumb, the lateral dimension of each oscillator must be smaller than one micrometre. However, nanoscale devices tend to be noisy and to lack the stability that is required to process data in a reliable way. For this reason, despite multiple theoretical proposals and several candidates, including memristive and superconducting oscillators, a proof of concept of neuromorphic computing using nanoscale oscillators has yet to be demonstrated. Here we show experimentally that a nanoscale spintronic oscillator (a magnetic tunnel junction) can be used to achieve spoken-digit recognition with an accuracy similar to that of state-of-the-art neural networks. We also determine the regime of magnetization dynamics that leads to the greatest performance. These results, combined with the ability of the spintronic oscillators to interact with each other, and their long lifetime and low energy consumption, open up a path to fast, parallel, on-chip computation based on networks of oscillators.

Experimental demonstration of a variable reflectivity signal recycled Michelson interferometer for gravitational wave detection

International Nuclear Information System (INIS)

De Vine, G.; Shaddock, D.; McClelland, D.

2002-01-01

Full text: One technique of improving the sensitivity of interferometric gravitational wave detectors is to implement a signal mirror. This involves placing a mirror at the output of the Michelson interferometer. The gravitational wave signal is then 'recycled' back into the interferometer where it can coherently add with the gravitational wave signal still being produced. The frequency of the improved sensitivity is dependent on the position of the signal mirror, while the peak height and bandwidth are dependent on the reflectivity of the signal mirror. This is because the signal mirror forms a cavity with the Michelson interferometer and this cavity has a resonant frequency dependent on its length and a bandwidth dependent on its finesse, which are a function of signal mirror position and reflectivity, respectively. Due to the varying and/or unknown nature of the gravitational wave frequencies and wave-forms, it is desirable to be able to control both the peak frequency and bandwidth of the detector. The peak frequency can be easily adjusted by altering the signal mirror position. The bandwidth, however, is fixed with the signal mirror reflectivity. In a long base-line gravitational wave detector it is impractical to swap the signal mirror with one of different reflectivity for a number of reasons, for example, the detector's high vacuum would have to be broken, realignment performed and locking re-acquired. This is addressed by the proposal of two different forms of variable reflectivity signal mirror (VRSM): a Fabry-Perot cavity and a Michelson interferometer. These are analysed and the reasons for choosing to investigate the Michelson VRSM are given. The reasons include the potential for easier control and the smooth variation in reflectivity with arm length difference. The experiment is discussed and the results of the first demonstration of variable reflectivity signal recycling are presented in the form of frequency responses obtained by injecting a second

Naturally stable Sagnac-Michelson nonlinear interferometer.

Science.gov (United States)

Lukens, Joseph M; Peters, Nicholas A; Pooser, Raphael C

2016-12-01

Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing-conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9% interference visibility and find evidence for noise reduction based on phase-sensitive gain. Our configuration utilizes fewer components than previous demonstrations and requires no active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.

Space Interferometry Science Working Group

Science.gov (United States)

Ridgway, Stephen T.

1992-12-01

Decisions taken by the astronomy and astrophysics survey committee and the interferometry panel which lead to the formation of the Space Interferometry Science Working Group (SISWG) are outlined. The SISWG was formed by the NASA astrophysics division to provide scientific and technical input from the community in planning for space interferometry and in support of an Astrometric Interferometry Mission (AIM). The AIM program hopes to measure the positions of astronomical objects with a precision of a few millionths of an arcsecond. The SISWG science and technical teams are described and the outcomes of its first meeting are given.

Design of a Michelson Interferometer for Quantitative Refraction Index Profile Measurements

NARCIS (Netherlands)

Nijholt, J.L.M.

1998-01-01

This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much

Cold neutron interferometry and its application. 2. Coherency and cold neutron spin interferometry

International Nuclear Information System (INIS)

Achiwa, Norio; Ebisawa, Toru

1998-03-01

The second workshop entitled 'Interference studies and cold neutron spin interferometry' was held on 10 and 11 March 1998 at KUR (Kyoto University Research Reactor Institute, Kumatori). Cold neutron spin interferometry is a new field. So it is very important for its development to learn the studies of X-ray and neutron optics which are rapidly developing with long history. In the workshop, the issues related to interference were reviewed such as experimental studies on cold neutron spin interferometry, theoretical and experimental approach on tunneling time, interference experiments by neutrons and its application, interference studies using synchrotron radiation, topics on silicon interferometry and quantum measurement problem and cold neutron interference experiment related to quantum measurement problem. The 8 of the presented papers are indexed individually. (J.P.N.)

Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement

International Nuclear Information System (INIS)

Le Floch, Sebastien; Salvade, Yves; Droz, Nathalie; Mitouassiwou, Rostand; Favre, Patrick

2010-01-01

We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of ± 50 μm for a 1 ms acquisition time.

Fiber inline Michelson interferometer fabricated by a femtosecond laser.

Science.gov (United States)

Yuan, Lei; Wei, Tao; Han, Qun; Wang, Hanzheng; Huang, Jie; Jiang, Lan; Xiao, Hai

2012-11-01

A fiber inline Michelson interferometer was fabricated by micromachining a step structure at the tip of a single-mode optical fiber using a femtosecond laser. The step structure splits the fiber core into two reflection paths and produces an interference signal. A fringe visibility of 18 dB was achieved. Temperature sensing up to 1000°C was demonstrated using the fabricated assembly-free device.

Two-photon quantum interference in a Michelson interferometer

International Nuclear Information System (INIS)

Odate, Satoru; Wang Haibo; Kobayashi, Takayoshi

2005-01-01

We have observed two-photon quantum interference in a Michelson interferometer. For the first time, we experimentally demonstrated two-photon quantum interference patterns, which show the transition from nonsubwavelength interference fringes to the general subwavelength interference. At the same time, a photon bunching effect was also shown by a postselection. The |1, 1> state with a single photon in a mode corresponding to each arm of the interferometer was exclusively postselected by using path difference between two arms

Quantum computing and spintronics

International Nuclear Information System (INIS)

Kantser, V.

2007-01-01

Tentative to build a computer, which can operate according to the quantum laws, has leaded to concept of quantum computing algorithms and hardware. In this review we highlight recent developments which point the way to quantum computing on the basis solid state nanostructures after some general considerations concerning quantum information science and introducing a set of basic requirements for any quantum computer proposal. One of the major direction of research on the way to quantum computing is to exploit the spin (in addition to the orbital) degree of freedom of the electron, giving birth to the field of spintronics. We address some semiconductor approach based on spin orbit coupling in semiconductor nanostructures. (authors)

Principles of Stellar Interferometry

CERN Document Server

Glindemann, Andreas

2011-01-01

Over the last decade, stellar interferometry has developed from a specialist tool to a mainstream observing technique, attracting scientists whose research benefits from milliarcsecond angular resolution. Stellar interferometry has become part of the astronomer’s toolbox, complementing single-telescope observations by providing unique capabilities that will advance astronomical research. This carefully written book is intended to provide a solid understanding of the principles of stellar interferometry to students starting an astronomical research project in this field or to develop instruments and to astronomers using interferometry but who are not interferometrists per se. Illustrated by excellent drawings and calculated graphs the imaging process in stellar interferometers is explained starting from first principles on light propagation and diffraction wave propagation through turbulence is described in detail using Kolmogorov statistics the impact of turbulence on the imaging process is discussed both f...

Interferometry with polarised neutrons

International Nuclear Information System (INIS)

Badurek, G.

1978-01-01

This paper aimed to give an outline of what might be expected from an extension of polarized beam techniques in neutron interferometry and how it could be achieved properly and what is the present state of this special field of interferometry

Fringe Benefits of Interferometry

Indian Academy of Sciences (India)

It was Michelson whocarried out this programme and made the first direct measurementof the giant star Betelguse in the constellation ofOrion. His value for the angular diameter, 47 milliarcsecondsor 2.6×10−7 radians, was completely confirmed by laterwork following his methods. The key concept introduced was.

Magnon spintronics in non-collinear magnetic insulator/metal heterostructures

NARCIS (Netherlands)

Aqeel, Aisha

2017-01-01

The research presented in this thesis focuses on the growth of complex magnetic materials with unique magnetic properties and experimental investigation of fundamental spintronics phenomena in these magnetic insulators with magnetic orders varying from collinear to noncollinear chiral spin

Study on the wide-angle Michelson interferometer with large air gap.

Science.gov (United States)

Gao, Haiyang; Tang, Yuanhe; Hua, Dengxin; Liu, Hanchen

2011-10-10

A wide-angle Michelson interferometer with large air gap is proposed to effectively reduce the size of the glass arms and constraint on material. It provides a novel and practical instrument for ground based wind measurement of the upper atmosphere. The field widening conditions for the large air gap are calculated in theory. For the five spectral lines of 557.7 nm, 630.0 nm, 732.0 nm, 834.6 nm, and 865.7 nm, the optimal results under ideal condition are obtained with air gaps of 1.0 cm, 1.5 cm, and 2.0 cm, respectively. With the fixed optical path difference (OPD) of 7.495 cm, three pairs of glass arms are optimized. The pair with length of 1.5 cm for air gap, 5.765 cm for H-ZF12, and 2.956 cm for H-ZLaF54, has better effect of field widening than the other two pairs and its OPD variation is only within 0.30 wavelengths at incident angle of 3°. For developing a more practical wide-angle Michelson interferometer, the H-K9L glass with size of 4.445 cm is employed as the arm material of solid interferometer. The experiment for field of view of 3° is designed and the data processing and analysis for 60 images show the agreement between experimental results and theoretical simulation. The OPD variations are only within 0.27 wavelengths for image edge. The feasibility and practicality of the wide-angle Michelson interferometer with large air gap is proved by means of theory and experiment. © 2011 Optical Society of America

A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber

International Nuclear Information System (INIS)

Frazão, O; Silva, S F; Viegas, J; Baptista, J M; Santos, J L; Roy, P

2010-01-01

A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber is demonstrated. The hybrid interferometer presents three waves. Two parallel Fabry–Perot cavities with low finesse are formed between the splice region and the end of a dual-core microstructured fiber. A Michelson configuration is obtained by the two small cores of the microstructured fiber. The spectral response of the hybrid interferometer presents two pattern fringes with different frequencies due to the respective optical path interferometers. The hybrid interferometer was characterized in strain and temperature presenting different sensitivity coefficients for each topology. Due to these characteristics, this novel sensing head is able to measure strain and temperature, simultaneously

Synthesis and characterization of transition-metal-doped zinc oxide nanocrystals for spintronics

Science.gov (United States)

Wang, Xuefeng

Spintronics (spin transport electr onics), in which both spin and charge of carriers are utilized for information processing, is believed to challenge the current microelectronics and to become the next-generation electronics. Nanostructured spintronic materials and their synthetic methodologies are of paramount importance for manufacturing future nanoscale spintronic devices. This thesis aims at studying synthesis, characterization, and magnetism of transition-metal-doped zinc oxide (ZnO) nanocrystals---a diluted magnetic semiconductor (DMS)---for potential applications in future nano-spintronics. A simple bottom-up-based synthetic strategy named a solvothermal technique is introduced as the primary synthetic approach and its crystal growth mechanism is scrutinized. N-type cobalt-doped ZnO-based DMS nanocrystals are employed as a model system, and characterized by a broad spectrum of advanced microscopic and spectroscopic techniques. It is found that the self-orientation growth mechanism, imperfect oriented attachment, is intimately correlated with the high-temperature ferromagnetism via defects. The influence of processing on the magnetic properties, such as compositional variations, reaction conditions, and post-growth treatment, is also studied. In this way, an in-depth understanding of processing-structure-property interrelationships and origins of magnetism in DMS nanocrystals are obtained in light of the theoretical framework of a spin-split impurity band model. In addition, a nanoscale spinodal decomposition phase model is also briefly discussed. Following the similar synthetic route, copper- and manganese-doped ZnO nanocrystals have been synthesized and characterized. They both show high-temperature ferromagnetism in line with the aforementioned theoretical model(s). Moreover, they display interesting exchange biasing phenomena at low temperatures, revealing the complexity of magnetic phases therein. The crystal growth strategy demonstrated in this work

Interferometry

Science.gov (United States)

Totzeck, Michael

The intention of this chapter is to provide a fast and comprehensive overview of the principles of interferometry and the various types of interferometer, including interferogram evaluation and applications. Due to the age and the importance of the subject, you can find a number of monographs [16.1,2,3,4] and book chapters [16.5] in the literature. The number of original papers on optical interferometry is far too large to even attempt complete coverage in this chapter. Whenever possible, review papers are cited. Original papers are cited according to their aptness as starting points into the subject. This, however, reflects my personal judgment. Even if you do not share my opinion, you should find the references therein useful.

Simple Ultra-Low-Cost Undergraduate Holography Using a Modified Michelson Interferometer.

Science.gov (United States)

Rudmin, J. W.; And Others

1980-01-01

A technique is presented for producing holograms using equipment which is already in the possesion of the majority of college physics departments, which includes a slightly modified Michelson interferometer, a helium-neon laser, and a long focal-length lens. Production of high quality holograms has been achieved by inexperienced undergraduates…

Measurement of two-dimensional Doppler wind fields using a field widened Michelson interferometer.

Science.gov (United States)

Langille, Jeffery A; Ward, William E; Scott, Alan; Arsenault, Dennis L

2013-03-10

An implementation of the field widened Michelson concept has been applied to obtain high resolution two-dimensional (2D) images of low velocity (interferometer scanning mirror position is controlled to subangstrom precision with subnanometer repeatability using the multi-application low-voltage piezoelectric instrument control electronics developed by COM DEV Ltd.; it is the first implementation of this system as a phase stepping Michelson. In this paper the calibration and characterization of the Doppler imaging system is described and the planned implementation of this new technique for imaging 2D wind and irradiance fields using the earth's airglow is introduced. Observations of Doppler winds produced by a rotating wheel are reported and shown to be of sufficient precision for buoyancy wave observations in airglow in the mesopause region of the terrestrial atmosphere.

Infrared spectra of lunar soils. [using a Michelson interferometer

Science.gov (United States)

Aronson, J. R.; Emslie, A. G.; Smith, E. M.

1979-01-01

Measured data obtained by Michelson interferometer spectrometer were stored in a computer file and smoothed by being passed forward and backward through a digital four-pole low pass filter. Infrared spectra of the 10 lunar samples are presented in the format of brightness temperature versus frequency. The mol % of feldspar, pyroxene, olivine, ilmenite and ferromagnetic silicate in each sample is presented in tables. The reflectance spectra of ilmenite and enstatite are shown in graphs.

Spintronic materials and devices based on antiferromagnetic metals

Directory of Open Access Journals (Sweden)

Y.Y. Wang

2017-04-01

Full Text Available In this paper, we review our recent experimental developments on antiferromagnet (AFM spintronics mainly comprising Mn-based noncollinear AFM metals. IrMn-based tunnel junctions and Hall devices have been investigated to explore the manipulation of AFM moments by magnetic fields, ferromagnetic materials and electric fields. Room-temperature tunneling anisotropic magnetoresistance based on IrMn as well as FeMn has been successfully achieved, and electrical control of the AFM exchange spring is realized by adopting ionic liquid. In addition, promising spin-orbit effects in AFM as well as spin transfer via AFM spin waves reported by different groups have also been reviewed, indicating that the AFM can serve as an efficient spin current source. To explore the crucial role of AFM acting as efficient generators, transmitters, and detectors of spin currents is an emerging topic in the field of magnetism today. AFM metals are now ready to join the rapidly developing fields of basic and applied spintronics, enriching this area of solid-state physics and microelectronics.

Power-recycled michelson interferometer with a 50/50 grating beam splitter

International Nuclear Information System (INIS)

Friedrich, D; Burmeister, O; Britzger, M; Bunkowski, A; Danzmann, K; Schnabel, R; Clausnitzer, T; Fahr, S; Kley, E-B; Tuennermann, A

2008-01-01

We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about F PR ∼ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed

Power-recycled michelson interferometer with a 50/50 grating beam splitter

OpenAIRE

Friedrich, Daniel; Burmeister, O.; Britzger, M.; Bunkowski, A.; Clausnitzer, T.; Fahr, S.; Kley, E.B.; Tünnermann, A.; Danzmann, Karsten; Schnabel, Roman

2008-01-01

We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about FPR ≈ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed.

Semiconductors put spin in spintronics

International Nuclear Information System (INIS)

Weiss, Dieter

2000-01-01

Electrons and holes, which carry the current in semiconductor devices, are quantum-mechanical objects characterized by a set of quantum numbers - the band index, the wave-vector (which is closely related to the electron or hole velocity) and spin. The spin, however, is one of the strangest properties of particles. In simple terms, we can think of the spin as an internal rotation of the electron, but it has no classical counterpart. The spin is connected to a quantized magnetic moment and hence acts as a microscopic magnet. Thus the electron spin can adopt one of two directions (''up'' or ''down'') in a magnetic field. The spin plays no role in conventional electronics and the current in any semiconductor device is made up of a mixture of electrons with randomly oriented spins. However, a new range of electronic devices that transport the spin of the electrons, in addition to their charge, is being developed. But the biggest obstacle to making practical ''spin electronic'' or ''spintronic'' devices so far has been finding a way of injecting spin-polarized electrons or holes into the semiconductor and then detecting them. Recently a team of physicists from the University of Wuerzburg in Germany, and also a collaboration of researchers from Tohoku University in Japan and the University of California at Santa Barbara, have found a way round these problems using either semi-magnetic or ferromagnetic semiconductors as ''spin aligners'' (R Fiederling et al. 1999 Nature 402 787; Y Ohno et al. 1999 Nature 402 790). In this article the author presents the latest breakthrough in spintronics research. (UK)

Magnetization switching schemes for nanoscale three-terminal spintronics devices

Science.gov (United States)

Fukami, Shunsuke; Ohno, Hideo

2017-08-01

Utilizing spintronics-based nonvolatile memories in integrated circuits offers a promising approach to realize ultralow-power and high-performance electronics. While two-terminal devices with spin-transfer torque switching have been extensively developed nowadays, there has been a growing interest in devices with a three-terminal structure. Of primary importance for applications is the efficient manipulation of magnetization, corresponding to information writing, in nanoscale devices. Here we review the studies of current-induced domain wall motion and spin-orbit torque-induced switching, which can be applied to the write operation of nanoscale three-terminal spintronics devices. For domain wall motion, the size dependence of device properties down to less than 20 nm will be shown and the underlying mechanism behind the results will be discussed. For spin-orbit torque-induced switching, factors governing the threshold current density and strategies to reduce it will be discussed. A proof-of-concept demonstration of artificial intelligence using an analog spin-orbit torque device will also be reviewed.

Hybrid Spintronic Structures With Magnetic Oxides and Heusler Alloys

DEFF Research Database (Denmark)

Xu, Y. B.; Hassan, S. S. A.; Wong, P. K. J.

2008-01-01

Hybrid spintronic structures, integrating half-metallic magnetic oxides and Heusler alloys with their predicted high spin polarization, are important for the development of second-generation spintronics with high-efficient spin injection. We have synthesized epitaxial magnetic oxide Fe3O4 on Ga......As(100) and the unit cell of the Fe3O4 was found to be rotated by 45 degrees to match the gallium arsenide GaAs. The films were found to have a bulk-like moment down to 3-4 nm and a low coercivity indicating a high-quality magnetic interface. The magnetization hysteresis loops of the ultrathin films...... are controlled by uniaxial magnetic anisotropy. The dynamic response of the sample shows a heavily damped precessional response to the applied field pulses. In the Heusler alloy system of Co-2 MnGa on GaAs, we found that the magnetic moment was reduced for thicknesses down to 10 nm, which may account...

Analysis of a four-mirror-cavity enhanced Michelson interferometer.

Science.gov (United States)

Thüring, André; Lück, Harald; Danzmann, Karsten

2005-12-01

We investigate the shot-noise-limited sensitivity of a four-mirror-cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature gives boundary conditions allowing systematic parameter studies.

Special relativity and the Michelson-Morley experiment

International Nuclear Information System (INIS)

Chapman, B.R.

1979-01-01

It is stated that contrary to most textbook statements about the origins of relativity, there is no real evidence to support the existence of a causal relationship between Michelson's 'crucial' experiment on ether drift and Einstein's enunciation of special relativity. Selective but, it is believed by the author, representative evidence elating to the genesis of the theory of special relativity is presented. Since this evidence contradicts both the substance and the spirit of most textbook references to that genesis, it is thought by the author to have some pedagogic significance for those attempting to teach both the process and the content of physics. (U.K.)

Unequal-Arms Michelson Interferometers

Science.gov (United States)

Tinto, Massimo; Armstrong, J. W.

2000-01-01

Michelson interferometers allow phase measurements many orders of magnitude below the phase stability of the laser light injected into their two almost equal-length arms. If, however, the two arms are unequal, the laser fluctuations can not be removed by simply recombining the two beams. This is because the laser jitters experience different time delays in the two arms, and therefore can not cancel at the photo detector. We present here a method for achieving exact laser noise cancellation, even in an unequal-arm interferometer. The method presented in this paper requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. By linearly combining the two data sets with themselves, after they have been properly time shifted, we show that it is possible to construct a new data set that is free of laser fluctuations. An application of this technique to future planned space-based laser interferometer detector3 of gravitational radiation is discussed.

Precision measurement with atom interferometry

International Nuclear Information System (INIS)

Wang Jin

2015-01-01

Development of atom interferometry and its application in precision measurement are reviewed in this paper. The principle, features and the implementation of atom interferometers are introduced, the recent progress of precision measurement with atom interferometry, including determination of gravitational constant and fine structure constant, measurement of gravity, gravity gradient and rotation, test of weak equivalence principle, proposal of gravitational wave detection, and measurement of quadratic Zeeman shift are reviewed in detail. Determination of gravitational redshift, new definition of kilogram, and measurement of weak force with atom interferometry are also briefly introduced. (topical review)

Comparing Laser Interferometry and Atom Interferometry Approaches to Space-Based Gravitational-Wave Measurement

Science.gov (United States)

Baker, John; Thorpe, Ira

2012-01-01

Thoroughly studied classic space-based gravitational-wave missions concepts such as the Laser Interferometer Space Antenna (LISA) are based on laser-interferometry techniques. Ongoing developments in atom-interferometry techniques have spurred recently proposed alternative mission concepts. These different approaches can be understood on a common footing. We present an comparative analysis of how each type of instrument responds to some of the noise sources which may limiting gravitational-wave mission concepts. Sensitivity to laser frequency instability is essentially the same for either approach. Spacecraft acceleration reference stability sensitivities are different, allowing smaller spacecraft separations in the atom interferometry approach, but acceleration noise requirements are nonetheless similar. Each approach has distinct additional measurement noise issues.

Topological insulator materials and nanostructures for future electronics, spintronics and energy conversion

International Nuclear Information System (INIS)

Kantser, Valeriu

2011-01-01

Two fundamental electrons attributes in materials and nanostructures - charge and spin - determine their electronic properties. The processing of information in conventional electronic devices is based only on the charge of the electrons. Spin electronics, or spintronics, uses the spin of electrons, as well as their charge, to process information. Metals, semiconductors and insulators are the basic materials that constitute the components of electronic devices, and these have been transforming all aspects of society for over a century. In contrast, magnetic metals, half-metals, magnetic semiconductors, dilute magnetic semiconductors and magnetic insulators are the materials that will form the basis for spintronic devices. Materials with topological band structure attributes and having a zero-energy band gap surface states are a special class of these materials that exhibit some fascinating and superior electronic properties compared to conventional materials allowing to combine both charge and spin functionalities. This article reviews a range of topological insulator materials and nanostructures with tunable surface states, focusing on nanolayered and nanowire like structures. These materials and nanostructures all have intriguing physical properties and numerous potential practical applications in spintronics, electronics, optics and sensors.

Phase correction for a Michelson interferometer with misaligned mirrors

Science.gov (United States)

Goorvitch, D.

1975-01-01

The phase correction for a Michelson interferometer with misaligned mirrors in converging light is shown to give rise to a quadratic phase shift. In general, the calculation of a spectrum from the measured interferogram needs phase correction. Phase corrections have been well worked out for the cases of a linear phase shift and a phase that is slowly varying. The standard procedures for correcting calculated spectra need to be modified, however, to remove any phase errors resulting from misaligned mirrors.

Astronomical Observations by Speckle Interferometry.

Science.gov (United States)

1986-06-12

commonly -been noted [Heintz (101)] that it was Karl *, Schwarzchild who iui 1895 [ Schwarzschild (190)] made the first measure- ments of binary stars...J. Lett 163. Michelson, A A, Pease. F. G. 1921. Ap. 280: L23 J. 53: 249 190. Schwarzschild . K. 1896. Astron. Nadir. 164. Morgan. B. L., lieddoes. 1

Optical design of a Michelson wide-field multiple-aperture telescope

Science.gov (United States)

Cassaing, Frederic; Sorrente, Beatrice; Fleury, Bruno; Laubier, David

2004-02-01

Multiple-Aperture Optical Telescopes (MAOTs) are a promising solution for very high resolution imaging. In the Michelson configuration, the instrument is made of sub-telescopes distributed in the pupil and combined by a common telescope via folding periscopes. The phasing conditions of the sub-pupils lead to specific optical constraints in these subsystems. The amplitude of main contributors to the wavefront error (WFE) is given as a function of high level requirements (such as field or resolution) and free parameters, mainly the sub-telescope type, magnification and diameter. It is shown that for the periscopes, the field-to-resolution ratio is the main design driver and can lead to severe specifications. The effect of sub-telescopes aberrations on the global WFE can be minimized by reducing their diameter. An analytical tool for the MAOT design has been derived from this analysis, illustrated and validated in three different cases: LEO or GEO Earth observation and astronomy with extremely large telescopes. The last two cases show that a field larger than 10 000 resolution elements can be covered with a very simple MAOT based on Mersenne paraboloid-paraboloid sub-telescopes. Michelson MAOTs are thus a solution to be considered for high resolution wide-field imaging, from space or ground.

Tunneling anisotropic magnetoresistance in C60-based organic spintronic systems

NARCIS (Netherlands)

Wang, Kai; Sanderink, Johannes G.M.; Bolhuis, Thijs; van der Wiel, Wilfred Gerard; de Jong, Machiel Pieter

2014-01-01

C 60 fullerenes are interesting molecular semiconductors for spintronics since they exhibit weak spin-orbit and hyperfine interactions, which is a prerequisite for long spin lifetimes. We report spin-polarized transport in spin-valve-like structures containing ultrathin (<10 nm) C 60 layers,

Magnetic polyoxometalates: from molecular magnetism to molecular spintronics and quantum computing.

Science.gov (United States)

Clemente-Juan, Juan M; Coronado, Eugenio; Gaita-Ariño, Alejandro

2012-11-21

In this review we discuss the relevance of polyoxometalate (POM) chemistry to provide model objects in molecular magnetism. We present several potential applications in nanomagnetism, in particular, in molecular spintronics and quantum computing.

Distributed acoustic sensing with Michelson interferometer demodulation

Science.gov (United States)

Liu, Xiaohui; Wang, Chen; Shang, Ying; Wang, Chang; Zhao, Wenan; Peng, Gangding; Wang, Hongzhong

2017-09-01

The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

Introduction to spintronics

CERN Document Server

Bandyopadhyay, Supriyo

2008-01-01

The Early History of Spin Spin The Bohr Planetary Model and Space Quantization The Birth of "Spin" The Stern-Gerlach Experiment The Advent of Spintronics The Quantum Mechanics of Spin Pauli Spin Matrices The Pauli Equation and Spinors More on the Pauli Equation Extending the Pauli Equation - the Dirac Equation The Time Independent Dirac Equation Appendix The Bloch Sphere The Spinor and the "Qubit" The Bloch Sphere Concept Evolution of a Spinor Spin-1/2 Particle in a Constant Magnetic Field: Larmor Precession Preparing to Derive the Rabi Formula The Rabi Formula The Density Matrix The Density Matrix Concept: Case of a Pure State Properties of the Density Matrix Pure Versus Mixed State Concept of the Bloch Ball Time Evolution of the Density Matrix: Case of Mixed State The Relaxation Times T1 and T2 and the Bloch Equations Spin Orbit Interaction Spin Orbit Interaction in a Solid Magneto-Electric Sub-Bands in Quantum Confined Structures in the Presence of Spin-Orbit Interaction Dispersion Relations of Spin Resolv...

Surface spintronics enhanced photo-catalytic hydrogen evolution: Mechanisms, strategies, challenges and future

Science.gov (United States)

Zhang, Wenyan; Gao, Wei; Zhang, Xuqiang; Li, Zhen; Lu, Gongxuan

2018-03-01

Hydrogen is a green energy carrier with high enthalpy and zero environmental pollution emission characteristics. Photocatalytic hydrogen evolution (HER) is a sustainable and promising way to generate hydrogen. Despite of great achievements in photocatalytic HER research, its efficiency is still limited due to undesirable electron transfer loss, high HER over-potential and low stability of some photocatalysts, which lead to their unsatisfied performance in HER and anti-photocorrosion properties. In recent years, many spintronics works have shown their enhancing effects on photo-catalytic HER. For example, it was reported that spin polarized photo-electrons could result in higher photocurrents and HER turn-over frequency (up to 200%) in photocatalytic system. Two strategies have been developed for electron spin polarizing, which resort to heavy atom effect and magnetic induction respectively. Both theoretical and experimental studies show that controlling spin state of OHrad radicals in photocatalytic reaction can not only decrease OER over-potential (even to 0 eV) of water splitting, but improve stability and charge lifetime of photocatalysts. A convenient strategy have been developed for aligning spin state of OHrad by utilizing chiral molecules to spin filter photo-electrons. By chiral-induced spin filtering, electron polarization can approach to 74%, which is significantly larger than some traditional transition metal devices. Those achievements demonstrate bright future of spintronics in enhancing photocatalytic HER, nevertheless, there is little work systematically reviewing and analysis this topic. This review focuses on recent achievements of spintronics in photocatalytic HER study, and systematically summarizes the related mechanisms and important strategies proposed. Besides, the challenges and developing trends of spintronics enhanced photo-catalytic HER research are discussed, expecting to comprehend and explore such interdisciplinary research in

Near-infrared spectral imaging Michelson interferometer for astronomical applications

Science.gov (United States)

Wells, C. W.; Potter, A. E.; Morgan, T. H.

1980-01-01

The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

Increasing LIGO sensitivity by feedforward subtraction of auxiliary length control noise

International Nuclear Information System (INIS)

Meadors, Grant David; Riles, Keith; Kawabe, Keita

2014-01-01

LIGO, the Laser Interferometer Gravitational-wave Observatory, has been designed and constructed to measure gravitational wave strain via differential arm length. The LIGO 4 km Michelson arms with Fabry–Perot cavities have auxiliary length control servos for suppressing Michelson motion of the beam-splitter and arm cavity input mirrors, which degrades interferometer sensitivity. We demonstrate how a post facto pipeline improves a data sample from LIGO Science Run 6 with feedforward subtraction. Dividing data into 1024 s windows, we numerically fit filter functions representing the frequency-domain transfer functions from Michelson length channels into the gravitational-wave strain data channel for each window, then subtract the filtered Michelson channel noise (witness) from the strain channel (target). In this paper we describe the algorithm, assess achievable improvements in sensitivity to astrophysical sources, and consider relevance to future interferometry. (paper)

Quantum noise of a Michelson-Sagnac interferometer with a translucent mechanical oscillator

International Nuclear Information System (INIS)

Yamamoto, Kazuhiro; Friedrich, Daniel; Westphal, Tobias; Gossler, Stefan; Danzmann, Karsten; Schnabel, Roman; Somiya, Kentaro; Danilishin, Stefan L.

2010-01-01

Quantum fluctuations in the radiation pressure of light can excite stochastic motions of mechanical oscillators thereby realizing a linear quantum opto-mechanical coupling. When performing a precise measurement of the position of an oscillator, this coupling results in quantum radiation pressure noise. Up to now this effect has not been observed yet. Generally speaking, the strength of radiation pressure noise increases when the effective mass of the oscillator is decreased or when the power of the reflected light is increased. Recently, extremely light SiN membranes (≅100 ng) with high mechanical Q values at room temperature (≥10 6 ) have attracted attention as low thermal noise mechanical oscillators. However, the power reflectance of these membranes is much lower than unity (<0.4 at a wavelength of 1064 nm) which makes the use of advanced interferometer recycling techniques to amplify the radiation pressure noise in a standard Michelson interferometer inefficient. Here, we propose and theoretically analyze a Michelson-Sagnac interferometer that includes the membrane as a common end mirror for the Michelson interferometer part. In this topology, both power and signal recycling can be used even if the reflectance of the membrane is much lower than unity. In particular, signal recycling is a useful tool because it does not involve a power increase at the membrane. We derive the formulas for the quantum radiation pressure noise and the shot noise of an oscillator position measurement and compare them with theoretical models of the thermal noise of a SiN membrane with a fundamental resonant frequency of 75 kHz and an effective mass of125 ng. We find that quantum radiation pressure noise should be observable with a power of 1 W at the central beam splitter of the interferometer and a membrane temperature of 1 K.

Broadband sensitivity enhancement of detuned dual-recycled Michelson interferometers with EPR entanglement

Science.gov (United States)

Brown, Daniel D.; Miao, Haixing; Collins, Chris; Mow-Lowry, Conor; Töyrä, Daniel; Freise, Andreas

2017-09-01

We demonstrate the applicability of the EPR entanglement squeezing scheme for enhancing the shot-noise-limited sensitivity of detuned dual-recycled Michelson interferometers. In particular, this scheme is applied to the GEO600 interferometer. The effect of losses throughout the interferometer, arm length asymmetries, and imperfect separation of the signal and idler beams is considered.

Study of optically thin electron cyclotron emission from TFTR using a Michelson interferometer

International Nuclear Information System (INIS)

Stauffer, F.J.; Boyd, D.A.

1986-01-01

The TFTR Michelson interferometer, which is used as an electron temperature diagnostic, has a spectral range of 75-540 GHz. This range is adequate for measuring at least the first three cyclotron harmonics, and it spans both optically thick and thin portions of the ECE spectrum. During the most recent opening of the TFTR vacuum vessel, a concave, carbon reflector was installed on the back wall of the vessel, opposite the light collecting optic of the Michelson system. The reflector is designed to prevent the observation of optically thin ECE that originates from a location that is outside the field of view of the light collecting optic. If this is achieved, it should be possible to derive the electron density profile from measurements of either the extraordinary mode third harmonic or the ordinary mode second harmonic. An analysis of ECE spectra that have been measured before and after installation of the reflector is presented

Development of Michelson interferometer based spatial phase-shift digital shearography

Science.gov (United States)

Xie, Xin

Digital shearography is a non-contact, full field, optical measurement method, which has the capability of directly measuring the gradient of deformation. For high measurement sensitivity, phase evaluation method has to be introduced into digital shearography by phase-shift technique. Catalog by phase-shift method, digital phase-shift shearography can be divided into Temporal Phase-Shift Digital Shearography (TPS-DS) and Spatial Phase-Shift Digital Shearography (SPS-DS). TPS-DS is the most widely used phase-shift shearography system, due to its simple algorithm, easy operation and good phase-map quality. However, the application of TPS-DS is only limited in static/step-by-step loading measurement situation, due to its multi-step shifting process. In order to measure the strain under dynamic/continuous loading situation, a SPS-DS system has to be developed. This dissertation aims to develop a series of Michelson Interferometer based SPS-DS measurement methods to achieve the strain measurement by using only a single pair of speckle pattern images. The Michelson Interferometer based SPS-DS systems utilize special designed optical setup to introduce extra carrier frequency into the laser wavefront. The phase information corresponds to the strain field can be separated on the Fourier domain using a Fourier Transform and can further be evaluated with a Windowed Inverse Fourier Transform. With different optical setups and carrier frequency arrangements, the Michelson Interferometer based SPS-DS method is capable to achieve a variety of measurement tasks using only single pair of speckle pattern images. Catalog by the aimed measurand, these capable measurement tasks can be divided into five categories: 1) measurement of out-of-plane strain field with small shearing amount; 2) measurement of relative out-of-plane deformation field with big shearing amount; 3) simultaneous measurement of relative out-of-plane deformation field and deformation gradient field by using multiple

Magnetization Dynamics in Two Novel Current-Driven Spintronic Memory Cell Structures

KAUST Repository

Velazquez-Rizo, Martin

2017-01-01

In this work, two new spintronic memory cell structures are proposed. The first cell uses the diffusion of polarized spins into ferromagnets with perpendicular anisotropy to tilt their magnetization followed by their dipolar coupling to a fixed

Dynamic spectro-polarimeter based on a modified Michelson interferometric scheme.

Science.gov (United States)

Dembele, Vamara; Jin, Moonseob; Baek, Byung-Joon; Kim, Daesuk

2016-06-27

A simple dynamic spectro-polarimeter based on a modified Michelson interferometric scheme is described. The proposed system can extract a spectral Stokes vector of a transmissive anisotropic object. Detail theoretical background is derived and experiments are conducted to verify the feasibility of the proposed novel snapshot spectro-polarimeter. The proposed dynamic spectro-polarimeter enables us to extract highly accurate spectral Stokes vector of any transmissive anisotropic object with a frame rate of more than 20Hz.

Superposition of helical beams by using a Michelson interferometer.

Science.gov (United States)

Gao, Chunqing; Qi, Xiaoqing; Liu, Yidong; Weber, Horst

2010-01-04

Orbital angular momentum (OAM) of a helical beam is of great interests in the high density optical communication due to its infinite number of eigen-states. In this paper, an experimental setup is realized to the information encoding and decoding on the OAM eigen-states. A hologram designed by the iterative method is used to generate the helical beams, and a Michelson interferometer with two Porro prisms is used for the superposition of two helical beams. The experimental results of the collinear superposition of helical beams and their OAM eigen-states detection are presented.

Optical path difference measurements with a two-step parallel phase shifting interferometer based on a modified Michelson configuration

Science.gov (United States)

Toto-Arellano, Noel Ivan; Serrano-Garcia, David I.; Rodriguez-Zurita, Gustavo

2017-09-01

We report an optical implementation of a parallel phase-shifting quasi-common path interferometer using two modified Michelson interferometers to generate two interferograms. By using a displaceable polarizer's array, placed on the image plane, we can obtain four phase-shifted interferograms in two captures. The system operates as a quasi-common path interferometer generating four beams, which are to interfere with alignment procedures on the mirrors of the Michelson configurations. The optical phase data are retrieved using the well-known four-step algorithms. To present the capabilities of the system, experimental results obtained from transparent structures are presented.

Modulation depth of Michelson interferometer with Gaussian beam.

Science.gov (United States)

Välikylä, Tuomas; Kauppinen, Jyrki

2011-12-20

Mirror misalignment or the tilt angle of the Michelson interferometer can be estimated from the modulation depth measured with collimated monochromatic light. The intensity of the light beam is usually assumed to be uniform, but, for example, with gas lasers it generally has a Gaussian distribution, which makes the modulation depth less sensitive to the tilt angle. With this assumption, the tilt angle may be underestimated by about 50%. We have derived a mathematical model for modulation depth with a circular aperture and Gaussian beam. The model reduces the error of the tilt angle estimate to below 1%. The results of the model have been verified experimentally.

Ferromagnetism in doped or undoped spintronics nanomaterials

Science.gov (United States)

Qiang, You

2010-10-01

Much interest has been sparked by the discovery of ferromagnetism in a range of oxide doped and undoped semiconductors. The development of ferromagnetic oxide semiconductor materials with giant magnetoresistance (GMR) offers many advantages in spintronics devices for future miniaturization of computers. Among them, TM-doped ZnO is an extensively studied n-type wide-band-gap (3.36 eV) semiconductor with a tremendous interest as future mini-computer, blue light emitting, and solar cells. In this talk, Co-doped ZnO and Co-doped Cu2O semiconductor nanoclusters are successfully synthesized by a third generation sputtering-gas-aggregation cluster technique. The Co-doped nanoclusters are ferromagnetic with Curie temperature above room temperature. Both of Co-doped nanoclusters show positive magnetoresistance (PMR) at low temperature, but the amplitude of the PMRs shows an anomalous difference. For similar Co doping concentration at 5 K, PMR is greater than 800% for Co-doped ZnO but only 5% for Co-doped Cu2O nanoclusters. Giant PMR in Co-doped ZnO which is attributed to large Zeeman splitting effect has a linear dependence on applied magnetic field with very high sensitivity, which makes it convenient for the future spintronics applications. The small PMR in Co-doped Cu2O is related to its vanishing density of states at Fermi level. Undoped Zn/ZnO core-shell nanoparticle gives high ferromagnetic properties above room temperature due to the defect induced magnetization at the interface.

Hybrid Spintronic-CMOS Spiking Neural Network with On-Chip Learning: Devices, Circuits, and Systems

Science.gov (United States)

Sengupta, Abhronil; Banerjee, Aparajita; Roy, Kaushik

2016-12-01

Over the past decade, spiking neural networks (SNNs) have emerged as one of the popular architectures to emulate the brain. In SNNs, information is temporally encoded and communication between neurons is accomplished by means of spikes. In such networks, spike-timing-dependent plasticity mechanisms require the online programing of synapses based on the temporal information of spikes transmitted by spiking neurons. In this work, we propose a spintronic synapse with decoupled spike-transmission and programing-current paths. The spintronic synapse consists of a ferromagnet-heavy-metal heterostructure where the programing current through the heavy metal generates spin-orbit torque to modulate the device conductance. Low programing energy and fast programing times demonstrate the efficacy of the proposed device as a nanoelectronic synapse. We perform a simulation study based on an experimentally benchmarked device-simulation framework to demonstrate the interfacing of such spintronic synapses with CMOS neurons and learning circuits operating in the transistor subthreshold region to form a network of spiking neurons that can be utilized for pattern-recognition problems.

Spintronic materials and devices based on antiferromagnetic metals

OpenAIRE

Wang, Y.Y.; Song, C.; Zhang, J.Y.; Pan, F.

2017-01-01

In this paper, we review our recent experimental developments on antiferromagnet (AFM) spintronics mainly comprising Mn-based noncollinear AFM metals. IrMn-based tunnel junctions and Hall devices have been investigated to explore the manipulation of AFM moments by magnetic fields, ferromagnetic materials and electric fields. Room-temperature tunneling anisotropic magnetoresistance based on IrMn as well as FeMn has been successfully achieved, and electrical control of the AFM exchange spring i...

Infrared Interferometry of Auroral Ionosphere-Thermosphere Energetics Project

Data.gov (United States)

National Aeronautics and Space Administration —  The FWMI prototype development is underway at USU/SDL. To develop the FWMI, USU/SDL is leveraging the successful implementation of a rocket-borne Michelson...

Direct UV written Michelson interferometer for RZ signal generation using phase-to-intensity modulation conversion

DEFF Research Database (Denmark)

Peucheret, Christophe; Geng, Yan; Zsigri, Beata

2005-01-01

An integrated Michelson delay interferometer structure making use of waveguide gratings as reflective elements is proposed and fabricated by direct ultraviolet writing. Successful return-to-zero alternate-mark-inversion signal generation using phase-to-intensity modulation conversion...

Quantum Mechanical Noise in a Michelson Interferometer with Nonclassical Inputs: Nonperturbative Treatment

Science.gov (United States)

King, Sun-Kun

1996-01-01

The variances of the quantum-mechanical noise in a two-input-port Michelson interferometer within the framework of the Loudon-Ni model were solved exactly in two general cases: (1) one coherent state input and one squeezed state input, and (2) two photon number states inputs. Low intensity limit, exponential decaying signal and the noise due to mixing were discussed briefly.

Early Type Stars as Calibrators for Ground-Based Interferometry

National Research Council Canada - National Science Library

Yoon, Jinmi; Peterson, Deane M; Amstrong, Thomas; Clark III, James H; Gilbreath, Charmaine; Pauls, Thomas; Schmitt, Henrique R

2006-01-01

Visibility measurements with Michelson interferometers, particularly the measurement of fringe contrast, are affected by various atmospheric and instrumental effects, all of which reduce the measured contrast...

Spintronic and transport properties of linear atomic strings of transition metals (Fe, Co, Ni)

Energy Technology Data Exchange (ETDEWEB)

Tyagi, Neha, E-mail: nehatyagi.phy@gmail.com [Department of Applied Physics, Delhi Technological University, New Delhi (India); Jaiswal, Neeraj K. [Discipline of Physics, PDPM-Indian Institute of Information Technology, Design & Manufacturing, Jabalpur (India); Srivastava, Pankaj [Nanomaterials Research Group, ABV-Indian Institute of Information Technology & Management, Gwalior (India)

2016-05-06

In the present work, first-principles investigations have been performed to study the spintronic and transport properties of linear atomic strings of Fe, Co and Ni. The structural stabilities of the considered strings were compared on the basis of binding energies which revealed that all the strings are energetically feasible to be achieved. Further, all the considered strings are found to be ferromagnetic and the observed magnetic moment ranges from 1.38 to 1.71 μ{sub B}. The observed transport properties and high spin polarization points towards their potential for nano interconnects and spintronic applications.

Antihydrogen Experiment Gravity Interferometry Spectroscopy

CERN Multimedia

Trezzi, D; Dassa, L; Rienacker, B; Khalidova, O; Ferrari, G; Krasnicky, D; Perini, D; Cerchiari, G; Belov, A; Boscolo, I; Sacerdoti, M G; Ferragut, R O; Nedelec, P; Hinterberger, A; Al-qaradawi, I; Malbrunot, C L S; Brusa, R S; Prelz, F; Manuzio, G; Riccardi, C; Fontana, A; Genova, P; Haider, S; Haug, F; Turbabin, A; Castelli, F; Testera, G; Lagomarsino, V E; Doser, M; Penasa, L; Gninenko, S; Cataneo, F; Zenoni, A; Cabaret, L; Comparat, D P; Zmeskal, J; Scampoli, P; Nesteruk, K P; Dudarev, A; Kellerbauer, A G; Mariazzi, S; Carraro, C; Zavatarelli, S M

The AEGIS experiment (Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy) has the aim of carrying out the first measurement of the gravitational interaction of antimatter to a precision of 1%, by applying techniques from atomic physics, laser spectroscopy and interferometry to a beam of antihydrogen atoms. A further goal of the experiment is to carry out spectroscopy of the antihydrogen atoms in flight.

Atomic interferometry

International Nuclear Information System (INIS)

Baudon, J.; Robert, J.

2004-01-01

Since the theoretical works of L. De Broglie (1924) and the famous experiment of Davisson and Germer (1927), we know that a wave is linked with any particle of mass m by the relation λ = h/(mv), where λ is the wavelength, v the particle velocity and h is the Planck constant. The basic principle of the interferometry of any material particle, atom, molecule or aggregate is simple: using a simple incident wave, several mutually consistent waves (with well-defined relative phases) are generated and controllable phase-shifts are introduced between them in order to generate a wave which is the sum of the previous waves. An interference figure is obtained which consists in a succession of dark and bright fringes. The atomic interferometry is based on the same principle but involves different techniques, different wave equations, but also different beams, sources and correlations which are described in this book. Because of the small possible wavelengths and the wide range of possible atomic interactions, atomic interferometers can be used in many domains from the sub-micron lithography to the construction of sensors like: inertial sensors, gravity-meters, accelerometers, gyro-meters etc. The first chapter is a preliminary study of the space and time diffraction of atoms. The next chapters is devoted to the description of slit, light separation and polarization interferometers, and the last chapter treats of the properties of Bose-Einstein condensates which are interesting in atomic interferometry. (J.S.)

Dissipative optomechanics in a Michelson-Sagnac interferometer.

Science.gov (United States)

Xuereb, André; Schnabel, Roman; Hammerer, Klemens

2011-11-18

Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson-Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-the-art parameters, ground-state cooling and low-power quantum-limited position transduction are both possible. The possibility of a strong, tunable dissipative coupling opens up a new route towards observation of such fundamental optomechanical effects as nonlinear dynamics. Beyond optomechanics, the suggested method can be readily transferred to other setups involving nonlinear media, atomic ensembles, or single atoms.

Transverse coherence measurement using a folded Michelson interferometer.

Science.gov (United States)

Dean, Jesse; Bercx, Martin; Nantel, Marc; Marjoribanks, Robin

2007-06-01

The transverse coherence of a 1 ps pulsed laser beam was measured using a technique involving a modified Michelson interferometer and separate reference images. Using this technique, the transverse coherence of a selected plane in the laser beam was determined, in this case at the exit of a channel in a metal foil self-drilled by the laser. Images of each arm were used as references. Through this technique, it is possible to use the interference patterns produced with uneven intensity distributions and for pulsed lasers on a single-shot basis. The results of these measurements were then shown to be in agreement with those obtained using a Young's double-slit setup.

Prediction of novel interface-driven spintronic effects

International Nuclear Information System (INIS)

Bhattacharjee, Satadeep; Singh, Surendra; Bellaiche, L; Wang, D; Viret, M

2014-01-01

The recently proposed coupling between the angular momentum density and magnetic moment (Raeliarijaona et al 2013 Phys. Rev. Lett. 110 137205) is shown here to result in the prediction of (i) novel spin currents generated by an electrical current and (ii) new electrical currents induced by a spin current in systems possessing specific interfaces between two different materials. Some of these spin (electrical) currents can be reversed near the interface by reversing the applied electrical (spin) current. Similarities and differences between these novel spintronic effects and the well-known spin Hall and inverse spin Hall effects are also discussed. (paper)

Measurement of periodically varying ECE spectra using a Michelson interferometer

International Nuclear Information System (INIS)

Laurent, L.; Rodriguez, L.; Talvard, M.

1987-01-01

In some tokamak experiments the ECE spectrum is periodically varying. If the modulation frequency is small enough (less than 10 Hz) the plasma can be considered as quasi-stationary during the typical scan time of most of the Michelson interferometers. It is possible to measure simply ECE spectra at different times of the oscillation. We present here a technique which allows to measure smaller fluctuations at larger frequencies. However the analysis requires a large number of periods of oscillation at constant frequency and a scanning mirror moving at constant velocity

Analysis of a sub-shot-noise power recycled Michelson interferometer

International Nuclear Information System (INIS)

McKenzie, K; Buchler, B C; Shaddock, D A; Lam, P K; McClelland, D E

2004-01-01

The sensitivity of interferometric gravitational wave detectors is ultimately limited by the 'quantum noise' of light. In this paper we compare results from a bench-top experiment and a theoretical model which show how squeezed states of light may be used to modify the quantum noise behaviour of a power recycled Michelson interferometer. We develop a simple theoretical model of the experiment and find close agreement of theoretical and experimental results. We measure quantum noise suppression of 2.3 dB and demonstrate the lock stability of the experiment for long periods

Correlated two-photon interference in a dual-beam Michelson interferometer

International Nuclear Information System (INIS)

Kwiat, P.G.; Vareka, W.A.; Hong, C.K.; Nathel, H.; Chiao, R.Y.

1990-01-01

We report on an interference effect arising from a two-photon entangled state produced in a potassium dihydrogen phosphate (KDP) crystal pumped by an ultraviolet argon-ion laser. Two conjugate beams of signal and idler photons were injected in a parallel configuration into a single Michelson interferometer, and detected separately by two photomultipliers, while the difference in its arm lengths was slowly scanned. The coincidence rate exhibited fringes with a visibility of nearly 50%, and a period given by half the ultraviolet (not the signal or idler) wavelength, while the singles rate exhibited no fringes

Recent Advance in Organic Spintronics and Magnetic Field Effect

Science.gov (United States)

Valy Vardeny, Z.

2013-03-01

In this talk several important advances in the field of Organic Spintronics and magnetic field effect (MFE) of organic films and optoelectronic devices that have occurred during the past two years from the Utah group will be surveyed and discussed. (i) Organic Spintronics: We demonstrated spin organic light emitting diode (spin-OLED) using two FM injecting electrodes, where the electroluminescence depends on the mutual orientation of the electrode magnetization directions. This development has opened up research studies into organic spin-valves (OSV) in the space-charge limited current regime. (ii) Magnetic field effect: We demonstrated that the photoinduced absorption spectrum in organic films (where current is not involved) show pronounced MFE. This unravels the underlying mechanism of the MFE in organic devices, to be more in agreement with the field of MFE in Biochemistry. (iii) Spin effects in organic optoelectronic devices: We demonstrated that certain spin 1/2 radical additives to donor-acceptor blends substantially enhance the power conversion efficiency of organic photovoltaic (OPV) solar cells. This effect shows that studies of spin response and MFE in OPV devices are promising. In collaboration with T. Nguyen, E. Ehrenfreund, B. Gautam, Y. Zhang and T. Basel. Supported by the DOE grant 04ER46109 ; NSF Grant # DMR-1104495 and MSF-MRSEC program DMR-1121252 [2,3].

Giant magnetoresistance in lateral metallic nanostructures for spintronic applications.

Science.gov (United States)

Zahnd, G; Vila, L; Pham, V T; Marty, A; Beigné, C; Vergnaud, C; Attané, J P

2017-08-25

In this letter, we discuss the shift observed in spintronics from the current-perpendicular-to-plane geometry towards lateral geometries, illustrating the new opportunities offered by this configuration. Using CoFe-based all-metallic LSVs, we show that giant magnetoresistance variations of more than 10% can be obtained, competitive with the current-perpendicular-to-plane giant magnetoresistance. We then focus on the interest of being able to tailor freely the geometries. On the one hand, by tailoring the non-magnetic parts, we show that it is possible to enhance the spin signal of giant magnetoresistance structures. On the other hand, we show that tailoring the geometry of lateral structures allows creating a multilevel memory with high spin signals, by controlling the coercivity and shape anisotropy of the magnetic parts. Furthermore, we study a new device in which the magnetization direction of a nanodisk can be detected. We thus show that the ability to control the magnetic properties can be used to take advantage of all the spin degrees of freedom, which are usually occulted in current-perpendicular-to-plane devices. This flexibility of lateral structures relatively to current-perpendicular-to-plane structures is thus found to offer a new playground for the development of spintronic applications.

Compact magnetic-field sensor based on optical microfiber Michelson interferometer and Fe3O4 nanofluid.

Science.gov (United States)

Deng, Ming; Sun, Xiaokang; Han, Meng; Li, Decai

2013-02-01

We report a magnetic-field sensor by merging the advantages of optical fiber Michelson interferometers with that of magnetic fluid. Compact and low-cost optical fiber Michelson interferometers were first fabricated by a high-frequency CO(2) laser, and then they were inserted into glass capillaries with water-based Fe(3)O(4) magnetic fluid as sensing elements. The sensing characteristics have been investigated and the experimental results show that the reflective spectrum of the fiber-magnetic sensor linearly shifted with the change of the magnetic-field strength that is perpendicular to the axial of the devices. The fiber-magnetic sensor with interference arm's diameter of 50 μm is most sensitive to the external magnetic field, and the sensitivity is up to 64.9 pm/mT, which is 20 times higher than that of 125 μm diameter.

Analysis of surface absorbed dose in X-ray grating interferometry

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhili, E-mail: wangnsrl@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Wu, Zhao; Gao, Kun; Wang, Dajiang; Chen, Heng; Wang, Shenghao [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Wu, Ziyu, E-mail: wuzy@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2014-10-15

Highlights: • Theoretical framework for dose estimation in X-ray grating interferometry. • Potential dose reduction of X-ray grating interferometry compared to conventional radiography. • Guidelines for optimization of X-ray grating interferometry for dose-sensitive applications. • Measure to compare various existing X-ray phase contrast imaging techniques. - Abstract: X-ray phase contrast imaging using grating interferometry has shown increased contrast over conventional absorption imaging, and therefore the great potential of dose reduction. The extent of the dose reduction depends on the geometry of grating interferometry, the photon energy, the properties of the sample under investigation and the utilized detector. These factors also determine the capability of grating interferometry to distinguish between different tissues with a specified statistical certainty in a single raw image. In this contribution, the required photon number for imaging and the resulting surface absorbed dose are determined in X-ray grating interferometry, using a two-component imaging object model. The presented results confirm that compared to conventional radiography, phase contrast imaging using grating interferometry indeed has the potential of dose reduction. And the extent of dose reduction is strongly dependent on the imaging conditions. Those results provide a theoretical framework for dose estimation under given imaging conditions before experimental trials, and general guidelines for optimization of grating interferometry for those dose-sensitive applications.

Analysis of surface absorbed dose in X-ray grating interferometry

International Nuclear Information System (INIS)

Wang, Zhili; Wu, Zhao; Gao, Kun; Wang, Dajiang; Chen, Heng; Wang, Shenghao; Wu, Ziyu

2014-01-01

Highlights: • Theoretical framework for dose estimation in X-ray grating interferometry. • Potential dose reduction of X-ray grating interferometry compared to conventional radiography. • Guidelines for optimization of X-ray grating interferometry for dose-sensitive applications. • Measure to compare various existing X-ray phase contrast imaging techniques. - Abstract: X-ray phase contrast imaging using grating interferometry has shown increased contrast over conventional absorption imaging, and therefore the great potential of dose reduction. The extent of the dose reduction depends on the geometry of grating interferometry, the photon energy, the properties of the sample under investigation and the utilized detector. These factors also determine the capability of grating interferometry to distinguish between different tissues with a specified statistical certainty in a single raw image. In this contribution, the required photon number for imaging and the resulting surface absorbed dose are determined in X-ray grating interferometry, using a two-component imaging object model. The presented results confirm that compared to conventional radiography, phase contrast imaging using grating interferometry indeed has the potential of dose reduction. And the extent of dose reduction is strongly dependent on the imaging conditions. Those results provide a theoretical framework for dose estimation under given imaging conditions before experimental trials, and general guidelines for optimization of grating interferometry for those dose-sensitive applications

O2 atmospheric band measurements with WINDII: Performance of a narrow band filter/wide angle Michelson combination in space

International Nuclear Information System (INIS)

Ward, W.E.; Hersom, C.H.; Tai, C.C.; Gault, W.A.; Shepherd, G.G.; Solheim, B.H.

1994-01-01

Among the emissions viewed by the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS) are selected lines in the (0-0) transition of the O2 atmospheric band. These lines are viewed simultaneously using a narrow band filter/wide-angle Michelson interferometer combination. The narrow band filter is used to separate the lines on the CCD (spectral-spatial scanning) and the Michelson used to modulate the emissions so that winds and rotational temperatures may be measured from the Doppler shifts and relative intensities of the lines. In this report this technique will be outlined and the on-orbit behavior since launch summarized

Phase-shift interferometry with a digital photocamera

International Nuclear Information System (INIS)

Vannoni, Maurizio; Trivi, Marcelo; Molesini, Giuseppe

2007-01-01

A phase-shift interferometry experiment is proposed, working on a Twyman-Green optical configuration with additional polarization components. A guideline is provided to modern phase-shift interferometry, using concepts and laboratory equipment at the level of undergraduate optics courses

A system for airborne SAR interferometry

DEFF Research Database (Denmark)

Madsen, Søren Nørvang; Skou, Niels; Granholm, Johan

1996-01-01

Interferometric synthetic aperture radar (INSAR) systems have already demonstrated that elevation maps can be generated rapidly with single pass airborne across-track interferometry systems (XTT), and satellite repeat track interferometry (RTT) techniques have been used to map both elevation...... and perturbations of the surface of the Earth. The Danish Center for Remote Sensing (DCRS) has experimented with airborne INSAR since 1993. Multiple track data are collected in a special mode in which the radar directly steers the aircraft which allows for very precise control of the flight path. Such data sets......) the status of the airborne interferometry activities at DCRS, including the present system configuration, recent results, and some scientific applications of the system....

Superconducting spin switch based on superconductor-ferromagnet nanostructures for spintronics

International Nuclear Information System (INIS)

Kehrle, Jan; Mueller, Claus; Obermeier, Guenter; Schreck, Matthias; Gsell, Stefan; Horn, Siegfried; Tidecks, Reinhard; Zdravkov, Vladimir; Morari, Roman; Sidorencko, Anatoli; Prepelitsa, Andrei; Antropov, Evgenii; Socrovisciiuc, Alexei; Nold, Eberhard; Tagirov, Lenar

2011-01-01

Very rapid developing area, spintronics, needs new devices, based on new physical principles. One of such devices - a superconducting spin-switch, consists of ferromagnetic and superconducting layers, and is based on a new phenomenon - reentrant superconductivity. The tuning of the superconducting and ferromagnetic layers thickness is investigated to optimize superconducting spin-switch effect for Nb/Cu 41 Ni 59 based nanoscale layered systems.

Einstein, the exponential metric, and a proposed gravitational Michelson-Morley experiment

International Nuclear Information System (INIS)

Yilmaz, H.

1979-01-01

An early but potentially important remark of Einstein on the exponential nature of time-dilation is discussed. Using the same argument for the length-contraction, plus two alternative kinematical assumptions, the Schwarzschild and exponential metrics are derived. A gravitational Michelson-Morley experiment with one arm directed along the vertical is proposed to test the metrics. The experiment may be considered as a laboratory test of the Schwarzschild field and possibly a test of the black-hole interpretation of collapsed matter

Design of a birefringent Michelson interferometer-based interleaver with ultra-low dispersion and low cost.

Science.gov (United States)

Hu, Haocheng; Zheng, Baozhong; Liu, Qingming; Li, Yang; Wu, Li; Gu, Shijie

2011-11-21

We design and demonstrate a birefringent Michelson interferometer based interleaver with ultra-low dispersion and low cost. The interleaver consists of polarizing beam splitters (PBS's) and quarter-wave plates and half-wave plates. The PBS's based Michelson interferometers provide the optical path difference for interference between the two orthogonal polarization components and the half-wave plates provide the birefringent needed to minimize ripple of output. The designed interleaver with two-stage interferometer in a 50 GHz channel spacing application exhibits a 0.5 dB passband and a 25 dB stopband both 27 GHz; a channel isolation higher than 35 dB and chromatic dispersion less than ±5 ps/nm within 0.5 dB passband; 1.3 dB insertion loss and 0.3 dB PDL; 0.04 GHz/°C thermal stability. Since all of the optical components can be optically bonded together, the device is robust and easy to be aligned, which reduces labor cost. © 2011 Optical Society of America

Kaon interferometry; Interferometria de kaons

Energy Technology Data Exchange (ETDEWEB)

Roldao, C.G.; Padula, S.S. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil)

1994-06-01

Preliminary results of the {chi}{sup 2} analysis where data on kaon interferometry, obtained from the E859 Collaboration of the AGS/Brookhaven Nat.Lab., are compared with results of a hadronic resonance production model are presented. The main goal is to test the resolution power of the method here discussed when applied to the two-dimensional kaon interferometry. 11 refs., 2 figs.; e-mail: roldao at axp.ift.unesp.br; padula at axp.ift.unesp.br.

Phase Referencing in Optical Interferometry

OpenAIRE

Filho, Mercedes E.; Garcia, Paulo; Duvert, Gilles; Duchene, Gaspard; Thiebaut, Eric; Young, John; Absil, Olivier; Berger, Jean-Phillipe; Beckert, Thomas; Hoenig, Sebastian; Schertl, Dieter; Weigelt, Gerd; Testi, Leonardo; Tatuli, Eric; Borkowski, Virginie

2008-01-01

One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two extremes of phase corruption by the atmosphere. While in radio it is possible to obtain calibrated phases for the science objects, in the optical this is currently not possible. Instead, optical interferometry has relied on closure phase techniques to produce...

Universal Michelson Gires-Tournois interferometer optical interleaver based on digital signal processing.

Science.gov (United States)

Zhang, Juan; Yang, Xiaowei

2010-03-01

Optical interleavers based on Michelson Gires-Tournois interferometer (MGTI) with arbitrary cascaded reflectors for symmetrical or asymmetrical periodic frequency response with arbitrary duty cycles are defined as universal MGTI optical interleaver (UMGTIOI). It can significantly enhance flexibility and applicability of optical networks. A novel and simple method based on digital signal processing is proposed for the design of UMGTIOI. Different kinds of design examples are given to confirm effectiveness of the method.

Effect of Earth's rotation on the quantum mechanical phase of the neutron

International Nuclear Information System (INIS)

Werner, S.A.; Staudenmann, J.; Colella, R.

1979-01-01

Using a neutron interferometer of the type first developed by Bonse and Hart for x rays, we have observed the effect of Earth's rotation on the phase of the neutron wave function. This experiment is the quantum mechanical analog of the optical interferometry observations of Michelson, Gale, and Pearson

Application of Young-Michelson and Brown-Twiss interferometers for determining geometric parameters of nonplanar rough objects

NARCIS (Netherlands)

Mandrosov, V. I.

The possibility of using Young-Michelson and Brown-Twiss interferometers for measuring the angular dimensions and parameters of the surface shape of remote passively scattering and self-luminous nonplanar rough objects by optical radiation propagating from them is substantiated. The analysis is

An ultrastable Michelson interferometer for high-resolution spectroscopy in the XUV.

Science.gov (United States)

Corsi, C; Liontos, I; Cavalieri, S; Bellini, M; Venturi, G; Eramo, R

2015-02-23

We developed an ultra-stable and accurately-controllable Michelson interferometer to be used in a deeply unbalanced arm configuration for split-pulse XUV Ramsey-type spectroscopy with high-order laser harmonics. The implemented active and passive stabilization systems allow one to reach instabilities in the nanometer range over meters of relative optical path differences. Producing precisely delayed pairs of pump pulses will generate XUV harmonic pulses that may significantly improve the achievable spectral resolution and the precision of absolute frequency measurements in the XUV.

Michelson interferometer with separated inputs and outputs, double pass, and compensation

Science.gov (United States)

Mather, J. C.; Jennings, D. E.

1985-01-01

A novel configuration is proposed for a Michelson interferometer spectrometer, which will be insensitive to tilts or displacements, and which employs separated inputs and outputs and double passing for higher resolution. The great advantage of such a compensated design is a relaxation of mechanical tolerances, which is especially beneficial for instruments in hostile environments. The Atmospheric Trace Molecule Spectroscopy project, which must work reliably after being subjected to the vibrations of a Space Shuttle launch, would benefit from the use of such an instrument.

Fast and low power Michelson interferometer thermo-optical switch on SOI.

Science.gov (United States)

Song, Junfeng; Fang, Q; Tao, S H; Liow, T Y; Yu, M B; Lo, G Q; Kwong, D L

2008-09-29

We designed and fabricated silicon-on-insulator based Michelson interferometer (MI) thermo-optical switches with deep etched trenches for heat-isolation. Switch power was reduced approximately 20% for the switch with deep etched trenches, and the MI saved approximately 50% power than that of the Mach-Zehnder interferometer. 10.6 mW switch power, approximately 42 micros switch time for the MI with deep trenches, 13.14 mW switch power and approximately 34 micros switch time for the MI without deep trenches were achieved.

Digital Double-Pulse Holographic Interferometry for Vibration Analysis

Directory of Open Access Journals (Sweden)

H.J. Tiziani

1996-01-01

Full Text Available Different arrangements for double-pulsed holographic and speckle interferometry for vibration analysis will be described. Experimental results obtained with films (classical holographic interferometry and CCD cameras (digital holographic interferometry as storage materials are presented. In digital holography, two separate holograms of an object under test are recorded within a few microseconds using a CCD camera and are stored in a frame grabber. The phases of the two reconstructed wave fields are calculated from the complex amplitudes. The deformation is obtained from the phase difference. In the case of electronic speckle pattern interferometry (or image plane hologram, the phase can be calculated by using the sinusoid-fitting method. In the case of digital holographic interferometry, the phase is obtained by digital reconstruction of the complex amplitudes of the wave fronts. Using three directions of illumination and one direction of observation, all the information necessary for the reconstruction of the 3-dimensional deformation vector can be recorded at the same time. Applications of the method for measuring rotating objects are discussed where a derotator needs to be used.

Evaluating Graphene as a Channel Material in Spintronic Logic Devices

Science.gov (United States)

Anugrah, Yoska

Spintronics, a class of devices that exploit the spin properties of electrons in addition to the charge properties, promises the possibility for nonvolatile logic and memory devices that operate at low power. Graphene is a material in which the spin orientation of electrons can be conserved over a long distance, which makes it an attractive channel material in spintronics devices. In this dissertation, the properties of graphene that are interesting for spintronics applications are explored. A robust fabrication process is described for graphene spin valves using Al2O3 tunnel tunnel barriers and Co ferromagnetic contacts. Spin transport was characterized in both few-layer exfoliated and single-layer graphene, and spin diffusion lengths and spin relaxation times were extracted using the nonlocal spin valve geometry and Hanle measurements. The effect of input-output asymmetry on the spin transport was investigated. The effect of an applied drift electric field on spin transport was investigated and the spin diffusion length was found to be tunable by a factor of 8X (suppressed to 1.6 microm and enhanced to 13 microm from the intrinsic length of 4.6 microm using electric field of +/-1800 V/cm). A mechanism to induce asymmetry without excess power dissipation is also described which utilizes a double buried-gate structure to tune the Fermi levels on the input and output sides of a graphene spin logic device independently. It was found that different spin scattering mechanisms were at play in the two halves of a small graphene strip. This suggests that the spin properties of graphene are strongly affected by its local environment, e.g. impurities, surface topography, defects. Finally, two-dimensional materials beyond graphene have been explored as spin channels. One such material is phosphorene, which has low spin-orbit coupling and high mobility, and the interface properties of ferromagnets (cobalt and permalloy) with this material were explored. This work could

A bit-rate flexible and power efficient all-optical demultiplexer realised by monolithically integrated Michelson interferometer

DEFF Research Database (Denmark)

Vaa, Michael; Mikkelsen, Benny; Jepsen, Kim Stokholm

1996-01-01

A novel bit-rate flexible and very power efficient all-optical demultiplexer using differential optical control of a monolithically integrated Michelson interferometer with MQW SOAs is demonstrated at 40 to 10 Gbit/s. Gain switched DFB lasers provide ultra stable data and control signals....

Phase estimation in optical interferometry

CERN Document Server

Rastogi, Pramod

2014-01-01

Phase Estimation in Optical Interferometry covers the essentials of phase-stepping algorithms used in interferometry and pseudointerferometric techniques. It presents the basic concepts and mathematics needed for understanding the phase estimation methods in use today. The first four chapters focus on phase retrieval from image transforms using a single frame. The next several chapters examine the local environment of a fringe pattern, give a broad picture of the phase estimation approach based on local polynomial phase modeling, cover temporal high-resolution phase evaluation methods, and pre

Design requirements for the SWIFT instrument

International Nuclear Information System (INIS)

Rahnama, P; McDade, I; Shepherd, G; Gault, W

2013-01-01

The Stratospheric Wind Interferometer for Transport studies (SWIFT) instrument is a proposed limb-viewing satellite instrument that employs the method of Doppler Michelson interferometry to measure stratospheric wind velocities and ozone densities in the altitude range of 15–45 km. The values of the main instrument parameters including filter system parameters and Michelson interferometer parameters are derived using simulations and analyses. The system design requirements for the instrument and spacecraft are presented and discussed. Some of the retrieval-imposed design requirements are also discussed. Critical design issues are identified. The design optimization process is described. The sensitivity of wind measurements to instrument characteristics is investigated including the impact on critical design issues. Using sensitivity analyses, the instrument parameters were iteratively optimized in order to meet the science objectives. It is shown that wind measurements are sensitive to the thermal sensitivity of the instrument components, especially the narrow filter and the Michelson interferometer. The optimized values of the main system parameters including Michelson interferometer optical path difference, instrument visibility, instrument responsivity and knowledge of spacecraft velocity are reported. This work also shows that the filter thermal drift and the Michelson thermal drift are two main technical risks. (paper)

Realization of an efficient coherent combination via Michelson cavity

Institute of Scientific and Technical Information of China (English)

2007-01-01

An intracavity coherent coupling Michelson erbium-doped fibre (EDF) laser (MCEDFL) is proposed and demonstrated. By using this laser system, we find a means to obtain a maximum power output at the same pumping power level. From the experiment based on fibre Bragg gratings (FBGs) with different reflectivities from 6% to 100%, we find that the reflectivity of the FBG plays a vital role in improving the performance of the MCEDFL. At the same time, the MCEDFL with a polarizer can be coherently combined effectively. This type of system, in principle, is compatible with other more powerful pumping methods, such as cladding pumping, and brings some novel perspectives to the realization of high power lasers.

The Michelson interferometer-how to detect invisible interference patterns

International Nuclear Information System (INIS)

Verovnik, Ivo; Likar, Andrej

2004-01-01

In a Michelson interferometer, the contrast of the interference pattern fades away due to incoherence of light when the mirrors are not in equidistant positions. We propose an experiment where the distance between the interference fringes can be determined, even when the difference in length of the interferometer arms is far beyond the coherence length of the light, i.e. when the interference pattern disappears completely for the naked eye. We used a semiconductor laser with two photodiodes as sensors, which enabled us to follow the fluctuations of the light intensity on the screen. The distance between invisible interference fringes was determined from periodic changes of the summed fluctuating signal, obtained by changing the distance between the two sensors

The Lindley paradox in optical interferometry

International Nuclear Information System (INIS)

Mauri, Camillo; Paris, Matteo G.A.

2016-01-01

The so-called Lindley paradox is a counterintuitive statistical effect where the Bayesian and frequentist approaches to hypothesis testing give radically different answers, depending on the choice of the prior distribution. In this paper we address the occurrence of the Lindley paradox in optical interferometry and discuss its implications for high-precision measurements. In particular, we focus on phase estimation by Mach–Zehnder interferometers and show how to mitigate the conflict between the two approaches by using suitable priors. - Highlights: • We address the occurence of Lindley paradox in interferometry and discuss its implications for high-precision measurements. • We show how to mitigate the conflict between Bayesian and frequentist approach to interferometry using suitable priors. • Our results apply to calibration of homodyne detectors for quantum tomography.

Refractometric sensor based on all-fiber coaxial Michelson and Mach-Zehnder interferometers for ethanol detection in fuel

International Nuclear Information System (INIS)

Mosquera, L; Osorio, Jonas H; Hayashi, Juliano G; Cordeiro, Cristiano M B

2011-01-01

A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zehnder interferometer and its application to measure ethanol concentration in gasoline.

Oxide thin films for spintronics application growth and characterization

OpenAIRE

Popovici, Nicoleta, 1973-

2009-01-01

Tese de doutoramento, Física (Física), Universidade de Lisboa, Faculdade de Ciências, 2009 During my PhD research I have synthesized thin films of a material known as a diluted magnetic semiconductor (DMS) using the pulsed laser deposition (PLD) technique. This material is envisioned to be of importance in the emerging field of spintronics where both the charge and the spin of the carriers can be combined to yield unique functionalities. It was envisaged that if spin polarized charge carri...

Summer School on Spintronics

CERN Document Server

Wolf, Stuart; Idzerda, Yves

2003-01-01

Stuart Wolf This book originated as a series of lectures that were given as part of a Summer School on Spintronics in the end of August, 1998 at Lake Tahoe, Nevada. It has taken some time to get these lectures in a form suitable for this book and so the process has been an iterative one to provide current information on the topics that are covered. There are some topics that have developed in the intervening years and we have tried to at least alert the readers to them in the Introduction where a rather complete set of references is provided to the current state of the art. The field of magnetism, once thought to be dead or dying, has seen a remarkable rebirth in the last decade and promises to get even more important as we enter the new millennium. This rebirth is due to some very new insight into how the spin degree of freedom of both electrons and nucleons can play a role in a new type of electronics that utilizes the spin in addition to or in place of the charge. For this new field to mature and prosper, ...

A calibration mechanism based on the principles of the Michelson interferometer micro-thrust test device

Science.gov (United States)

Yan, Biao; Wang, Hai; Yang, Chunlai; Wen, Li

2017-08-01

A micro-thrust test system based on Michelson interferometer was proposed and tested. The relationship between thrust and output voltage of the calibration component in the system was calculated and verified with numerical modeling. The fitting function of the calibration component was obtained, which will be tested during future thrust test experiments.

Quasi zero-background tunable diode laser absorption spectroscopy employing a balanced Michelson interferometer.

Science.gov (United States)

Guan, Zuguang; Lewander, Märta; Svanberg, Sune

2008-12-22

Tunable diode laser spectroscopy (TDLS) normally observes small fractional absorptive reductions in the light flux. We show, that instead a signal increase on a zero background can be obtained. A Michelson interferometer, which is initially balanced out in destructive interference, is perturbed by gas absorption in one of its arms. Both theoretical analysis and experimental demonstration show that the proposed zero-background TDLS can improve the achievable signal-to-noise ratio.

Atom Michelson interferometer on a chip using a Bose-Einstein condensate.

Science.gov (United States)

Wang, Ying-Ju; Anderson, Dana Z; Bright, Victor M; Cornell, Eric A; Diot, Quentin; Kishimoto, Tetsuo; Prentiss, Mara; Saravanan, R A; Segal, Stephen R; Wu, Saijun

2005-03-11

An atom Michelson interferometer is implemented on an "atom chip." The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

Atom Michelson interferometer on a chip using a Bose-Einstein condensate

International Nuclear Information System (INIS)

Wang Yingju; Anderson, Dana Z.; Cornell, Eric A.; Diot, Quentin; Kishimoto, Tetsuo; Segal, Stephen R.; Bright, Victor M.; Saravanan, R.A.; Prentiss, Mara; Wu Saijun

2005-01-01

An atom Michelson interferometer is implemented on an 'atom chip'. The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms

Speckle interferometry

Science.gov (United States)

Sirohi, Rajpal S.

2002-03-01

Illumination of a rough surface by a coherent monochromatic wave creates a grainy structure in space termed a speckle pattern. It was considered a special kind of noise and was the bane of holographers. However, its information-carrying property was soon discovered and the phenomenon was used for metrological applications. The realization that a speckle pattern carried information led to a new measurement technique known as speckle interferometry (SI). Although the speckle phenomenon in itself is a consequence of interference among numerous randomly dephased waves, a reference wave is required in SI. Further, it employs an imaging geometry. Initially SI was performed mostly by using silver emulsions as the recording media. The double-exposure specklegram was filtered to extract the desired information. Since SI can be configured so as to be sensitive to the in-plane displacement component, the out-of-plane displacement component or their derivatives, the interferograms corresponding to these were extracted from the specklegram for further analysis. Since the speckle size can be controlled by the F number of the imaging lens, it was soon realized that SI could be performed with electronic detection, thereby increasing its accuracy and speed of measurement. Furthermore, a phase-shifting technique can also be incorporated. This technique came to be known as electronic speckle pattern interferometry (ESPI). It employed the same experimental configurations as SI. ESPI found many industrial applications as it supplements holographic interferometry. We present three examples covering diverse areas. In one application it has been used to measure residual stress in a blank recordable compact disk. In another application, microscopic ESPI has been used to study the influence of relative humidity on paint-coated figurines and also the effect of a conservation agent applied on top of this. The final application is to find the defects in pipes. These diverse applications

Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature

NARCIS (Netherlands)

Schmuck, S.; Fessey, J.; Gerbaud, T.; Alper, B.; Beurskens, M. N. A.; de la Luna, E.; Sirinelli, A.; Zerbini, M.

2012-01-01

At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron

Development of a control scheme of homodyne detection for extracting ponderomotive squeezing from a Michelson interferometer

International Nuclear Information System (INIS)

Sakata, Shihori; Kawamura, Seiji; Sato, Shuichi; Somiya, Kentaro; Arai, Koji; Fukushima, Mitsuhiro; Sugamoto, Akio

2006-01-01

We developed a control scheme of homodyne detection. To operate the homodyne detector as easy as possible, a simple Michelson interferometer is used. Here a motivation that the control scheme of the homodyne detection is developed is for our future experiment of extracting the ponderomotively squeezed vacuum fluctuations. To obtain the best signalto- noise ratio using the homodyne detection, the homodyne phase should be optimized. The optimization of the homodyne phase is performed by changing a phase of a local oscillator for the homodyne detection from a point at which a signal is maximized. In fact, in this experiment, using the developed control scheme, we locked the Michelson interferometer with the homodyne detector and changed the phase of the local oscillator for the homodyne detection. Then, we measured signals quantity changed by changing the phase of the local oscillator for the homodyne detection. Here we used the output from the homodyne detection as the signal

Interferometry

Science.gov (United States)

Ridgway, Stephen; Wilson, Robert W.; Begelman, Mitchell C.; Bender, Peter; Burke, Bernard F.; Cornwell, Tim; Drever, Ronald; Dyck, H. Melvin; Johnston, Kenneth J.; Kibblewhite, Edward

1991-01-01

The following recommended programs are reviewed: (1) infrared and optical interferometry (a ground-based and space programs); (2) compensation for the atmosphere with adaptive optics (a program for development and implementation of adaptive optics); and (3) gravitational waves (high frequency gravitational wave sources (LIGO), low frequency gravitational wave sources (LAGOS), a gravitational wave observatory program, laser gravitational wave observatory in space, and technology development during the 1990's). Prospects for international collaboration and related issues are also discussed.

Physical interpretation of the fringe shift measured on Michelson interferometer in optical media

International Nuclear Information System (INIS)

Demjanov, V.V.

2010-01-01

The shift of the interference fringe in the Michelson interferometer is absent in vacuum but present in measurements performed in dielectric media with the refractive index greater than unity. This experimental observation induced me to interpret physical processes occurred in the Michelson interferometer in a conceptually new way. I rejected the generally accepted additive rule c±v for composition of the velocity v of the inertial body and the speed c of light as inapplicable in principle to non-inertial objects which electromagnetic waves just belong to. I used instead the non-relativistic formula of Fresnel for drag of light by a moving optical medium. This formula, and taking into account the physical effect of Lorentz contraction of the arm of interferometer, enabled me to construct the theoretical model that reproduces in essential features the parabolic dependence of the shift of the interference fringe on the dielectric permittivity of the light-carrying material. The Earth's speed relative to aether found from the experimental curve was estimated as 140-480 km/s. The range of the values refers to the projection of the speed on the horizontal plane of the experimental setup measured at various time of day and night.

Electrically switchable holographic liquid crystal/polymer Fresnel lens using a Michelson interferometer.

Science.gov (United States)

Jashnsaz, Hossein; Mohajerani, Ezeddin; Nemati, Hossein; Razavi, Seyed Hossein; Alidokht, Isa Ahmad

2011-06-10

A holographic technique for fabricating an electrically switchable liquid crystal/polymer composite Fresnel lens is reported. A Michelson interferometer is used to produce the required Fresnel pattern, by placing a convex lens into one path of the interferometer. Simplicity of the method and the possibility of fabricating different focal length lenses in a single arrangement are advantages of the method. The performance of the fabricated lens was demonstrated and its electro-optical properties were investigated for its primary focal length.

Holographic interferometry in construction analysis

Energy Technology Data Exchange (ETDEWEB)

Hartikainen, T.

1995-12-31

In this work techniques for visualizing phase and opaque objects by ruby laser interferometry are introduced. A leakage flow as a phase object is studied by holographic interferometry and the intensity distribution of the interferograms presenting the leakage flow are computer-simulated. A qualitative and quantitative analysis of the leakage flow is made. The analysis is based on the experimental and theoretical results presented in this work. The holographic setup and the double pass method for visualizing leakage flow are explained. A vibrating iron plate is the opaque object. Transient impact waves are generated by a pistol bullet on the iron plate and visualized by holographic interferometry. An apparatus with the capability of detecting and calculating the delays necessary for laser triggering is introduced. A time series of interferograms presenting elastic wave formation in an iron plate is shown. A computer-simulation of the intensity distributions of these interferograms is made. An analysis based on the computer-simulation and the experimental data of the transient elastic wave is carried out and the results are presented. (author)

A review on organic spintronic materials and devices: I. Magnetic field effect on organic light emitting diodes

Directory of Open Access Journals (Sweden)

Rugang Geng

2016-06-01

Full Text Available Organic spintronics is an emerging and potential platform for future electronics and display due to the intriguing properties of organic semiconductors (OSCs. For the past decade, studies have focused on three types of organic spintronic phenomena: (i magnetic field effect (MFE in organic light emitting diodes (OLEDs, where spin mixing between singlet and triplet polaron pairs (PP can be influenced by an external magnetic field leading to organic magnetoresistive effect (OMAR; (ii magnetoresistance (MR in organic spin valves (OSVs, where spin injection, transport, manipulation, and detection have been demonstrated; and (iii magnetoelectroluminescence (MEL bipolar OSVs or spin-OLEDs, where spin polarized electrons and holes are simultaneously injected into the OSC layer, leading to the dependence of electroluminescence intensity on relative magnetization of the electrodes. In this first of two review papers, we present major experimental results on OMAR studies and current understanding of OMAR using several spin dependent processes in organic semiconductors. During the discussion, we highlight some of the outstanding challenges in this promising research field. Finally, we provide an outlook on the future of organic spintronics.

A compact, high resolution Michelson interferometer for atmospheric spectroscopy in the near ultraviolet

Science.gov (United States)

Sander, Stanley P.; Cageao, Richard P.; Friedl, Randall R.

1993-01-01

A new, compact Fourier Transform Michelson interferometer (FTUV) with an apodized resolving power greater than 300,000 at 300 nm, high throughput and wide spectral coverage has been developed. The objectives include atmospheric spectroscopy (direct solar absorption and solar scattering) and laboratory spectroscopy of transient species. In this paper, we will briefly describe the prototype FTUV instrument and the results of preliminary laboratory investigations of OH and ClO spectra in emission and absorption.

The tempo-spatially modulated polarization atmosphere Michelson interferometer.

Science.gov (United States)

Zhang, ChunMin; Zhu, HuaChun; Zhao, Baochang

2011-05-09

A space-based tempo-spatially modulated polarization atmosphere Michelson interferometer (TSMPAMI) is described. It uses the relative movement between the TSMPAMI and the measured target to change optical path difference. The acquisition method of interferogram is presented. The atmospheric temperatures and horizontal winds can be derived from the optical observations. The measurement errors of the winds and temperatures are discussed through simulations. In the presence of small-scale structures of the atmospheric fields, the errors are found to be significantly influenced by the mismatch of the scenes observed by the adjacent CCD sub-areas aligned along the orbiter's track during successive measurements due to the orbital velocity and the exposure time. For most realistic conditions of the orbit and atmosphere, however, the instrument is proven suitable for measuring the atmospheric parameters. © 2011 Optical Society of America

A Michelson interferometer for X-rays and thermal neutrons

International Nuclear Information System (INIS)

Appel, A.

1992-01-01

The introduced interferometer consists of an LLL interferometer and a phase-displacing Bragg groove component. A part of the radiation path between the Lane mirrors in the Bragg grooves is replaced by a radiation path, whose wave number vector has a slightly different direction compared to the Lane case by the refraction correction. If the angles of incidence in the two grooves are different, then a difference in path is produced between the beams producing interference. This is the first X-ray interferometer which works like an optical Michelson interferometer. As there are no basic limits to resolution by absorption or dispersion, for example, it opens up the possibility of carrying out Fourier spectroscopy in the A wavelength range. (orig.) [de

Wide angle Michelson Doppler imaging interferometer. [measuring atmospheric emissions

Science.gov (United States)

Shepherd, G. G.

1980-01-01

The optical system, stepping control, phase and modulation depth, array detector, and directions sensor are described for a specialized type of Michelson interferometer which works at sufficiently high resolution to measure the line widths and Doppler shifts of naturally occurring atmospheric emissions. With its imaging capability, the instrument can potentially supply this data independently for each element of the 100 x 100 detector array. The experiment seeks: (1) to obtain vertical profiles of atmospheric winds and temperatures as functions of latitude by observing near the limb; (2) to acquire exploratory wind and temperature data on smaller scale structures in airglow irregularities and in auroral forms; and (3) to collaborate with other Spacelab experiments, such as barium cloud releases, in providing wind and temperature data.

The use of balanced homodyne and squeezed states for detecting weak optical signals in a Michelson interferometer

International Nuclear Information System (INIS)

Ben-Aryeh, Y.

2011-01-01

The possibility of using squeezed states and balanced homodyne detection of optical signals in a Michelson interferometer is discussed. The present analysis describes photon statistics measurements effects related to quadrature balanced homodyne detection showing the advantage of using this scheme for detecting weak optical signals.

Iterative supervirtual refraction interferometry

KAUST Repository

Al-Hagan, Ola

2014-05-02

In refraction tomography, the low signal-to-noise ratio (S/N) can be a major obstacle in picking the first-break arrivals at the far-offset receivers. To increase the S/N, we evaluated iterative supervirtual refraction interferometry (ISVI), which is an extension of the supervirtual refraction interferometry method. In this method, supervirtual traces are computed and then iteratively reused to generate supervirtual traces with a higher S/N. Our empirical results with both synthetic and field data revealed that ISVI can significantly boost up the S/N of far-offset traces. The drawback is that using refraction events from more than one refractor can introduce unacceptable artifacts into the final traveltime versus offset curve. This problem can be avoided by careful windowing of refraction events.

Iterative supervirtual refraction interferometry

KAUST Repository

Al-Hagan, Ola; Hanafy, Sherif M.; Schuster, Gerard T.

2014-01-01

In refraction tomography, the low signal-to-noise ratio (S/N) can be a major obstacle in picking the first-break arrivals at the far-offset receivers. To increase the S/N, we evaluated iterative supervirtual refraction interferometry (ISVI), which is an extension of the supervirtual refraction interferometry method. In this method, supervirtual traces are computed and then iteratively reused to generate supervirtual traces with a higher S/N. Our empirical results with both synthetic and field data revealed that ISVI can significantly boost up the S/N of far-offset traces. The drawback is that using refraction events from more than one refractor can introduce unacceptable artifacts into the final traveltime versus offset curve. This problem can be avoided by careful windowing of refraction events.

Emerging materials and devices in spintronic integrated circuits for energy-smart mobile computing and connectivity

International Nuclear Information System (INIS)

Kang, S.H.; Lee, K.

2013-01-01

A spintronic integrated circuit (IC) is made of a combination of a semiconductor IC and a dense array of nanometer-scale magnetic tunnel junctions. This emerging field is of growing scientific and engineering interest, owing to its potential to bring disruptive device innovation to the world of electronics. This technology is currently being pursued not only for scalable non-volatile spin-transfer-torque magnetoresistive random access memory, but also for various forms of non-volatile logic (Spin-Logic). This paper reviews recent advances in spintronic IC. Key discoveries and breakthroughs in materials and devices are highlighted in light of the broader perspective of their application in low-energy mobile computing and connectivity systems, which have emerged as leading drivers for the prevailing electronics ecosystem

Low intrinsic carrier density LSMO/Alq3/AlOx/Co organic spintronic devices

Science.gov (United States)

Riminucci, Alberto; Graziosi, Patrizio; Calbucci, Marco; Cecchini, Raimondo; Prezioso, Mirko; Borgatti, Francesco; Bergenti, Ilaria; Dediu, Valentin Alek

2018-04-01

The understanding of spin injection and transport in organic spintronic devices is still incomplete, with some experiments showing magnetoresistance and others not detecting it. We have investigated the transport properties of a large number of tris-(8-hydroxyquinoline)aluminum-based organic spintronic devices with an electrical resistance greater than 5 MΩ that did not show magnetoresistance. Their transport properties could be described satisfactorily by known models for organic semiconductors. At high voltages (>2 V), the results followed the model of space charge limited current with a Poole-Frenkel mobility. At low voltages (˜0.1 V), that are those at which the spin valve behavior is usually observed, the charge transport was modelled by nearest neighbor hopping in intra-gap impurity levels, with a charge carrier density of n0 = (1.44 ± 0.21) × 1015 cm-3 at room temperature. Such a low carrier density can explain why no magnetoresistance was observed.

Experiments on the Porch Swing Bearing of Michelson Interferometer for Low Resolution FTIR

OpenAIRE

Tuomas Välikylä; Jyrki Kauppinen

2013-01-01

Porch swing bearing for the linear motion of the mirror in Michelson interferometer for mid-infrared low resolution Fourier transform spectrometer was studied experimentally using the modulation depth of the collimated laser beam. The mirror tilting was measured to be lower than 5 μrad over 3 mm mirror travel using two different bearings assemblies. Additionally, the manufacturing tolerances of the bearing type were proved to be loose enough not to limit the interferometer application. These ...

Vibration insensitive interferometry

Science.gov (United States)

Millerd, James; Brock, Neal; Hayes, John; Kimbrough, Brad; North-Morris, Michael; Wyant, James C.

2017-11-01

The largest limitation of phase-shifting interferometry for optical testing is the sensitivity to the environment, both vibration and air turbulence. An interferometer using temporal phase-shifting is very sensitive to vibration because the various phase shifted frames of interferometric data are taken at different times and vibration causes the phase shifts between the data frames to be different from what is desired. Vibration effects can be reduced by taking all the phase shifted frames simultaneously and turbulence effects can be reduced by averaging many measurements. There are several techniques for simultaneously obtaining several phase-shifted interferograms and this paper will discuss two such techniques: 1) Simultaneous phase-shifting interferometry on a single detector array (PhaseCam) and 2) Micropolarizer phase-shifting array. The application of these techniques for the testing of large optical components, measurement of vibrational modes, the phasing of segmented optical components, and the measurement of deformations of large diffuse structures is described.

Resolving fringe ambiguities of a wide-field Michelson interferometer using visibility measurements of a noncollimated laser beam.

Science.gov (United States)

Wan, Xiaoke; Wang, Ji; Ge, Jian

2009-09-10

An actively stabilized interferometer with a constant optical path difference is a key element in long-term astronomical observation, and resolving interference fringe ambiguities is important to produce high-precision results for the long term. We report a simple and reliable method of resolving fringe ambiguities of a wide-field Michelson interferometer by measuring the interference visibility of a noncollimated single-frequency laser beam. Theoretical analysis shows that the interference visibility is sensitive to a subfringe phase shift, and a wide range of beam arrangements is suitable for real implementation. In an experimental demonstration, a Michelson interferometer has an optical path difference of 7 mm and a converging monitoring beam has a numerical aperture of 0.045 with an incidental angle of 17 degrees. The resolution of visibility measurements corresponds to approximately 1/16 fringe in the interferometer phase shift. The fringe ambiguity-free region is extended over a range of approximately 100 fringes.

Digital holographic amplification of interferograms in the Michelson interferometer using the phase-only LCOS modulator

Science.gov (United States)

Balbekin, Nikolay; Petrov, Nikolay; Pul'kin, Sergey; Shoev, Vladislav; Sevryugin, Alexander; Tursunov, Ibrohim; Venediktov, Dmitrii; Venediktov, Vladimir

2017-10-01

The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific "hooks", whose curvature provides the information about the atomic oscillator force. The holographic amplification "smoothes" the hooks and thus makes their analysis much simpler.

Reduction of quantum noise in the Michelson interferometer by use of squeezed vacuum states

International Nuclear Information System (INIS)

Assaf, Ohad; Ben-Aryeh, Yacob

2002-01-01

We develop further the unified model for treating photon-counting and radiation-pressure fluctuations in the Michelson interferometer with input of squeezed vacuum state. The dependence of the quantum fluctuations on the phase of the input light is calculated. The analysis is restricted to a single-mode interferometer, but generalized in a way that includes both harmonic-oscillator and floating mirrors. We compare our results with those of other authors

Interferometry and synthesis in radio astronomy

CERN Document Server

Thompson, A Richard; Swenson Jr , George W

2017-01-01

This book is open access under a CC BY-NC 4.0 license. The third edition of this indispensable book in radio interferometry provides extensive updates to the second edition, including results and technical advances from the past decade; discussion of arrays that now span the full range of the radio part of the electromagnetic spectrum observable from the ground, 10 MHz to 1 THz; an analysis of factors that affect array speed; and an expanded discussion of digital signal-processing techniques and of scintillation phenomena and the effects of atmospheric water vapor on image distortion, among many other topics. With its comprehensiveness and detailed exposition of all aspects of the theory and practice of radio interferometry and synthesis imaging, this book has established itself as a standard reference in the field. It begins with an overview of the basic principles of radio astronomy, a short history of the development of radio interferometry, and an elementary discussion of the operation of an interferomete...

Samuel A. Werner Pioneer of Neutron Interferometry

International Nuclear Information System (INIS)

Klein, Anthony

2005-01-01

Full text: In 1975, Sam Werner and his collaborators on the staff of the Scientific Laboratory of the Ford Motor Company carried out one of the pioneering experiments in neutron interferometry at the 2MW University of Michigan research reactor. It was the famous COW Experiment on gravitationally induced quantum interference. Shortly thereafter he moved to the University of Missouri in Columbia, to set up a program of neutron scattering research, including neutron interferometry. In the 25 years until his retirement a large number of beautiful experiments have been performed by Sam, with his group, his numerous students and many international collaborators. The Interferometry and Coherence session at this conference has been organized in his honour and the collected papers presented by his friends, collaborators and former students form his Festschrift. (author)

Materials for spintronic: Room temperature ferromagnetism in Zn-Mn-O interfaces

International Nuclear Information System (INIS)

Quesada, A.; Garcia, M.A.; Crespo, P.; Hernando, A.

2006-01-01

In this paper we study the room temperature ferromagnetism reported on Mn-doped ZnO and ascribed to spin polarization of conduction electrons. We experimentally show that the ferromagnetic behaviour is associated to the coexistence of Mn 3+ and Mn +4 in MnO 2 grains where diffusion of Zn promotes the Mn 4+→ Mn 3+ reduction. Potential uses of this material in spintronic devices are analysed

Field-widened Michelson interferometer for spectral discrimination in high-spectral-resolution lidar: theoretical framework.

Science.gov (United States)

Cheng, Zhongtao; Liu, Dong; Luo, Jing; Yang, Yongying; Zhou, Yudi; Zhang, Yupeng; Duan, Lulin; Su, Lin; Yang, Liming; Shen, Yibing; Wang, Kaiwei; Bai, Jian

2015-05-04

A field-widened Michelson interferometer (FWMI) is developed to act as the spectral discriminator in high-spectral-resolution lidar (HSRL). This realization is motivated by the wide-angle Michelson interferometer (WAMI) which has been used broadly in the atmospheric wind and temperature detection. This paper describes an independent theoretical framework about the application of the FWMI in HSRL for the first time. In the framework, the operation principles and application requirements of the FWMI are discussed in comparison with that of the WAMI. Theoretical foundations for designing this type of interferometer are introduced based on these comparisons. Moreover, a general performance estimation model for the FWMI is established, which can provide common guidelines for the performance budget and evaluation of the FWMI in the both design and operation stages. Examples incorporating many practical imperfections or conditions that may degrade the performance of the FWMI are given to illustrate the implementation of the modeling. This theoretical framework presents a complete and powerful tool for solving most of theoretical or engineering problems encountered in the FWMI application, including the designing, parameter calibration, prior performance budget, posterior performance estimation, and so on. It will be a valuable contribution to the lidar community to develop a new generation of HSRLs based on the FWMI spectroscopic filter.

Electric field-induced magnetoresistance in spin-valve/piezoelectric multiferroic laminates for low-power spintronics

International Nuclear Information System (INIS)

Huong Giang, D.T.; Thuc, V.N.; Duc, N.H.

2012-01-01

Electric field-induced magnetic anisotropy has been realized in the spin-valve-based {Ni 80 Fe 20 /Cu/Fe 50 Co 50 /IrMn}/piezoelectric multiferroic laminates. In this system, electric-field control of magnetization is accomplished by strain mediated magnetoelectric coupling. Practically, the magnetization in the magnetostrictive FeCo layer of the spin-valve structure rotates under an effective compressive stress caused by the inverse piezoelectric effect in external electrical fields. This phenomenon is evidenced by the magnetization and magnetoresistance changes under the electrical field applied across the piezoelectric layer. The result shows great potential for advanced low-power spintronic devices. - Highlights: ► Investigate electric field-induced magnetic anisotropy in spin-valve/piezoelectric. ► Magnetization, magnetoresistance changes under electric field across piezoelectric. ► Magnetization in magnetostrictive FeCo-layer rotates under a compressive stress. ► This advance shows great implications for low-power electronics and spintronics.

Pipeline monitoring with interferometry in non-arid regions

Energy Technology Data Exchange (ETDEWEB)

McCardle, Adrian; Rabus, Bernhard; Ghuman, Parwant [MacDonald Dettwiler, Richmond, BC (Canada); Freymueller, Jeff T. [University of Alaska, Fairbanks (United States)

2005-07-01

Interferometry has become a proven technique for accurately measuring ground movements caused by subsidence, landslides, earthquakes and volcanoes. Using space borne sensors such as the ERS, ENVISAT and RADARSAT satellites, ground deformation can be monitored on a millimeter level. Traditionally interferometry has been limited to arid areas however new technology has allowed for successful monitoring in vegetated regions and areas of changing land-cover. Analysis of ground movement of the Trans-Alaskan pipeline demonstrates how these techniques can offer pipeline engineers a new tool for observing potential dangers to pipeline integrity. Results from Interferometric Point Target Analysis were compared with GPS measurements and speckle tracking interferometry was demonstrated to measure a major earthquake. (author)

Time-delay interferometry for LISA

International Nuclear Information System (INIS)

Tinto, Massimo; Estabrook, F.B.; Armstrong, J.W.

2002-01-01

LISA (Laser Interferometer Space Antenna) is a mission to detect and study low-frequency cosmic gravitational radiation through its influence on the phases or frequencies of laser beams exchanged between three remote spacecraft. We previously showed how, with lasers of identical frequencies on stationary spacecraft, the measurement of twelve time series of Doppler shifts could be combined to cancel exactly the phase noise of the lasers and the Doppler fluctuations due to noninertial motions of the six optical benches, while preserving gravitational wave signals. Here we generalize those results on gravitational wave detection with time-delay interferometry to the expected LISA instrument. The six lasers have different center frequencies (in the nominal LISA configuration these center frequencies may well differ by several hundred megahertz) and the distances between spacecraft pairs will change with time (these slowly varying orbital Doppler shifts are expected to be up to tens of megahertz). We develop time-delay data combinations which, as previously, preserve gravitational waves and exactly cancel the leading noise source (phase fluctuations of the six lasers); these data combinations then imply transfer functions for the remaining system noises. Using these, we plot frequency and phase power spectra for modeled system noises in the unequal Michelson combination X and the symmetric Sagnac combination ζ. Although optical bench noise can no longer be cancelled exactly, with the current LISA specifications it is suppressed to negligible levels. It is known that the presently anticipated laser center frequency differences and the orbital Doppler drifts introduce another source of phase noise, arising from the onboard oscillators required to track the photodetector fringes. For the presently planned mission, our analysis indeed demonstrates that noise from current-generation ultrastable oscillators would, if uncorrected, dominate the LISA noise budget. To meet the

Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

Science.gov (United States)

Wan, Xiaoke; Ge, Jian

2012-09-15

A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

Parsimonious Surface Wave Interferometry

KAUST Repository

Li, Jing

2017-10-24

To decrease the recording time of a 2D seismic survey from a few days to one hour or less, we present a parsimonious surface-wave interferometry method. Interferometry allows for the creation of a large number of virtual shot gathers from just two reciprocal shot gathers by crosscoherence of trace pairs, where the virtual surface waves can be inverted for the S-wave velocity model by wave-equation dispersion inversion (WD). Synthetic and field data tests suggest that parsimonious wave-equation dispersion inversion (PWD) gives S-velocity tomograms that are comparable to those obtained from a full survey with a shot at each receiver. The limitation of PWD is that the virtual data lose some information so that the resolution of the S-velocity tomogram can be modestly lower than that of the S-velocity tomogram inverted from a conventional survey.

Parsimonious Surface Wave Interferometry

KAUST Repository

Li, Jing; Hanafy, Sherif; Schuster, Gerard T.

2017-01-01

To decrease the recording time of a 2D seismic survey from a few days to one hour or less, we present a parsimonious surface-wave interferometry method. Interferometry allows for the creation of a large number of virtual shot gathers from just two reciprocal shot gathers by crosscoherence of trace pairs, where the virtual surface waves can be inverted for the S-wave velocity model by wave-equation dispersion inversion (WD). Synthetic and field data tests suggest that parsimonious wave-equation dispersion inversion (PWD) gives S-velocity tomograms that are comparable to those obtained from a full survey with a shot at each receiver. The limitation of PWD is that the virtual data lose some information so that the resolution of the S-velocity tomogram can be modestly lower than that of the S-velocity tomogram inverted from a conventional survey.

Resolving power test of 2-D K+ K+ interferometry

International Nuclear Information System (INIS)

Padula, Sandra S.; Roldao, Christiane G.

1999-01-01

Adopting a procedure previously proposed to quantitatively study pion interferometry 1 , an equivalent 2-D X 2 analysis was performed to test the resolving power of that method when applied to less favorable conditions, when no significant contribution from long lived resonances is expected, as in kaon interferometry. For that purpose, use is made of the preliminary E859 K + K + interferometry data from Si+Au collisions at 14.6 A GeV/c. Less sensitivity is achieved in the present case, although it is shown that it is still possible to distinguish two distinct decoupling geometries. (author)

Nanonewton force measurement using a modified Michelson interferometer

International Nuclear Information System (INIS)

Tahviliyan, Masoud; Charsooghi, Mohammad A; Akhlaghi, Ehsan A; Taghi Tavassoly, Mohammad

2017-01-01

In this paper, we introduce a new method to measure forces in the nanonewton range. The method is based on modification of a Michelson interferometer in which the rigid mirrors are replaced with two thin rod-like mirrors. One of the rod-like mirrors is fixed at both ends and the other has one free end. As the mirror with free end deflects in response to an applied force the spatial interference pattern is changed. Analysis of the interference fringes provides a readout of the rod deflection and thereby the applied force. The device is calibrated by applying known forces to the mirror with a free end and measuring the resulting displacement. Two different methods, mechanical and electrostatic, are used for calibration. The precision of the measurements and the propagation of the calibration uncertainty are investigated. The results show that this optical method is a good candidate for detecting small forces in the nanonewton range. (paper)

WAMDII: The Wide Angle Michelson Doppler Imaging Interferometer

Science.gov (United States)

1992-01-01

As part of an effort to learn more about the upper atmosphere and how it is linked to the weather experienced each day, NASA and NRCC are jointly sponsoring the Wide Angle Michelson Doppler Imaging Interferometer (WAMDII) Mission. WAMDII will measure atmospheric temperature and wind speed in the upper atmosphere. In addition to providing data on the upper atmosphere, the wind speed and temperature readings WAMDII takes will also be highly useful in developing and updating computer simulated models of the upper atmosphere. These models are used in the design and testing of equipment and software for Shuttles, satellites, and reentry vehicles. In making its wind speed and temperature measurements, WAMDII examines the Earth's airglow, a faint photochemical luminescence caused by the influx of solar ultraviolet energy into the upper atmosphere. During periods of high solar flare activity, the amount of this UV energy entering the upper atmosphere increases, and this increase may effect airglow emissions.

Holographic interferometry of high pressure

International Nuclear Information System (INIS)

McIlwain, M.E.

1987-01-01

Measurements in turbulent flows have been historically performed using various types of probes and optical diagnostic methods. In general, probes suffer from plasma perturbation effects and are single point determination methods. Optical methods appear to be better suited to determinations in turbulent flows, however interpretation of the resulting data can often be complex. Methods such as laser Doppler anemometry, which relies on entrained particles, suffers from the fact that particles small enough to be swept along by the plasma are usually melted or sublimed in the plasma. Light refraction or diffraction methods such as shadow photography, interferometry, and holography have also been used to observe plasma flows. These methods typically suffer from the difficulty of interpreting line of sight images and obtaining quantitative data. A new method based on multi-pass holographic interferometry will be discussed. This method has certain advantages which can significantly simplify the complexity of line of sight interferometry image deconvolution. When the method employs high speed cinematography, time resolved images of the plasma flow can be obtained. This method has been applied to both transferred and non-transferred arcs and various types of DC-plasma torch produced jets. These studies and conclusions as to the usefulness of the technique are presented

Absolute marine gravimetry with matter-wave interferometry.

Science.gov (United States)

Bidel, Y; Zahzam, N; Blanchard, C; Bonnin, A; Cadoret, M; Bresson, A; Rouxel, D; Lequentrec-Lalancette, M F

2018-02-12

Measuring gravity from an aircraft or a ship is essential in geodesy, geophysics, mineral and hydrocarbon exploration, and navigation. Today, only relative sensors are available for onboard gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints. Atom interferometry is a promising technology to obtain onboard absolute gravimeter. But, despite high performances obtained in static condition, no precise measurements were reported in dynamic. Here, we present absolute gravity measurements from a ship with a sensor based on atom interferometry. Despite rough sea conditions, we obtained precision below 10 -5  m s -2 . The atom gravimeter was also compared with a commercial spring gravimeter and showed better performances. This demonstration opens the way to the next generation of inertial sensors (accelerometer, gyroscope) based on atom interferometry which should provide high-precision absolute measurements from a moving platform.

Measuring the separation of the sodium D-doublet with a Michelson interferometer

Science.gov (United States)

D'Anna, M.; Corridoni, T.

2018-01-01

Revisiting a method proposed by Fizeau in 1862, in this paper we measure the separation of the Na-doublet (the wavelength difference {{Δ }}λ between the two emission D-lines of the sodium spectrum) with a didactical Michelson interferometer. We describe the setup, how the measurements have been done and develop a mathematical model in order to explain the principal features of the collected data. Discussing the limits of this model, we suggest further experimental and theoretical extensions of the experience, also focusing on the didactical aspects to show how this experiment could bring advanced modern physics topics into high schools.

Fiber optic interferometry for industrial process monitoring and control applications

Science.gov (United States)

Marcus, Michael A.

2002-02-01

Over the past few years we have been developing applications for a high-resolution (sub-micron accuracy) fiber optic coupled dual Michelson interferometer-based instrument. It is being utilized in a variety of applications including monitoring liquid layer thickness uniformity on coating hoppers, film base thickness uniformity measurement, digital camera focus assessment, optical cell path length assessment and imager and wafer surface profile mapping. The instrument includes both coherent and non-coherent light sources, custom application dependent optical probes and sample interfaces, a Michelson interferometer, custom electronics, a Pentium-based PC with data acquisition cards and LabWindows CVI or LabView based application specific software. This paper describes the development evolution of this instrument platform and applications highlighting robust instrument design, hardware, software, and user interfaces development. The talk concludes with a discussion of a new high-speed instrument configuration, which can be utilized for high speed surface profiling and as an on-line web thickness gauge.

Multi-parameter optimization of a nanomagnetic system for spintronic applications

International Nuclear Information System (INIS)

Morales Meza, Mishel; Zubieta Rico, Pablo F.; Horley, Paul P.; Sukhov, Alexander; Vieira, Vítor R.

2014-01-01

Magnetic properties of nano-particles feature many interesting physical phenomena that are essentially important for the creation of a new generation of spin-electronic devices. The magnetic stability of the nano-particles can be improved by formation of ordered particle arrays, which should be optimized over several parameters. Here we report successful optimization regarding inter-particle distance and applied field frequency allowing to obtain about three-times reduction of coercivity of a particle array compared to that of a single particle, which opens new perspectives for development of new spintronic devices

Multi-parameter optimization of a nanomagnetic system for spintronic applications

Energy Technology Data Exchange (ETDEWEB)

Morales Meza, Mishel [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Zubieta Rico, Pablo F. [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV) Querétaro, Libramiento Norponiente 2000, Fracc. Real de Juriquilla, 76230 Querétaro (Mexico); Horley, Paul P., E-mail: paul.horley@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Sukhov, Alexander [Institut für Physik, Martin-Luther Universität Halle-Wittenberg, 06120 Halle (Saale) (Germany); Vieira, Vítor R. [Centro de Física das Interacções Fundamentais (CFIF), Instituto Superior Técnico, Universidade Técnica de Lisboa, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal)

2014-11-15

Magnetic properties of nano-particles feature many interesting physical phenomena that are essentially important for the creation of a new generation of spin-electronic devices. The magnetic stability of the nano-particles can be improved by formation of ordered particle arrays, which should be optimized over several parameters. Here we report successful optimization regarding inter-particle distance and applied field frequency allowing to obtain about three-times reduction of coercivity of a particle array compared to that of a single particle, which opens new perspectives for development of new spintronic devices.

A procedure for noise uncoupling in laser interferometry

CERN Document Server

Barone, F; Rosa, R D; Eleuteri, A; Milano, L; Qipiani, K

2002-01-01

A numerical procedure for noise recognition and uncoupling is described. The procedure is applied to a Michelson interferometer and is effective in seismic and acoustic noise uncoupling from the output signal of the interferometer. Due to the low data flow coming from the instrumentation this uncoupling can be performed in real time and it is useful as a data quality procedure for interferometer data output.

Precision Geodesy via Radio Interferometry.

Science.gov (United States)

Hinteregger, H F; Shapiro, I I; Robertson, D S; Knight, C A; Ergas, R A; Whitney, A R; Rogers, A E; Moran, J M; Clark, T A; Burke, B F

1972-10-27

Very-long-baseline interferometry experiments, involving observations of extragalactic radio sources, were performed in 1969 to determine the vector separations between antenna sites in Massachusetts and West Virginia. The 845.130-kilometer baseline was estimated from two separate experiments. The results agreed with each other to within 2 meters in all three components and with a special geodetic survey to within 2 meters in length; the differences in baseline direction as determined by the survey and by interferometry corresponded to discrepancies of about 5 meters. The experiments also yielded positions for nine extragalactic radio sources, most to within 1 arc second, and allowed the hydrogen maser clocks at the two sites to be synchronized a posteriori with an uncertainty of only a few nanoseconds.

Performance evaluation of a dual fringe-imaging Michelson interferometer for air parameter measurements with a 355 nm Rayleigh-Mie lidar.

Science.gov (United States)

Cézard, Nicolas; Dolfi-Bouteyre, Agnès; Huignard, Jean-Pierre; Flamant, Pierre H

2009-04-20

A new concept of spectrum analyzer is proposed for short-range lidar measurements in airborne applications. It implements a combination of two fringe-imaging Michelson interferometers to analyze the Rayleigh-Mie spectrum backscattered by molecules and particles at 355 nm. The objective is to perform simultaneous measurements of four variables: the air speed, the air temperature and density, and the particle scattering ratio. The Cramer-Rao bounds are calculated to evaluate the best expectable measurement accuracies. The performance optimization shows that a Michelson interferometer with a path difference of 3 cm is optimal for air speed measurements in clear air. To optimize density, temperature, and scattering ratio measurements, the second interferometer should be set to a path difference of 10 cm at least; 20 cm would be better to be less sensitive to the actual Rayleigh-Brillouin line shape.

Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature.

Science.gov (United States)

Schmuck, S; Fessey, J; Gerbaud, T; Alper, B; Beurskens, M N A; de la Luna, E; Sirinelli, A; Zerbini, M

2012-12-01

At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The current state of the interferometer hardware, the calibration setup, and the analysis technique for calibration and plasma operation are described. A new, full-system, absolute calibration employing continuous data acquisition has been performed recently and the calibration method and results are presented. The noise level in the measurement is very low and as a result the electron cyclotron emission spectrum and thus the spatial profile of the electron temperature are determined to within ±5% and in the most relevant region to within ±2%. The new calibration shows that the absolute response of the system has decreased by about 15% compared to that measured previously and possible reasons for this change are presented. Temperature profiles measured with the Michelson interferometer are compared with profiles measured independently using Thomson scattering diagnostics, which have also been recently refurbished and recalibrated, and agreement within experimental uncertainties is obtained.

Improvement on a Michelson interferometer for bunch length measurement of a femtosecond accelerator

International Nuclear Information System (INIS)

Lin Xuling; Bei Hua; Zhang Jianbing; Dai Zhimin

2009-01-01

Based on the femtosecond accelerator facility at Shanghai Institute of Applied Physics (SINAP), a conventional far-infrared Michelson interferometer was built to measure the bunch length by means of optical autocorrelation. However, according to the preliminary experiment result, the resolution of interferometer is not good enough, because the mirror-driving mechanism makes the moving mirror tend to tilt or wobble as it retards. Considering of the allowable errors, we calculate the maximum allowable titling angle of the moving mirror, and discuss the alignment plan in this paper. (authors)

Active feedback regulation of a Michelson interferometer to achieve zero-background absorption measurements.

Science.gov (United States)

Lundin, Patrik; Guan, Zuguang; Svanberg, Sune

2011-01-20

An active phase-controlling scheme based on a proportional-integral-derivative-controlled piezoelectric transducer is presented with the purpose of stabilizing a quasi-zero-background absorption spectrometer. A fiber-based balanced Michelson interferometer is used, and absorption due to a gas sample in one of its arms results in an increased light signal to a detector, which otherwise, thanks to destructive interference, experiences a very low light level. With the presented approach, the sensitivity of already potent absorption measurement techniques, e.g., based on modulation, could be improved even further.

Development of Speckle Interferometry Algorithm and System

International Nuclear Information System (INIS)

Shamsir, A. A. M.; Jafri, M. Z. M.; Lim, H. S.

2011-01-01

Electronic speckle pattern interferometry (ESPI) method is a wholefield, non destructive measurement method widely used in the industries such as detection of defects on metal bodies, detection of defects in intergrated circuits in digital electronics components and in the preservation of priceless artwork. In this research field, this method is widely used to develop algorithms and to develop a new laboratory setup for implementing the speckle pattern interferometry. In speckle interferometry, an optically rough test surface is illuminated with an expanded laser beam creating a laser speckle pattern in the space surrounding the illuminated region. The speckle pattern is optically mixed with a second coherent light field that is either another speckle pattern or a smooth light field. This produces an interferometric speckle pattern that will be detected by sensor to count the change of the speckle pattern due to force given. In this project, an experimental setup of ESPI is proposed to analyze a stainless steel plate using 632.8 nm (red) wavelength of lights.

Isotope Analysis of Uranium by Interferometry; Analyse isotopique de l'uranium par interferometrie

Energy Technology Data Exchange (ETDEWEB)

Leicknam, J P [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1962-07-01

Among the optical methods which may be used to make isotopic measurements of {sup 235}U interferometry gives promising results. An apparatus is described which has a photomultiplier as receiver; the source must therefore have characteristics (intensity, stability, fineness of emitted rays) which have led to the use of electrode-less discharge tubes whose methods of production and excitation are given. An example of calibration is given. (author) [French] Parmi les methodes optiques permettant le dosage isotopique de l'uranium 235, l'interferometrie est une technique qui donne des resultats prometteurs. On decrit ici un appareil ayant un photo-multiplicateur comme recepteur; la source doit donc avoir des caracteristiques (intensite, stabilite, finesse des raies emises) qui ont conduit a utiliser des tubes a decharge sans electrode dont on indique la fabrication et le mode d'excitation. Un exemple d'etalonnage est enfin donne. (auteur)

Improved operation of the Michelson interferometer ECE diagnostic on DIII-D

International Nuclear Information System (INIS)

Austin, M.E.; Ellis, R.F.; Doane, J.L.; James, R.A.

1996-05-01

The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and reduction of calibration error to around 5%. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter wavelength frequency and very stable transmission characteristics over time. Further reduction in error has been realized through special signal processing of the calibration and plasma interferograms

Investigation of michelson interferometer for volatile organic compound sensor

International Nuclear Information System (INIS)

Marzuarman; Rivai, Muhammad; Sardjono, Tri Arief; Purwanto, Djoko

2017-01-01

The sensor device is required to monitor harmful gases in the environments and industries. Many volatile organic compounds adsorbed on the sensor material will result in changes of the optical properties including the refractive index and the film thickness. This study designed and realized a vapor detection device using the principle of Michelson Interferometer. The laser light beamed with a wavelength of 620 nm was divided by using a beam splitter. Interference occurredwhen the two separated lights were recombined. The phase difference between the two beams determined whether the interference would destruct or construct each other to produce the curved fringes. The vapor samples used in these experiments were ethanol and benzene. The results showed that the ethanol concentration of 1611-32210 ppm produced a fringe shift of 197 pixels, while the concentration of benzene of 964-19290 ppm produced a fringe shift of 273 pixels. (paper)

Highly accurate Michelson type wavelength meter that uses a rubidium stabilized 1560 nm diode laser as a wavelength reference

International Nuclear Information System (INIS)

Masuda, Shin; Kanoh, Eiji; Irisawa, Akiyoshi; Niki, Shoji

2009-01-01

We investigated the accuracy limitation of a wavelength meter installed in a vacuum chamber to enable us to develop a highly accurate meter based on a Michelson interferometer in 1550 nm optical communication bands. We found that an error of parts per million order could not be avoided using famous wavelength compensation equations. Chromatic dispersion of the refractive index in air can almost be disregarded when a 1560 nm wavelength produced by a rubidium (Rb) stabilized distributed feedback (DFB) diode laser is used as a reference wavelength. We describe a novel dual-wavelength self-calibration scheme that maintains high accuracy of the wavelength meter. The method uses the fundamental and second-harmonic wavelengths of an Rb-stabilized DFB diode laser. Consequently, a highly accurate Michelson type wavelength meter with an absolute accuracy of 5x10 -8 (10 MHz, 0.08 pm) over a wide wavelength range including optical communication bands was achieved without the need for a vacuum chamber.

New methods for the investigation of phase objects by digital Speckle-pattern-interferometry

International Nuclear Information System (INIS)

Fliesser, W.

1996-11-01

This work shows new possibilities for spatially resolved interferometric investigations of transparent objects (phase-objects) applying the method of Digital-Speckle-Pattern-Interferometry (DSPI). A feedback-system using an additional MICHELSON-interferometer in the reference-arm of the Speckle-interferometer was installed for computer-controlled digitalization of the primary interferograms at defined phase-shifts. A special program for interferogram analysis allows the evaluation of two-dimensional phase distributions using different phase-stepping algorithms as 3-Frame-, 4-Frame-, CARRE-, 4+1-Frame- and 6+1-Frame technique. Special DSPI-setups with modified MACH-ZEHNDER-interferometers were used to check the system. In some basic experiments the temperature distribution in a cross section of convective heat-flows of air was measured. As an application on plasma-diagnostics the space-resolved electron density in a high pressure mercury lamp was determined using two-wavelength-DSPI. To increase the sensitivity of the method a Nd-YAG-laser at 1064 nm was employed in addition to an Ar + -laser at 488 Nm. The electron density in one cross-section of the lamp could be calculated by ABEL-inversion of the measured phase data. A multi-directional optical setup with a special mirror system was developed to investigate asymmetric phase-objects by DSPI. The setup allows to store six primary interferograms from different directions in one step, while using a single reference-beam only. Helium flows in air with different flow geometries were used as phase-objects. Tomographic reconstruction procedures such as the convolution-method yield the distributions of the refractive-index and the related helium concentrations in selected cross sections of the flow. (author)

Spectral interferometry including the effect of transparent thin films to measure distances and displacements

International Nuclear Information System (INIS)

Hlubina, P.

2004-01-01

A spectral-domain interferometric technique is applied for measuring mirror distances and displacements in a dispersive Michelson interferometer when the effect of transparent thin films coated onto the interferometer beam splitter and compensator is known. We employ a low-resolution spectrometer in two experiments with different amounts of dispersion in a Michelson interferometer that includes fused-silica optical sample. Knowing the thickness of the optical sample and the nonlinear phase function of the thin films, the positions of the interferometer mirror are determined precisely by a least-squares fitting of the theoretical spectral interferograms to the recorded ones. We compare the results of the processing that include and do not include the effect of transparent thin films (Author)

Accessing High Spatial Resolution in Astronomy Using Interference Methods

Science.gov (United States)

Carbonel, Cyril; Grasset, Sébastien; Maysonnave, Jean

2018-04-01

In astronomy, methods such as direct imaging or interferometry-based techniques (Michelson stellar interferometry for example) are used for observations. A particular advantage of interferometry is that it permits greater spatial resolution compared to direct imaging with a single telescope, which is limited by diffraction owing to the aperture of the instrument as shown by Rueckner et al. in a lecture demonstration. The focus of this paper, addressed to teachers and/or students in high schools and universities, is to easily underline both an application of interferometry in astronomy and stress its interest for resolution. To this end very simple optical experiments are presented to explain all the concepts. We show how an interference pattern resulting from the combined signals of two telescopes allows us to measure the distance between two stars with a resolution beyond the diffraction limit. Finally this work emphasizes the breathtaking resolution obtained in state-of-the-art instruments such as the VLTi (Very Large Telescope interferometer).

Parsimonious Refraction Interferometry and Tomography

KAUST Repository

Hanafy, Sherif; Schuster, Gerard T.

2017-01-01

We present parsimonious refraction interferometry and tomography where a densely populated refraction data set can be obtained from two reciprocal and several infill shot gathers. The assumptions are that the refraction arrivals are head waves

Displacement measurement using an optoelectronic oscillator with an intra-loop Michelson interferometer.

Science.gov (United States)

Lee, Jehyun; Park, Sooyoung; Seo, Dae Han; Yim, Sin Hyuk; Yoon, Seokchan; Cho, D

2016-09-19

We report on measurement of small displacements with sub-nanometer precision using an optoelectronic oscillator (OEO) with an intra-loop Michelson interferometer. In comparison with conventional homodyne and heterodyne detection methods, where displacement appears as a power change or a phase shift, respectively, in the OEO detection, the displacement produces a shift in the oscillation frequency. In comparison with typical OEO sensors, where the frequency shift is proportional to the OEO oscillation frequency in radio-frequency domain, the frequency shift in our method with an intra-loop interferometer is proportional to an optical frequency. We constructed a hybrid apparatus and compared characteristics of the OEO and heterodyne detection methods.

The D18 diffractometer for neutron interferometry at the I.L.L

International Nuclear Information System (INIS)

Bauspiess, W.

1978-01-01

Three things are needed for neutron interferometry: an interferometer (a crystal in the case of Bragg diffraction interferometry), a neutron source, and a device to select and handle the neutrons that shall be used. It is this last technical aspect of neutron interferometry which is discussed in the paper, using as an example the new diffractometer for neutron interferometry that is being built at the I.L.L. Results of performance tests are not presently available but its characteristics are visible from the design. The experimental figures given in the paper refer to experiments performed with the prototype machine, or are extrapolated from said experiments

First Measurements of High Frequency Cross-Spectra from a Pair of Large Michelson Interferometers

Energy Technology Data Exchange (ETDEWEB)

Chou, Aaron S.; Gustafson, Richard; Hogan, Craig; Kamai, Brittany; Kwon, Ohkyung; Lanza, Robert; McCuller, Lee; Meyer, Stephan S.; Richardson, Jonathan; Stoughton, Chris; Tomlin, Raymond; Waldman, Samuel; Weiss, Rainer

2016-09-01

Measurements are reported of high frequency cross-spectra of signals from the Fermilab Holometer, a pair of co-located 39 m, high power Michelson interferometers. The instrument obtains differential position sensitivity to cross-correlated signals far exceeding any previous measurement in a broad frequency band extending to the 3.8 MHz inverse light crossing time of the apparatus. A model of universal exotic spatial shear correlations that matches the Planck scale holographic information bound of space-time position states is excluded to 4.6{\\sigma} significance.

Optimization of Materials and Interfaces for Spintronic Devices

Science.gov (United States)

Clark, Billy

In recent years' Spintronic devices have drawn a significant amount of research attention. This interest comes in large part from their ability to enable interesting and new technology such as Spin Torque Transfer Random Access Memory or improve existing technology such as High Signal Read Heads for Hard Disk Drives. For the former we worked on optimizing and improving magnetic tunnel junctions by optimizing their thermal stability by using Ta insertion layers in the free layer. We further tried to simplify the design of the MTJ stack by attempting to replace the Co/Pd multilayer with CoPd alloy. In this dissertation, we detail its development and examine the switching characteristics. Lastly we look at a highly spin polarized material, Fe2MnGe, for optimizing Hard Drive Disk read heads.

From master slave interferometry to complex master slave interferometry: theoretical work

Science.gov (United States)

Rivet, Sylvain; Bradu, Adrian; Maria, Michael; Feuchter, Thomas; Leick, Lasse; Podoleanu, Adrian

2018-03-01

A general theoretical framework is described to obtain the advantages and the drawbacks of two novel Fourier Domain Optical Coherence Tomography (OCT) methods denoted as Master/Slave Interferometry (MSI) and its extension denoted as Complex Master/Slave Interferometry (CMSI). Instead of linearizing the digital data representing the channeled spectrum before a Fourier transform can be applied to it (as in OCT standard methods), channeled spectrum is decomposed on the basis of local oscillations. This replaces the need for linearization, generally time consuming, before any calculation of the depth profile in the range of interest. In this model two functions, g and h, are introduced. The function g describes the modulation chirp of the channeled spectrum signal due to nonlinearities in the decoding process from wavenumber to time. The function h describes the dispersion in the interferometer. The utilization of these two functions brings two major improvements to previous implementations of the MSI method. The paper details the steps to obtain the functions g and h, and represents the CMSI in a matrix formulation that enables to implement easily this method in LabVIEW by using parallel programming with multi-cores.

Refractive index sensor based on an abrupt taper Michelson interferometer in a single-mode fiber.

Science.gov (United States)

Tian, Zhaobing; Yam, Scott S-H; Loock, Hans-Peter

2008-05-15

A simple refractive index sensor based on a Michelson interferometer in a single-mode fiber is constructed and demonstrated. The sensor consists of a single symmetrically abrupt taper region in a short piece of single-mode fiber that is terminated by approximately 500 nm thick gold coating. The sensitivity of the new sensor is similar to that of a long-period-grating-type sensor, and its ease of fabrication offers a low-cost alternative to current sensing applications.

A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments

Energy Technology Data Exchange (ETDEWEB)

Feister, S., E-mail: feister.7@osu.edu; Orban, C. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Nees, J. A. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Center for Ultra-Fast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Morrison, J. T. [Fellow, National Research Council, Washington, D.C. 20001 (United States); Frische, K. D. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Chowdhury, E. A. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Intense Energy Solutions, LLC., Plain City, Ohio 43064 (United States); Roquemore, W. M. [Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

2014-11-15

Ultra-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements

Correction of detector nonlinearity for the balloonborne Michelson Interferometer for Passive Atmospheric Sounding.

Science.gov (United States)

Kleinert, Anne

2006-01-20

The detectors used in the cryogenic limb-emission sounder MIPAS-B2 (Michelson Interferometer for Passive Atmospheric Sounding) show a nonlinear response, which leads to radiometric errors in the calibrated spectra if the nonlinearity is not taken into account. In the case of emission measurements, the dominant error that arises from the nonlinearity is the changing detector responsivity as the incident photon load changes. The effect of the distortion of a single interferogram can be neglected. A method to characterize the variable responsivity and to correct for this effect is proposed. Furthermore, a detailed error estimation is presented.

Integrated Spintronic Platforms for Biomolecular Recognition Detection

Science.gov (United States)

Martins, V. C.; Cardoso, F. A.; Loureiro, J.; Mercier, M.; Germano, J.; Cardoso, S.; Ferreira, R.; Fonseca, L. P.; Sousa, L.; Piedade, M. S.; Freitas, P. P.

2008-06-01

This paper covers recent developments in magnetoresistive based biochip platforms fabricated at INESC-MN, and their application to the detection and quantification of pathogenic waterborn microorganisms in water samples for human consumption. Such platforms are intended to give response to the increasing concern related to microbial contaminated water sources. The presented results concern the development of biological active DNA chips and protein chips and the demonstration of the detection capability of the present platforms. Two platforms are described, one including spintronic sensors only (spin-valve based or magnetic tunnel junction based), and the other, a fully scalable platform where each probe site consists of a MTJ in series with a thin film diode (TFD). Two microfluidic systems are described, for cell separation and concentration, and finally, the read out and control integrated electronics are described, allowing the realization of bioassays with a portable point of care unit. The present platforms already allow the detection of complementary biomolecular target recognition with 1 pM concentration.

High-contrast Nulling Interferometry Techniques Project

Data.gov (United States)

National Aeronautics and Space Administration — "We are developing rotating-baseline nulling-interferometry techniques and algorithms on the single-aperture Hale and Keck telescopes at near-infrared wavelengths,...

Global astrometry with the space interferometry mission

Science.gov (United States)

Boden, A.; Unwin, S.; Shao, M.

1997-01-01

The prospects for global astrometric measurements with the space interferometry mission (SIM) are discussed. The SIM mission will perform four microarcsec astrometric measurements on objects as faint as 20 mag using the optical interferometry technique with a 10 m baseline. The SIM satellite will perform narrow angle astrometry and global astrometry by means of an astrometric grid. The sensitivities of the SIM global astrometric performance and the grid accuracy versus instrumental parameters and sky coverage schemes are reported on. The problems in finding suitable astrometric grid objects to support microarcsec astrometry, and related ground-based observation programs are discussed.

Interferometry correlations in central p+Pb collisions

Science.gov (United States)

Bożek, Piotr; Bysiak, Sebastian

2018-01-01

We present results on interferometry correlations for pions emitted in central p+Pb collisions at √{s_{NN}}=5.02 TeV in a 3+1-dimensional viscous hydrodynamic model with initial conditions from the Glauber Monte Carlo model. The correlation function is calculated as a function of the pion pair rapidity. The extracted interferometry radii show a weak rapidity dependence, reflecting the lack of boost invariance of the pion distribution. A cross term between the out and long directions is found to be nonzero. The results obtained in the hydrodynamic model are in fair agreement with recent data of the ATLAS Collaboration.

Analytic approximations for inside-outside interferometry

Energy Technology Data Exchange (ETDEWEB)

Padula, S.S.; Gyulassy, M. (Lawrence Berkeley Lab., CA (USA). Nuclear Science Div.)

1990-07-30

Analytical expressions for pion interferometry are derived illustrating the competing effects of various non-ideal aspects of inside-outside cascade dynamics at energies {proportional to}200 AGeV. (orig.).

A publication database for optical long baseline interferometry

Science.gov (United States)

Malbet, Fabien; Mella, Guillaume; Lawson, Peter; Taillifet, Esther; Lafrasse, Sylvain

2010-07-01

Optical long baseline interferometry is a technique that has generated almost 850 refereed papers to date. The targets span a large variety of objects from planetary systems to extragalactic studies and all branches of stellar physics. We have created a database hosted by the JMMC and connected to the Optical Long Baseline Interferometry Newsletter (OLBIN) web site using MySQL and a collection of XML or PHP scripts in order to store and classify these publications. Each entry is defined by its ADS bibcode, includes basic ADS informations and metadata. The metadata are specified by tags sorted in categories: interferometric facilities, instrumentation, wavelength of operation, spectral resolution, type of measurement, target type, and paper category, for example. The whole OLBIN publication list has been processed and we present how the database is organized and can be accessed. We use this tool to generate statistical plots of interest for the community in optical long baseline interferometry.

A reliable, compact and low-cost Michelson wavemeter for laser wavelength measurement

International Nuclear Information System (INIS)

Fox, P.J.; Scholten, R.E.; Walkiewicz, M.R.; Drullinger, R.E.

1998-01-01

We describe the construction and operation of a simple, compact and cost effective Michelson wavemeter with picometer accuracy. The low cost of the device means that it can form the basis of an undergraduate laboratory experiment, yet it is sufficiently reliable and accurate that it has become an important tool in our research laboratory, where it is regularly used to tune lasers to atomic transitions. The usefulness and accuracy of the wavemeter is demonstrated by tuning two separate extended cavity diode lasers to achieve two-step excitation of the Rb 5 2 D state, observed by detecting 420 nm blue fluorescence from the 5 2 D → 6 2 P → 5 2 S decay path. (authors)

Optical stream-cipher-like system for image encryption based on Michelson interferometer.

Science.gov (United States)

Yang, Bing; Liu, Zhengjun; Wang, Bo; Zhang, Yan; Liu, Shutian

2011-01-31

A novel optical image encryption scheme based on interference is proposed. The original image is digitally encoded into one phase-only mask by employing an improved Gerchberg-Saxton phase retrieval algorithm together with another predefined random phase mask which serves as the encryption key. The decryption process can be implemented optically based on Michelson interferometer by using the same key. The scheme can be regarded as a stream-cipher-like encryption system, the encryption and decryption keys are the same, however the operations are different. The position coordinates and light wavelength can also be used as additional keys during the decryption. Numerical simulations have demonstrated the validity and robustness of the proposed method.

Atom Interferometry for Fundamental Physics and Gravity Measurements in Space

Science.gov (United States)

Kohel, James M.

2012-01-01

Laser-cooled atoms are used as freefall test masses. The gravitational acceleration on atoms is measured by atom-wave interferometry. The fundamental concept behind atom interferometry is the quantum mechanical particle-wave duality. One can exploit the wave-like nature of atoms to construct an atom interferometer based on matter waves analogous to laser interferometers.

Dynamical properties of three terminal magnetic tunnel junctions: Spintronics meets spin-orbitronics

Energy Technology Data Exchange (ETDEWEB)

Tomasello, R. [Department of Computer Science, Modeling, Electronics and System Science, University of Calabria, Rende (CS) (Italy); Carpentieri, M., E-mail: m.carpentieri@poliba.it [Department of Electrical and Information Engineering, Politecnico of Bari, via E. Orabona 4, I-70125 Bari (Italy); Finocchio, G. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, I-98166 Messina (Italy)

2013-12-16

This Letter introduces a micromagnetic model able to characterize the magnetization dynamics in three terminal magnetic tunnel junctions, where the effects of spin-transfer torque and spin-orbit torque are taken into account. Our results predict that the possibility to separate electrically those two torque sources is very promising from a technological point of view for both next generation of nanoscale spintronic oscillators and microwave detectors. A scalable synchronization scheme based on the parallel connection of those three terminal devices is also proposed.

Dynamical properties of three terminal magnetic tunnel junctions: Spintronics meets spin-orbitronics

International Nuclear Information System (INIS)

Tomasello, R.; Carpentieri, M.; Finocchio, G.

2013-01-01

This Letter introduces a micromagnetic model able to characterize the magnetization dynamics in three terminal magnetic tunnel junctions, where the effects of spin-transfer torque and spin-orbit torque are taken into account. Our results predict that the possibility to separate electrically those two torque sources is very promising from a technological point of view for both next generation of nanoscale spintronic oscillators and microwave detectors. A scalable synchronization scheme based on the parallel connection of those three terminal devices is also proposed

Resolving power test of 2-D K{sup +} K{sup +} interferometry

Energy Technology Data Exchange (ETDEWEB)

Padula, Sandra S.; Roldao, Christiane G. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil)

1999-07-01

Adopting a procedure previously proposed to quantitatively study pion interferometry {sup 1} , an equivalent 2-D X{sup 2} analysis was performed to test the resolving power of that method when applied to less favorable conditions, when no significant contribution from long lived resonances is expected, as in kaon interferometry. For that purpose, use is made of the preliminary E859 K{sup +}K{sup +} interferometry data from Si+Au collisions at 14.6 A GeV/c. Less sensitivity is achieved in the present case, although it is shown that it is still possible to distinguish two distinct decoupling geometries. (author)

Secondary wavelength stabilization of unbalanced Michelson interferometers for the generation of low-jitter pulse trains.

Science.gov (United States)

Shalloo, R J; Corner, L

2016-09-01

We present a double unbalanced Michelson interferometer producing up to four output pulses from a single input pulse. The interferometer is stabilized with the Hänsch-Couillaud method using an auxiliary low power continuous wave laser injected into the interferometer, allowing the stabilization of the temporal jitter of the output pulses to 0.02 fs. Such stabilized pulse trains would be suitable for driving multi-pulse laser wakefield accelerators, and the technique could be extended to include amplification in the arms of the interferometer.

Improvement of input power dynamic range for 20 Gbit/s optical WDM switch nodes using an integrated Michelson wavelength converter

DEFF Research Database (Denmark)

Danielsen, Søren Lykke; Hansen, Peter Bukhave; Jørgensen, Carsten

1997-01-01

be improved compared to switch blocks without IWCs. This is especially important at high bit rates where the cascadability of the SOA gates decreases. Here, more than 15 dB improvement of the input power dynamic range is achieved at 20 Gbit/s using a high-speed Michelson interferometer wavelength converter...

Quantum mechanical noise in coherent-state and squeezed-state Michelson interferometers

International Nuclear Information System (INIS)

Assaf, Ohad; Ben-Aryeh, Yacob

2002-01-01

In the present study we extend and generalize previous results for coherent-state and squeezed-state Michelson interferometer quantum mechanical uncertainties (or fluctuations), which are commonly referred to as 'quantum noise'. The calculation of photon counting (PC) fluctuations in the squeezed-state interferometer is extended to fourth-order correlation functions used as the measured signal. We also generalize a 'unified model' for treating both PC and radiation pressure fluctuations in the coherent-state interferometer, by using mathematical methods which apply to Kerr-type interactions. The results are more general than those reported previously in two ways. First, we obtain exact expressions, which lead to previous results under certain approximations. Second, we deal with cases in which the responses of the two mirrors to radiation pressure are not equal

Interferometry correlations in central p+Pb collisions

Energy Technology Data Exchange (ETDEWEB)

Bozek, Piotr; Bysiak, Sebastian [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow (Poland)

2018-01-15

We present results on interferometry correlations for pions emitted in central p+Pb collisions at √(s{sub NN}) = 5.02 TeV in a 3 + 1-dimensional viscous hydrodynamic model with initial conditions from the Glauber Monte Carlo model. The correlation function is calculated as a function of the pion pair rapidity. The extracted interferometry radii show a weak rapidity dependence, reflecting the lack of boost invariance of the pion distribution. A cross term between the out and long directions is found to be nonzero. The results obtained in the hydrodynamic model are in fair agreement with recent data of the ATLAS Collaboration. (orig.)

X-ray Talbot interferometry with capillary plates

International Nuclear Information System (INIS)

Momose, Atsushi; Kawamoto, Shinya

2006-01-01

An X-ray Talbot interferometer consisting of two capillary plates, which were used as X-ray amplitude gratings, was evaluated for X-ray phase imaging. A theoretical aspect of capillary X-ray Talbot interferometry is presented with a preliminary operation result using synchrotron radiation. A two-dimensional X-ray Talbot effect, or self-imaging effect, which was the basis of Talbot interferometry, was observed with the capillary plate, and moire images formed by the X-ray Talbot interferometer exhibited contrasts corresponding to the differential phase shift caused by phase objects placed in front of the interferometer. Finally, the possibility of quantitative phase measurement with a fringe scanning technique is discussed. (author)

Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling.

Science.gov (United States)

Thüring, André; Gräf, Christian; Vahlbruch, Henning; Mehmet, Moritz; Danzmann, Karsten; Schnabel, Roman

2009-03-15

Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically coupled cavities and efficiently enhances the sensitivity of an interferometer at a dedicated signal frequency. We report on what we believe to be the first experimental realization of a TSR Michelson interferometer and also its broadband enhancement by squeezed light injection. The complete setup was stably locked, and a broadband quantum noise reduction of the interferometers shot noise by a factor of up to 4 dB was demonstrated. The system was characterized by measuring its quantum noise spectra for several tunings of the TSR cavities. We found good agreement between the experimental results and numerical simulations.

Prospects of asymmetrically H-terminated zigzag germanene nanoribbons for spintronic application

Energy Technology Data Exchange (ETDEWEB)

Sharma, Varun, E-mail: varun@iiitm.ac.in [Nanomaterials Research Group, ABV-Indian Institute of Information Technology and Management (IIITM), Gwalior 474015 (India); Srivastava, Pankaj [Nanomaterials Research Group, ABV-Indian Institute of Information Technology and Management (IIITM), Gwalior 474015 (India); Jaiswal, Neeraj K. [Discipline of Physics, Indian Institute of Information Technology, Design & Manufacturing, Jabalpur, Dumna Airport Road, Jabalpur 482005 (India)

2017-02-28

Highlights: • Asymmetric hydrogen termination of Zigzag Germanene Nanoribbons (ZGeNR) is presented with their plausible spintronic device application. • It is revealed that asymmetric terminations are energetically more favourable compared to symmetric terminations. • The magnetic moment analysis depicts that asymmetric ZGeNR have a magnetic ground state with a preferred ferromagnetic (FM) coupling. • Presented doped asymmetric ZGeNR exhibits a half-metallic character which makes them qualify for spin-filtering device. - Abstract: First-principles investigations have been performed to explore the spin based electronic and transport properties of asymmetrically H-terminated zigzag germanene nanoribbons (2H−H ZGeNR). Investigations reveal a significant formation energy difference (ΔE{sub F} = E{sub F(2H-H)} − E{sub F(H-H)} ∼ −0.49 eV), highlighting more energetic stability for asymmetric edge termination compared to symmetric edge termination, irrespective of the ribbon width. Further, magnetic moment analysis and total energy calculations were performed to unveil that these structures have a magnetic ground state with preferred ferromagnetic (FM) coupling. The calculated E-k structures project a unique bipolar semiconducting behaviour for 2H−H ZGeNR which is contrast to H-terminated ZGeNR. Half-metallic transformation has also been revealed via suitable p-type or n-type doping for these structures. Finally, transport calculations were performed to highlight the selective contributions of spin-down (spin-up) electrons in the I–V characteristics of the doped 2H−H ZGeNR, suggesting their vitality for spintronic device applications.

Interferometry of high energy nuclear collisions

International Nuclear Information System (INIS)

Padula, S.S.

1990-01-01

The interferometry is used for determining large space time dimensions of the Quark Gluon Plasma formed in high energy nuclear collisions or in high multiplicity fluctuations in p-barp collisions. (M.C.K.)

Electromagnetic interferometry in wavenumber and space domains in a layered earth

NARCIS (Netherlands)

Hunziker, J.W.; Slob, E.C.; Fan, Y.; Snieder, R.; Wapenaar, C.P.A.

2013-01-01

With interferometry applied to controlled-source electromagnetic data, the direct field and the airwave and all other effects related to the air-water interface can be suppressed in a data-driven way. Interferometry allows for retreival of the scattered field Green’s function of the subsurface or,

Fundamental physics research and neutron interferometry

Energy Technology Data Exchange (ETDEWEB)

Ioffe, A. [Hahn-Meitner-Institut Berlin GmbH (Germany)

1996-08-01

The possibility of the use of an extremely sensitive neutron interferometry technique for the study of electromagnetic structure of the neutron and the parity non-conservative effects in neutron spin rotation is discussed. (author)

Complete positivity and neutron interferometry

International Nuclear Information System (INIS)

Benatti, F.; Floreanini, R.

1999-01-01

We analyze the dynamics of neutron beams in interferometry experiments using quantum dynamical semigroups. We show that these experiments could provide stringent limits on the non-standard, dissipative terms appearing in the extended evolution equations. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Monopole and topological electron dynamics in adiabatic spintronic and graphene systems

International Nuclear Information System (INIS)

Tan, S.G.; Jalil, M.B.A.; Fujita, T.

2010-01-01

A unified theoretical treatment is presented to describe the physics of electron dynamics in semiconductor and graphene systems. Electron spin's fast alignment with the Zeeman magnetic field (physical or effective) is treated as a form of adiabatic spin evolution which necessarily generates a monopole in magnetic space. One could transform this monopole into the physical and intuitive topological magnetic fields in the useful momentum (K) or real spaces (R). The physics of electron dynamics related to spin Hall, torque, oscillations and other technologically useful spinor effects can be inferred from the topological magnetic fields in spintronic, graphene and other SU(2) systems.

Onboard calibration and monitoring for the SWIFT instrument

International Nuclear Information System (INIS)

Rahnama, P; McDade, I; Shepherd, G; Gault, W

2012-01-01

The SWIFT (Stratospheric Wind Interferometer for Transport studies) instrument is a proposed space-based field-widened Doppler Michelson interferometer designed to measure stratospheric winds and ozone densities using a passive optical technique called Doppler Michelson imaging interferometry. The onboard calibration and monitoring procedures for the SWIFT instrument are described in this paper. Sample results of the simulations of onboard calibration measurements are presented and discussed. This paper also discusses the results of the derivation of the calibrations and monitoring requirements for the SWIFT instrument. SWIFT's measurement technique and viewing geometry are briefly described. The reference phase calibration and filter monitoring for the SWIFT instrument are two of the main critical design issues. In this paper it is shown that in order to meet SWIFT's science requirements, Michelson interferometer optical path difference monitoring corresponding to a phase calibration accuracy of ∼10 −3 radians, filter passband monitoring corresponding to phase accuracy of ∼5 × 10 −3 radians and a thermal stability of 10 −3 K s −1 are required. (paper)

A review of recent work in sub-nanometre displacement measurement using optical and X-ray interferometry.

Science.gov (United States)

Peggs, G N; Yacoot, A

2002-05-15

This paper reviews recent work in the field of displacement measurement using optical and X-ray interferometry at the sub-nanometre level of accuracy. The major sources of uncertainty in optical interferometry are discussed and a selection of recent designs of ultra-precise, optical-interferometer-based, displacement measuring transducers presented. The use of X-ray interferometry and its combination with optical interferometry is discussed.

Ghost reflections of Gaussian beams in anamorphic optical systems with an application to Michelson interferometer.

Science.gov (United States)

Abd El-Maksoud, Rania H

2016-02-20

In this paper, a methodology is developed to model and analyze the effect of undesired (ghost) reflections of Gaussian beams that are produced by anamorphic optical systems. The superposition of these beams with the nominal beam modulates the nominal power distribution at the recording plane. This modulation may cause contrast reduction, veiling parts of the nominal image, and/or the formation of spurious interference fringes. The developed methodology is based on synthesizing the beam optical paths into nominal and ghost optical beam paths. Similar to the nominal beam, we present the concept that each ghost beam is characterized by a beam size, wavefront radius of curvature, and Gouy phase in the paraxial regime. The nominal and ghost beams are sequentially traced through the system and formulas for estimating the electric field magnitude and phase of each ghost beam at the recording plane are presented. The effective electric field is the addition of the individual nominal and ghost electric fields. Formulas for estimating Gouy phase, the shape of the interference fringes, and the central interference order are introduced. As an application, the theory of the formation of the interference fringes by Michelson interferometer is presented. This theory takes into consideration the ghost reflections that are formed by the beam splitter. To illustrate the theory and to show its wide applicability, simulation examples that include a Mangin mirror, a Michelson interferometer, and a black box optical system are provided.

Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Monolithic Interferometer Design and Test

Science.gov (United States)

Harlander, John M.; Englert, Christoph R.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Zastera, Vaz; Bach, Bernhard W.; Mende, Stephen B.

2017-10-01

The design and laboratory tests of the interferometers for the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument which measures thermospheric wind and temperature for the NASA-sponsored Ionospheric Connection (ICON) Explorer mission are described. The monolithic interferometers use the Doppler Asymmetric Spatial Heterodyne (DASH) Spectroscopy technique for wind measurements and a multi-element photometer approach to measure thermospheric temperatures. The DASH technique and overall optical design of the MIGHTI instrument are described in an overview followed by details on the design, element fabrication, assembly, laboratory tests and thermal control of the interferometers that are the heart of MIGHTI.

High-temperature sensor based on an abrupt-taper Michelson interferometer in single-mode fiber.

Science.gov (United States)

Xu, Le; Jiang, Lan; Wang, Sumei; Li, Benye; Lu, Yongfeng

2013-04-01

This study proposes a high-temperature sensor based on an abrupt fiber-taper Michelson interferometer (FTMI) in single-mode fiber fabricated by a fiber-taper machine and electric-arc discharge. The proposed FTMI is applied to measure temperature and refractive index (RI). A high temperature sensitivity of 118.6 pm/°C is obtained in the temperature range of 500°C-800°C. The wavelength variation is only -0.335 nm for the maximum attenuation peak, with the external RI changed from 1.333 to 1.3902, which is desirable for high-temperature sensing to eliminate the cross sensitivity to RI.

From Spintronics to CFD/ContractForDifferences

Science.gov (United States)

Maksoed, W. H.

2015-11-01

Involve the CFD/Computational Fluid Dynamics & HCCI/Homogeneous Charge Compression Ignition - Marcine Frackowiak, dissertation, 2009, for CFD/Contract For Differences accompanied by ``One Man's Crusade to Exonerate Hydrogen for Hindenburg Disaster'' of Addison BAIN, APS News, v. 9, n.7 (July 2000) concludes ``ignition of the blaze'' are responsible to those May, 1937 Accidents. Spintronics their selves include active control & manipulation of spin degree of freedom ever denotes: the nano-obelisk of scanning electron microscopy of galliumnitride/GaN nanostructures-Yong-Hon Cho et al.:``Novel Photonic Device using core-shell nanostructures'', SPIE-newsroom,10.1117/2.1201503.005864. Herewith commercial activated carbon/C can be imaged directly using abberation-corrected transmission electron microscopy[PJF Harris et al.: ``Imaging the Atomic Structures of activated C'', J. Phys. Condens. Matt, 20 (2008) in fig b & c- images networks of hexagonal rings can be clearly be seen depicts equal etchings of 340 px Akhenaten, Nefertiti & their childrens. Incredible acknowledgments to Minister of Education & Culture RI 1998-1999 HE. Mr. Prof. Ir. WIRANTO ARISMUNANDAR, MSME.

ESPINTRÓNICA, LA ELECTRONICA DEL ESPÍN SPINTRONICS, SPIN ELECTRONICS

KAUST Repository

Monteblanco, Elmer

2017-03-14

Current technology seeks to develop nanoscale devices capable of storing and processing information. These devices would be difficult to make in the area of electronics, which is based on the manipulation of electric charge. However, thanks to advances in experimental and theoretical physics in the field of condensed matter, these devices are already a reality, belonging to the field of what we now call spintronics, which bases its functionality on the control of the electron’s spin, a property that can only be conceived at the quantum level. In this article we review this new perspective, describing giant- and tunneling- magnetoresistance, the spin transfer torque, and their applications such as MRAM memories, nano-oscillators and lateral spin valves.

ESPINTRÓNICA, LA ELECTRONICA DEL ESPÍN SPINTRONICS, SPIN ELECTRONICS

KAUST Repository

Monteblanco, Elmer; Ortiz Pauyac, Christian; Savero, Williams; RojasSanchez, J. Carlos; Schuhl, A.

2017-01-01

Current technology seeks to develop nanoscale devices capable of storing and processing information. These devices would be difficult to make in the area of electronics, which is based on the manipulation of electric charge. However, thanks to advances in experimental and theoretical physics in the field of condensed matter, these devices are already a reality, belonging to the field of what we now call spintronics, which bases its functionality on the control of the electron’s spin, a property that can only be conceived at the quantum level. In this article we review this new perspective, describing giant- and tunneling- magnetoresistance, the spin transfer torque, and their applications such as MRAM memories, nano-oscillators and lateral spin valves.

Cr-doped III-V nitrides: Potential candidates for spintronics

KAUST Repository

Amin, Bin

2011-02-19

Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

Cr-doped III-V nitrides: Potential candidates for spintronics

KAUST Repository

Amin, Bin; Arif, Suneela K.; Ahmad, Iftikhar; Maqbool, Muhammad; Ahmad, Roshan; Goumri-Said, Souraya; Prisbrey, Keith A.

2011-01-01

Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

Manipulating spin in organic spintronics : probing the interplay between the electronic and nuclear spins in organic semiconductors

NARCIS (Netherlands)

Bobbert, P.A.

2014-01-01

The growing interest in spin manipulation in the field of spin electronics, or "spintronics," is due to the wealth of exciting possibilities that it offers in areas of magnetic sensing, new types of information storage, low-power electronics, and quantum information processing. Nuclear spin

Space Interferometry Mission Instrument Mechanical Layout

Science.gov (United States)

Aaron, K.; Stubbs, D.; Kroening, K.

2000-01-01

The Space Interferometry Mission, planned for launch in 2006, will measure the positions of celestial objects to an unprecedented accuracy of 4x10 to the power of negative six arc (about 1 billionth of a degree).

Infrared spectroscopy with a balloon borne Michelson interferometer. Pt. 2

International Nuclear Information System (INIS)

Moorwood, A.F.M.; Salinari, P.; Furniss, I.; Jennings, R.E.; King, K.J.

1980-01-01

Observations of the [O III] ionic fine structure lines at 52 μm and 88 μm, made at a resolution of 0.05 cm -1 with a balloon borne telescope and Michelson interferometer, are presented for the H II regions W 51, G33.6-0.2. M 17 S, M 17 N, NGC 6357, and NGC 6334. This is the first time that both [O III] lines have been measured simultaneously. Values for the electron density deduced from the line ratios are found to agree with the radio data, while the O ++ abundances indicate a lower excitation than expected in many cases. The [O I] line at 63 μm was also detected in NGC 6357. In addition, we report the first detection of the [N III] line at 57 μm which was observed from both sources in M 17 and gives the abundance ratio N/O = 0.13. This line was also marginally detected on W 51. (orig.)

Neutron interferometry lessons in experimental quantum mechanics, wave-particle duality, and entanglement

CERN Document Server

Rauch, Helmut

2015-01-01

The quantum interference of de Broglie matter waves is probably one of the most startling and fundamental aspects of quantum mechanics. It continues to tax our imaginations and leads us to new experimental windows on nature. Quantum interference phenomena are vividly displayed in the wide assembly of neutron interferometry experiments, which have been carried out since the first demonstration of a perfect silicon crystal interferometer in 1974. Since the neutron experiences all four fundamental forces of nature (strong, weak, electromagnetic, and gravitational), interferometry with neutrons provides a fertile testing ground for theory and precision measurements. Many Gedanken experiments of quantum mechanics have become real due to neutron interferometry. Quantum mechanics is a part of physics where experiment and theory are inseparably intertwined. This general theme permeates the second edition of this book. It discusses more than 40 neutron interferometry experiments along with their theoretical motivation...

Kinetic Titration Series with Biolayer Interferometry

Science.gov (United States)

Frenzel, Daniel; Willbold, Dieter

2014-01-01

Biolayer interferometry is a method to analyze protein interactions in real-time. In this study, we illustrate the usefulness to quantitatively analyze high affinity protein ligand interactions employing a kinetic titration series for characterizing the interactions between two pairs of interaction patterns, in particular immunoglobulin G and protein G B1 as well as scFv IC16 and amyloid beta (1–42). Kinetic titration series are commonly used in surface plasmon resonance and involve sequential injections of analyte over a desired concentration range on a single ligand coated sensor chip without waiting for complete dissociation between the injections. We show that applying this method to biolayer interferometry is straightforward and i) circumvents problems in data evaluation caused by unavoidable sensor differences, ii) saves resources and iii) increases throughput if screening a multitude of different analyte/ligand combinations. PMID:25229647

Threshold secret sharing scheme based on phase-shifting interferometry.

Science.gov (United States)

Deng, Xiaopeng; Shi, Zhengang; Wen, Wei

2016-11-01

We propose a new method for secret image sharing with the (3,N) threshold scheme based on phase-shifting interferometry. The secret image, which is multiplied with an encryption key in advance, is first encrypted by using Fourier transformation. Then, the encoded image is shared into N shadow images based on the recording principle of phase-shifting interferometry. Based on the reconstruction principle of phase-shifting interferometry, any three or more shadow images can retrieve the secret image, while any two or fewer shadow images cannot obtain any information of the secret image. Thus, a (3,N) threshold secret sharing scheme can be implemented. Compared with our previously reported method, the algorithm of this paper is suited for not only a binary image but also a gray-scale image. Moreover, the proposed algorithm can obtain a larger threshold value t. Simulation results are presented to demonstrate the feasibility of the proposed method.

Deghosting, Demultiple, and Deblurring in Controlled-Source Seismic Interferometry

Directory of Open Access Journals (Sweden)

Joost van der Neut

2011-01-01

Full Text Available With controlled-source seismic interferometry we aim to redatum sources to downhole receiver locations without requiring a velocity model. Interferometry is generally based on a source integral over cross-correlation (CC pairs of full, perturbed (time-gated, or decomposed wavefields. We provide an overview of ghosts, multiples, and spatial blurring effects that can occur for different types of interferometry. We show that replacing cross-correlation by multidimensional deconvolution (MDD can deghost, demultiple, and deblur retrieved data. We derive and analyze MDD for perturbed and decomposed wavefields. An interferometric point spread function (PSF is introduced that can be obtained directly from downhole data. Ghosts, multiples, and blurring effects that may populate the retrieved gathers can be locally diagnosed with the PSF. MDD of perturbed fields can remove ghosts and deblur retrieved data, but it leaves particular multiples in place. To remove all overburden-related effects, MDD of decomposed fields should be applied.

Practical optical interferometry imaging at visible and infrared wavelengths

CERN Document Server

Buscher, David F

2015-01-01

Optical interferometry is a powerful technique to make images on angular scales hundreds of times smaller than is possible with the largest telescopes. This concise guide provides an introduction to the technique for graduate students and researchers who want to make interferometric observations and acts as a reference for technologists building new instruments. Starting from the principles of interference, the author covers the core concepts of interferometry, showing how the effects of the Earth's atmosphere can be overcome using closure phase, and the complete process of making an observation, from planning to image reconstruction. This rigorous approach emphasizes the use of rules-of-thumb for important parameters such as the signal-to-noise ratios, requirements for sampling the Fourier plane and predicting image quality. The handbook is supported by web resources, including the Python source code used to make many of the graphs, as well as an interferometry simulation framework, available at www.cambridg...

3D super-virtual refraction interferometry

KAUST Repository

Lu, Kai; AlTheyab, Abdullah; Schuster, Gerard T.

2014-01-01

Super-virtual refraction interferometry enhances the signal-to-noise ratio of far-offset refractions. However, when applied to 3D cases, traditional 2D SVI suffers because the stationary positions of the source-receiver pairs might be any place

Beam-modulation methods in quantitative and flow-visualization holographic interferometry

Science.gov (United States)

Decker, Arthur J.

1986-01-01

Heterodyne holographic interferometry and time-average holography with a frequency shifted reference beam are discussed. Both methods will be used for the measurement and visualization of internal transonic flows where the target facility is a flutter cascade. The background and experimental requirements for both methods are reviewed. Measurements using heterodyne holographic interferometry are presented. The performance of the laser required for time-average holography of time-varying transonic flows is discussed.

Noise Suppression on the Tunable Laser for Precise Cavity Length Displacement Measurement

Czech Academy of Sciences Publication Activity Database

Šmíd, Radek; Čížek, Martin; Mikel, Břetislav; Hrabina, Jan; Lazar, Josef; Číp, Ondřej

2016-01-01

Roč. 16, č. 9 (2016), 1428:1-11 ISSN 1424-8220 R&D Projects: GA ČR(CZ) GPP102/12/P962; GA ČR GB14-36681G; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Fabry-Perot cavity * unbalance Michelson interferometer * noise suppression * heterodyne interferometry * displacement measurement Subject RIV: BH - Optics, Masers, Laser s Impact factor: 2.677, year: 2016

LSMO - growing opportunities by PLD and applications in spintronics

Energy Technology Data Exchange (ETDEWEB)

Cesaria, M; Caricato, A P; Maruccio, G; Martino, M, E-mail: maura.cesaria@le.infn.it [Physics Department, University of Salento, Via Arnesano, 73100, Lecce (Italy)

2011-04-01

Ferromagnetic materials exhibiting at room temperature combination of good conductivity, magnetic and opto-electronic properties are needed for the development of functional spin-devices. Mixed-valence LSMO is an optimal source of fully spin-polarized carriers and shows a rich physics of magnetic phases and transport mechanisms. Many factors, such as growth temperature, oxygen stoichiometry, temperature-dependent oxygen desorption rate, structural matching between the growing film and substrate, film thickness, and defects, influence the LSMO properties. Stabilization of ferromagnetic and conductive behaviours is linked to structural order. Therefore a growth approach allowing congruent deposition of complex materials under controlled, reproducible and tunable conditions is strongly needed. In this respect pulsed laser deposition reveals a well-suited choice. This review aims to give an overview on LSMO thin film properties, deposition and applications, especially in the emerging organic spintronics.

Time-Delay Interferometry

Directory of Open Access Journals (Sweden)

Massimo Tinto

2014-08-01

Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

O2 nightglow snapshots of the 1.27 μm emission at low latitudes on Mars with a static field-widened Michelson interferometer

Science.gov (United States)

Zhang, Rui; Ward, William E.; Zhang, Chunmin

2017-12-01

A static field-widened Michelson interferometer is designed to observe the atmospheric dynamics at low latitudes of Mars, targeting the 1.27 μm O2(a1Δg) nightglow, which has not yet been accurately detected due to its low intensity. To the best of our knowledge, this design is the first demonstration of implementing divided-mirror technique by refringent materials in a field-widened Michelson interferometer. Different optical path difference (OPD) in each quadrant is generated by four highly reflective pyramid-shaped prisms made of different refringent materials attached to each solid arm of Michelson interferometer. In this way four samples of interferogram are obtained simultaneously, from which the airglow volume emission rate, as well as the line-of-sight velocity and temperature of the air parcel where the emission forms can be derived in a single integration time. To achieve the best field-widening, compactness and thermal compensation, all possible combination of ten pieces of glasses were searched within the Sumita glass catalogue using a computer program and some interesting results are listed. The OPD used in this calculation concerns rays in the plane perpendicular to the sides of the prism only, other cases need further examination. This instrument's performance in measuring atmospheric dynamics is analysed, using the wind velocity uncertainty as primary criterion. Calculations show that it can measure the wind with an accuracy better than 2 m/s if the band volume emission rate of O2 nightglow is greater than 5 kph cm-3 s-1.

Novel Polarimetric SAR Interferometry Algorithms, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Polarimetric radar interferometry (PolInSAR) is a new SAR imaging mode that is rapidly becoming an important technique for bare earth topographic mapping, tree...

Beam-modulation methods in quantitative and flow visualization holographic interferometry

Science.gov (United States)

Decker, A.

1986-01-01

This report discusses heterodyne holographic interferometry and time-average holography with a frequency shifted reference beam. Both methods will be used for the measurement and visualization of internal transonic flows, where the target facility is a flutter cascade. The background and experimental requirements for both methods are reviewed. Measurements using heterodyne holographic interferometry are presented. The performance of the laser required for time-average holography of time-varying transonic flows is discussed.

Green's function representations for seismic interferometry

NARCIS (Netherlands)

Wapenaar, C.P.A.; Fokkema, J.T.

2006-01-01

The term seismic interferometry refers to the principle of generating new seismic responses by crosscorrelating seismic observations at different receiver locations. The first version of this principle was derived by Claerbout (1968), who showed that the reflection response of a horizontally layered

Optimization of a Michelson interferometer with a rotating retroreflector in opitcal design, spectral resolution, and optical throughput

International Nuclear Information System (INIS)

Haschberger, P.; Tank, V.

1993-01-01

A newly designed Michelson interferometer for Fourier spectroscopy utilizes a nutating retroreflector (cube corner mirror) to generate alterations in geometrical and optical paths. The practical optomechanical design of a Fourier-transform spectrometer incorporating a rotating retroreflector for path-length alteration is considered. (The instrument has been given the name MIROR, for Michelson Interferometer with a Rotating Retroreflector.) Two parameters of the instrument are essential: the maximum optical path difference, which yields the spectral resolution of the instrument, and the diameter of the transmitted beam, which determines the throughput and hence the achievable signal-to-noise ratio. The maximum allowable beam diameter is calculated as a function of the geometry and the orientation of the rotating retroreflector and the other optical components. The geometrical configuration and the orientation of all the optical components with respect to one another are also optimized for the maximum transmitted beam diameter when the required path difference is given. A principal investigation of different possible configurations of the optical components is presented. Then a quantitative optimization for an interferometer employing a retroreflector having a 5-in. (12.7-cm) aperture diameter requiring an optical path difference of more than 10 cm (spectral resolution better than 0.1 cm -1 ) is performed. Finally a simplified but enhanced design is described. 10 refs., 15 figs

Visualization and direct comparison of large displacements using difference holographic interferometry

International Nuclear Information System (INIS)

Necati Ecevit, F.; Aydin, R.

1994-01-01

The difference holographic interferometry provides the possibility of direct comparison of large displacements and deformations of two similar but different objects by application of a special kind of illumination. In this work, the principles of the difference holographic interferometry and the experimental results obtained by applying the single beam technique to large displacements is presented. (author). 10 refs, 4 figs

Application of deconvolution interferometry with both Hi-net and KiK-net data

Science.gov (United States)

Nakata, N.

2013-12-01

Application of deconvolution interferometry to wavefields observed by KiK-net, a strong-motion recording network in Japan, is useful for estimating wave velocities and S-wave splitting in the near surface. Using this technique, for example, Nakata and Snieder (2011, 2012) found changed in velocities caused by Tohoku-Oki earthquake in Japan. At the location of the borehole accelerometer of each KiK-net station, a velocity sensor is also installed as a part of a high-sensitivity seismograph network (Hi-net). I present a technique that uses both Hi-net and KiK-net records for computing deconvolution interferometry. The deconvolved waveform obtained from the combination of Hi-net and KiK-net data is similar to the waveform computed from KiK-net data only, which indicates that one can use Hi-net wavefields for deconvolution interferometry. Because Hi-net records have a high signal-to-noise ratio (S/N) and high dynamic resolution, the S/N and the quality of amplitude and phase of deconvolved waveforms can be improved with Hi-net data. These advantages are especially important for short-time moving-window seismic interferometry and deconvolution interferometry using later coda waves.

Interferometry with atoms

International Nuclear Information System (INIS)

Helmcke, J.; Riehle, F.; Witte, A.; Kisters, T.

1992-01-01

Physics and experimental results of atom interferometry are reviewed and several realizations of atom interferometers are summarized. As a typical example of an atom interferometer utilizing the internal degrees of freedom of the atom, we discuss the separated field excitation of a calcium atomic beam using four traveling laser fields and demonstrate the Sagnac effect in a rotating interferometer. The sensitivity of this interferometer can be largely increased by use of slow atoms with narrow velocity distribution. We therefore furthermore report on the preparation of a laser cooled and deflected calcium atomic beam. (orig.)

Basics of interferometry

CERN Document Server

Hariharan, P

1992-01-01

This book is for those who have some knowledge of optics, but little or no previous experience in interferometry. Accordingly, the carefully designed presentation helps readers easily find and assimilate the interferometric techniques they need for precision measurements. Mathematics is held to a minimum, and the topics covered are also summarized in capsule overviews at the beginning and end of each chapter. Each chapter also contains a set of worked problems that give a feel for numbers.The first five chapters present a clear tutorial review of fundamentals. Chapters six and seven discus

Speckle interferometry of asteroids

International Nuclear Information System (INIS)

Drummond, J.

1988-01-01

By studying the image two-dimensional power spectra or autocorrelations projected by an asteroid as it rotates, it is possible to locate its rotational pole and derive its three axes dimensions through speckle interferometry under certain assumptions of uniform, geometric scattering, and triaxial ellipsoid shape. However, in cases where images can be reconstructed, the need for making the assumptions is obviated. Furthermore, the ultimate goal for speckle interferometry of image reconstruction will lead to mapping albedo features (if they exist) as impact areas or geological units. The first glimpses of the surface of an asteroid were obtained from images of 4 Vesta reconstructed from speckle interferometric observations. These images reveal that Vesta is quite Moon-like in having large hemispheric-scale albedo features. All of its lightcurves can be produced from a simple model developed from the images. Although undoubtedly more intricate than the model, Vesta's lightcurves can be matched by a model with three dark and four bright spots. The dark areas so dominate one hemisphere that a lightcurve minimum occurs when the maximum cross-section area is visible. The triaxial ellipsoid shape derived for Vesta is not consistent with the notion that the asteroid has an equilibrium shape in spite of its having apparently been differentiated

Some applications of holographic interferometry in biomechanics

Science.gov (United States)

Ebbeni, Jean P. L.

1992-03-01

Holographic interferometry is well adapted for the determination of 2D strain fields in osseous structures. The knowledge of those strain fields is important for the understanding of structure behavior such as arthrosis.

Speckle Interferometry

Science.gov (United States)

Chiang, F. P.; Jin, F.; Wang, Q.; Zhu, N.

Before the milestone work of Leedertz in 1970 coherent speckles generated from a laser illuminated object are considered noise to be eliminated or minimized. Leedertz shows that coherent speckles are actually information carriers. Since then the speckle technique has found many applications to fields of mechanics, metrology, nondestructive evaluation and material sciences. Speckles need not be coherent. Artificially created socalled white light speckles can also be used as information carriers. In this paper we present two recent developments of speckle technique with applications to micromechanics problems using SIEM (Speckle Interferometry with Electron Microscopy), to nondestructive evaluation of crevice corrosion and composite disbond and vibration of large structures using TADS (Time-Average Digital Specklegraphy).

Azimuthally sensitive Hanbury Brown-Twiss interferometry measured with the ALICE experiment

Energy Technology Data Exchange (ETDEWEB)

Gramling, Johanna Lena

2011-07-01

Bose-Einstein correlations of identical pions emitted in high-energy particle collisions provide information about the size of the source region in space-time. If analyzed via HBT Interferometry in several directions with respect to the reaction plane, the shape of the source can be extracted. Hence, HBT Interferometry provides an excellent tool to probe the characteristics of the quark-gluon plasma possibly created in high-energy heavy-ion collisions. This thesis introduces the main theoretical concepts of particle physics, the quark gluon plasma and the technique of HBT interferometry. The ALICE experiment at the CERN Large Hadron Collider (LHC) is explained and the first azimuthallyintegrated results measured in Pb-Pb collisions at √(s{sub NN})=2.76 TeV with ALICE are presented. A detailed two-track resolution study leading to a global pair cut for HBT analyses has been performed, and a framework for the event plane determination has been developed. The results from azimuthally sensitive HBT interferometry are compared to theoretical models and previous measurements at lower energies. Oscillations of the transverse radii in dependence on the pair emission angle are observed, consistent with a source that is extended out-of-plane.

Scope of neutron interferometry

International Nuclear Information System (INIS)

Rauch, H.

1978-01-01

This paper deals with the interferometry of well separated coherent beams, where the phase of the beams can be manipulated individually. The basic equation of the dynamical neutron diffraction theory are recalled. The various contributions to the interaction of as low neutron with its surroundings are discussed: the various terms denote the nuclear, magnetic, electromagnetic, intrinsic, gravitational, and weak interaction respectively. Applications to nuclear physics, fundamental physics and solid state physics are successively envisaged

Spherical grating based x-ray Talbot interferometry

Energy Technology Data Exchange (ETDEWEB)

Cong, Wenxiang, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Xi, Yan, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Wang, Ge, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu [Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2015-11-15

Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

Spherical grating based x-ray Talbot interferometry

International Nuclear Information System (INIS)

Cong, Wenxiang; Xi, Yan; Wang, Ge

2015-01-01

Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

Interferometry with particles of non-zero rest mass: topological experiments

International Nuclear Information System (INIS)

Opat, G.I.

1994-01-01

Interferometry as a space-time process is described, together with its topology. Starting from this viewpoint, a convenient unified formalism for the phase shifts which arise in particle interferometry is developed. This formalism is based on a covariant form of Hamilton's action principle and Lagrange's equations of motion. It will be shown that this Lorentz invariant formalism yields a simple perturbation theoretic expression for the general phase shift that arises in matter-wave interferometry. The Lagrangian formalism is compared with the more usual formalism based on the wave propagation vector and frequency. The resulting formalism will be used to analyse the Sagnac effect, gravitational field measurements, and several Aharonov-Bohm-like topological phase shifts. Several topological interferometric experiments using particles of non-zero rest mass are discussed. These experiments involve the use of electrons, neutrons and neutral atoms. Neutron experiments will be emphasised. 45 refs., 15 figs

Theoretical investigations on dual-beam illumination electronic speckle pattern interferometry

International Nuclear Information System (INIS)

Goudemand, Nicolas

2006-01-01

Contrary to what is found in most of the existing scientific literature,where a specific frame is developed, the theory of speckle interferometry is (conveniently) presented here as a particular case of the more general theory of holographic interferometry. In addition to the intellectual benefit of dealing with a single unified theory, this brings about many advantages when it comes to discuss fundamental topics such as the three-dimensional evolution of the complex amplitude of the diffuse optical wave fronts, the degree of approximation of the leading formulas, the loss of fringe contrast,the decorrelation effects, the real influence of the terms generally neglected in out-of-focus regions. In the same way, the statistical properties of the speckle fields, usually treated as a separate subject matter, are also integrated in the theory, thus providing a comprehensive knowledge of the qualitative features of speckle interferometry methods, otherwise difficult to understand

Theoretical investigations on dual-beam illumination electronic speckle pattern interferometry

Science.gov (United States)

Goudemand, Nicolas

2006-07-01

Contrary to what is found in most of the existing scientific literature, where a specific frame is developed, the theory of speckle interferometry is (conveniently) presented here as a particular case of the more general theory of holographic interferometry. In addition to the intellectual benefit of dealing with a single unified theory, this brings about many advantages when it comes to discuss fundamental topics such as the three-dimensional evolution of the complex amplitude of the diffuse optical wavefronts, the degree of approximation of the leading formulas, the loss of fringe contrast, the decorrelation effects, the real influence of the terms generally neglected in out-of-focus regions. In the same way, the statistical properties of the speckle fields, usually treated as a separate subject matter, are also integrated in the theory, thus providing a comprehensive knowledge of the qualitative features of speckle interferometry methods, otherwise difficult to understand.

PNO-apparatus and its test use for neutron interferometry

International Nuclear Information System (INIS)

Tomimitsu, Hiroshi; Aizawa, Kazuya; Hasegawa, Yuji; Kikuta, Seishi.

1993-01-01

Special apparatus 'PNO' of multiutility in the so-called precise neutron optics, such as double or triple crystal diffractometry, interferometry, etc., including neutron diffraction topography, was settled at 3G beam hole in the JRR-3M. In the symposium, several applications of the PNO apparatus are presented as 1) very small angle neutron scattering tool with double crystal arrangement, 2) the characterization of the quality of artificial multilayer lattices made of Ti-Ni by a triple crystal arrangement, 3) the characterization of Ni-base superalloy single crystals by the diffraction topography, which are presented in individual sessions. Preliminary test of the neutron interferometry was also tried with the PNO apparatus. Usual monolithic Si LLL- type interferometer was used with an Al phase shifter in the neutron beam paths. The periodicity of the measured intensity curve was well corresponded to the expected one. The best contrast of the intensity curve was measured as high as 43%. The utility of the PNO-apparatus for neutron interferometry was, thus, approved. (author)

Improved operation of the Michelson interferometer electron cyclotron emission diagnostic on DIII-D

International Nuclear Information System (INIS)

Austin, M.E.; Ellis, R.F.; Doane, J.L.; James, R.A.

1997-01-01

The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and a reduction of calibration error from 15% to 5%. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter-wavelength frequency and very stable transmission characteristics over time. Further reduction in error was realized through special signal processing of the calibration and plasma interferograms. copyright 1997 American Institute of Physics

Developing Wide-Field Spatio-Spectral Interferometry for Far-Infrared Space Applications

Science.gov (United States)

Leisawitz, David; Bolcar, Matthew R.; Lyon, Richard G.; Maher, Stephen F.; Memarsadeghi, Nargess; Rinehart, Stephen A.; Sinukoff, Evan J.

2012-01-01

Interferometry is an affordable way to bring the benefits of high resolution to space far-IR astrophysics. We summarize an ongoing effort to develop and learn the practical limitations of an interferometric technique that will enable the acquisition of high-resolution far-IR integral field spectroscopic data with a single instrument in a future space-based interferometer. This technique was central to the Space Infrared Interferometric Telescope (SPIRIT) and Submillimeter Probe of the Evolution of Cosmic Structure (SPECS) space mission design concepts, and it will first be used on the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). Our experimental approach combines data from a laboratory optical interferometer (the Wide-field Imaging Interferometry Testbed, WIIT), computational optical system modeling, and spatio-spectral synthesis algorithm development. We summarize recent experimental results and future plans.

Optical interferometry for biology and medicine

CERN Document Server

Nolte, David D

2012-01-01

This book presents the fundamental physics of optical interferometry as applied to biophysical, biological and medical research. Interference is at the core of many types of optical detection and is a powerful probe of cellular and tissue structure in interfererence microscopy and in optical coherence tomography. It is also the root cause of speckle and other imaging artefacts that limit range and resolution. For biosensor applications, the inherent sensitivity of interferometry enables ultrasensitive detection of molecules in biological samples for medical diagnostics. In this book, emphasis is placed on the physics of light scattering, beginning with the molecular origins of refraction as light propagates through matter, and then treating the stochastic nature of random fields that ultimately dominate optical imaging in cells and tissue. The physics of partial coherence plays a central role in the text, with a focus on coherence detection techniques that allow information to be selectively detected out of ...

Ultrathin Epitaxial Ferromagneticγ-Fe2O3Layer as High Efficiency Spin Filtering Materials for Spintronics Device Based on Semiconductors

KAUST Repository

Li, Peng; Xia, Chuan; Zhu, Zhiyong; Wen, Yan; Zhang, Qiang; Alshareef, Husam N.; Zhang, Xixiang

2016-01-01

In spintronics, identifying an effective technique for generating spin-polarized current has fundamental importance. The spin-filtering effect across a ferromagnetic insulating layer originates from unequal tunneling barrier heights for spin

Equiatomic quaternary Heusler alloys: A material perspective for spintronic applications

Energy Technology Data Exchange (ETDEWEB)

Bainsla, Lakhan, E-mail: lakhanbainsla@gmail.com, E-mail: suresh@phy.iitb.ac.in; Suresh, K. G., E-mail: lakhanbainsla@gmail.com, E-mail: suresh@phy.iitb.ac.in [Magnetic Materials Lab, Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India)

2016-09-15

Half-metallic ferromagnetic (HMF) materials show high spin polarization and are therefore interesting to researchers due to their possible applications in spintronic devices. In these materials, while one spin sub band has a finite density of states at the Fermi level, the other sub band has a gap. Because of their high Curie temperature (T{sub C}) and tunable electronic structure, HMF Heusler alloys have a special importance among the HMF materials. Full Heusler alloys with the stoichiometric composition X{sub 2}YZ (where X and Y are the transition metals and Z is a sp element) have the cubic L2{sub 1} structure with four interpenetrating fcc sublattices. When each of these four fcc sublattices is occupied by different atoms (XX′YZ), a quaternary Heusler structure with different structural symmetries (space group F-43m, #216) is obtained. Recently, these equiatomic quaternary Heusler alloys (EQHAs) with 1:1:1:1 stoichiometry have attracted a lot of attention due to their superior magnetic and transport properties. A special class of HMF materials identified recently is known as spin gapless semiconductors (SGS). The difference in this case, compared with HMFs, is that the density of states for one spin band is just zero at the Fermi level, while the other has a gap as in the case of HMFs. Some of the reported SGS materials belong to EQHAs family. This review is dedicated to almost all reported materials belonging to EQHAs family. The electronic structure and hence the physical properties of Heusler alloys strongly depend on the degree of structural order and distribution of the atoms in the crystal lattice. A variety of experimental techniques has been used to probe the structural parameters and degree of order in these alloys. Their magnetic properties have been investigated using the conventional methods, while the spin polarization has been probed by point contact Andreev reflection technique. The experimentally obtained values of saturation magnetization are

Investigation of shear distance in Michelson interferometer-based shearography for mechanical characterization

International Nuclear Information System (INIS)

Lee, Jung-Ryul; Yoon, Dong-Jin; Kim, Jung-Seok; Vautrin, Alain

2008-01-01

Shearography is a growing industrial field in both quantitative mechanical characterization and relatively qualitative non-destructive testing. In shearography, shear distance is the most important parameter to control measurement performances. In this paper, the role of the shear distance is systematically investigated, focusing on the application of full-field mechanical characterization. A modified Michelson interferometer is considered as the shearing device, which is most commonly adopted for mechanical characterization applications because it enables easy and precise shearing and phase shifting. This paper also includes theoretical and experimental investigations of the relationship between shear distance and performance issues such as the immeasurable zone in the target with discontinuity, signal-to-noise ratio, sensitivity and shear distortion. In addition, this study is verified with actual shearographic results and a phase-shifting grid method capable of full-field displacement evaluation in the submicrometer regime

Hyperfine spectrum measurement of an optically pumped far-infrared laser with a Michelson interferometer

International Nuclear Information System (INIS)

Zuo, Z G; Ling, F R; Wang, P; Liu, J S; Yao, J Q; Weng, C X

2013-01-01

In this letter, we present a Michelson interferometer for the hyperfine spectrum measurement of an optically pumped far-infrared laser with a highest frequency resolution of 3–5 GHz. CH 3 OH gas with a purity of 99.9%, is pumped by the CO 2 9P36 and 9R10 laser lines to generate terahertz lasers with frequencies of 2.52 and 3.11 THz, respectively. Moreover, except for the center frequency, which is in good agreement with theoretical work, some additional frequencies on both sides of the center frequency are obtained at a frequency interval of 0.15 THz. Meanwhile, the mechanism behind the observed experimental results is also investigated. (letter)

Performance of a Rapid-Scan Vacuum Michelson Interferometer at the NSLS

International Nuclear Information System (INIS)

Brierly, P.; Dumas, P.; Smith, M.; Williams, G.P.

2001-01-01

A commercial Nicolet Magna series rapid-scan Michelson Fourier Transform Infrared (FTIR) was installed in a vacuum housing and integrated into the U4IR beamline at the National Synchrotron Light Source at Brookhaven National Laboratory. The frequency reference laser was mounted outside vacuum, but the moving mirror mechanism and the dynamic alignment system for the fixed mirror were in vacuum. The performance of the instrument was measured in the usual way by measuring the repeatability of data collected under specific conditions of aperture, resolution and mirror scanning velocity. We briefly discuss the beamline design, to put the interferometer in context, then present signal to noise data which we discuss in terms of both instrument performance and also storage ring stability. Under optimal conditions, the instrument has a reproducibility of 0.01% in 1 minute of measuring time at a resolution of 2 cmss, -1 , over a range from 100-3000 cm -1

Spin dynamics in polarized neutron interferometry

International Nuclear Information System (INIS)

Buchelt, R.J.

2000-05-01

Since its first implementation in 1974, perfect crystal neutron interferometry has become an extremely successful method applicable to a variety of research fields. Moreover, it proved as an illustrative and didactically valuable experiment for the demonstration of the fundamental principles of quantum mechanics, the neutron being an almost ideal probe for the detection of various effects, as it interacts by all four forces of nature. For instance, the first experimental verification of the 4-pi-periodicity of spinor wave functions was performed with perfect crystal neutron interferometry, and it remains the only method known which demonstrates the quantum mechanical wave-particle-duality of massive particles at a macroscopic separation of the coherent matter waves of several centimeters. A particular position is taken herein by polarized neutron interferometry, which as a collective term comprises all techniques and experiments which not only aim at the coherent splitting and macroscopic separation of neutron beams in the interferometer with the purpose of their separate treatment, but which aim to do so with explicit employment of the spin-magnetic properties of the neutron as a fermion. Remarkable aspects may arise, for example, if nuclear and magnetic potentials are concurrently applied to a partial beam of the interferometer: among other results, it is found that - in perfect agreement to the theoretical predictions - the neutron beam leaving the interferometer features non-zero polarization, even if the incident neutron beam, and hence either of the partial beams, is unpolarized. The main emphasis of the present work lies on the development of an appropriate formalism that describes the effect of simultaneous occurrence of nuclear and magnetic interaction on the emerging intensity and polarization for an arbitrary number of sequential magnetic regions, so-called domains. The confrontation with subtle theoretical problems was inevitable during the experimental

Application of Young-Michelson and Brown-Twiss interferometers for determining geometric parameters of nonplanar rough objects

International Nuclear Information System (INIS)

Mandrosov, V I

2008-01-01

The possibility of using Young-Michelson and Brown-Twiss interferometers for measuring the angular dimensions and parameters of the surface shape of remote passively scattering and self-luminous nonplanar rough objects by optical radiation propagating from them is substantiated. The analysis is based on the properties of approximate transverse functions of field coherence B t and B t ' and intensity coherence B ti and B ti ' formed by the time averaging of the products of fields and intensities taken at two points of a receiving aperture (the prime denotes self-luminous objects). The averaging time is set to be much longer than the coherence time of radiation propagating from an object. It is shown that for the radiation coherence length much smaller than the depth of the visible region of the object, the functions B t and B t ' are proportional to the Fourier transform of the intensity distribution in the image of a remote object, which is the generalisation of the Van Cittert-Zernicke theorem to the case of a nonplanar object, while functions B ti and B ti ' are proportional to the squares of the modulus of the Fourier transform of this distribution. It is also shown that the recording of functions B t and B t ' with a Young-Michelson interferometer gives only the angular dimensions of the visible region of objects, whereas the recording of functions B ti and B ti ' with a Brown-Twiss interferometer allows one to find these dimensions and the radius of curvature of the object surface. (laser radiation scattering)

A review on organic spintronic materials and devices: II. Magnetoresistance in organic spin valves and spin organic light emitting diodes

Directory of Open Access Journals (Sweden)

Rugang Geng

2016-09-01

Full Text Available In the preceding review paper, Paper I [Journal of Science: Advanced Materials and Devices 1 (2016 128–140], we showed the major experimental and theoretical studies on the first organic spintronic subject, namely organic magnetoresistance (OMAR in organic light emitting diodes (OLEDs. The topic has recently been of renewed interest as a result of a demonstration of the magneto-conductance (MC that exceeds 1000% at room temperature using a certain type of organic compounds and device operating condition. In this report, we will review two additional organic spintronic devices, namely organic spin valves (OSVs where only spin polarized holes exist to cause magnetoresistance (MR, and spin organic light emitting diodes (spin-OLEDs where both spin polarized holes and electrons are injected into the organic emissive layer to form a magneto-electroluminescence (MEL hysteretic loop. First, we outline the major advances in OSV studies for understanding the underlying physics of the spin transport mechanism in organic semiconductors (OSCs and the spin injection/detection at the organic/ferromagnet interface (spinterface. We also highlight some of outstanding challenges in this promising research field. Second, the first successful demonstration of spin-OLEDs is reviewed. We also discuss challenges to achieve the high performance devices. Finally, we suggest an outlook on the future of organic spintronics by using organic single crystals and aligned polymers for the spin transport layer, and a self-assembled monolayer to achieve more controllability for the spinterface.

Adaption of the Michelson interferometer for a better understanding of the temporal coherence in lasers

Science.gov (United States)

Illarramendi, M. A.; Zubia, J.; Arrue, J.; Ayesta, I.

2017-08-01

In this work, we show a design of a laboratory exercise in which a digital camera has been coupled to a Michelson interferometer based on free-propagation arms. By using the camera, our students measure the evolution of the interference patterns as a function of the difference between the optical paths of the arms. In this way, they obtain the corresponding reduction of the contrast of the fringes. The analysis of the results allows one to calculate the coherence length, and also to relate the temporal coherence of the employed laser with its spectral line profile. The exercise has been carried out with two lasers, which present different coherence lengths.

Single atom spintronics

International Nuclear Information System (INIS)

Sullivan, M. R.; Armstrong, J. N.; Hua, S. Z.; Chopra, H. D.

2005-01-01

Full text: Single atom spintronics (SASS) represents the ultimate physical limit in device miniaturization. SASS is characterized by ballistic electron transport, and is a fertile ground for exploring new phenomena. In addition to the 'stationary' (field independent) scattering centers that have a small and fixed contribution to total transmission probability of electron waves, domain walls constitute an additional and enhanced source of scattering in these magnetic quantum point contacts (QPCs), the latter being both field and spin-dependent. Through the measurement of complete hysteresis loops as a function of quantized conductance, we present definitive evidence of enhanced backscattering of electron waves by atomically sharp domain walls in QPCs formed between microfabricated thin films [1]. Since domain walls move in a magnetic field, the magnitude of spin-dependent scattering changes as the QPC is cycled along its hysteresis loop. For example, as shown in the inset in Fig. 1, from zero towards saturation in a given field direction, the resistance varies as the wall is being swept away, whereas the resistance is constant upon returning from saturation towards zero, since in this segment of the hysteresis loop no domain wall is present across the contact. The observed spin-valve like behavior is realized by control over wall width and shape anisotropy. This behavior also unmistakably sets itself apart from any mechanical artifacts; additionally, measurements made on single atom contacts provide an artifact-free environment [2]. Intuitively, it is simpler to organize the observed BMR data according to all possible transitions between different conductance plateaus, as shown by the dotted line in Fig. 1; the solid circles show experimental data for Co, which follows the predicted scheme. Requisite elements for the observation of the effect will be discussed in detail along with a review of state of research in this field. Practically, the challenge lies in making

Spintronics with metals: Current perpendicular-to-the-plane magneto-transport studies

Science.gov (United States)

Sharma, Amit

In this thesis, we present studies to produce new information about three topics: current perpendicular to the plane magnetoresistance (CPP-MR), spin transfer torque (STT), and antiferromagnetic spintronics. Large values of CPP-MR interface parameters---specific interface resistance (Area times resistance), 2AR*, and scattering asymmetry, gamma---are desirable for the use of CPP-MR in devices. Stimulated by a nanopillar study by the Cornell Group, we first discovered that Py/Al had an unusually large 2AR*, but a small gamma. In the hope of finding metal pairs with large values of both the interface parameters, the Py/Al studies led us to study the following interfaces: (a) F/Al with F: Py (= Ni84Fe16). Co, Fe, Co91Fe9, and (b) F/N: Py/Pd, Fe/V, Fe/Nb and Co/Pt. None of the metal pairs looks better for CPP-MR devices. The Cornell group also found that bracketing Al with thin Cu in Py/Al/Py nanopillars, gave an MR similar to Py/Al/Py rather than to Py/Cu/Py. To try to understand this result, we studied the effect of Cu/Al/Cu spacers on ADeltaR = AR(AP) - AR(P) of Py exchange biased spin valves (EBSVs). Here AR(AP) and AR(P) are the specific resistances in the anti-parallel (AP) and parallel (P) configurations of the F layers. Intriguingly, fixing the Al thickness tAl = 10 nm and varying tCu has no effect on ADeltaR, but fixing tCu = 10 nm and varying t Al significantly affected ADeltaR. These unusual behaviors are probably due to strong Al and Cu intermixing, with probable formation of some fraction of ordered alloys. Recent calculations predicted that 2AR of Al/Ag interfaces would vary substantially with orientation and with alloying. The latter is a special potential problem, because Al and Ag interdiffuse at room temperature. To compare with the calculations, we determined 2AR of sputtered Al/Ag interfaces with (111) orientation. Our estimate agrees with calculations that assume 4 monolayers of interfacial disorder, consistent with modest intermixing. To aid in

Spin-filter scanning tunneling microscopy : a novel technique for the analysis of spin polarization on magnetic surfaces and spintronic devices

NARCIS (Netherlands)

Vera Marun, I.J.

2010-01-01

This thesis deals with the development of a versatile technique to measure spin polarization with atomic resolution. A microscopy technique that can measure electronic spin polarization is relevant for characterization of magnetic nanostructures and spintronic devices. Scanning tunneling microscopy

Studies of Gravity Waves Using Michelson Interferometer Measurements of OH (3-1) Bands

Science.gov (United States)

Won, Young-In; Cho, Young-Min; Lee, Bang Yong; Kim, J.

2001-06-01

As part of a long-term program for polar upper atmospheric studies, temperatures and intensities of the OH (3-1) bands were derived from spectrometric observations of airglow emissions over King Sejong station (62.22o S, 301.25o E). These measurements were made with a Michelson interferometer to cover wavelength regions between 1000 nm and 2000 nm. A spectral analysis was performed to individual nights of data to acquire information on the waves in the upper mesosphere/lower thermosphere. It is assumed that the measured fluctuations in the intensity and temperature of the OH (3-1) airglow were caused by gravity waves propagating through the emission layer. Correlation of intensity and temperature variation revealed oscillations with periods ranging from 2 to 9 hours. We also calculated Krassovsky's parameter and compared with published values.

Characterization methods of integrated optics for mid-infrared interferometry

Science.gov (United States)

Labadie, Lucas; Kern, Pierre Y.; Schanen-Duport, Isabelle; Broquin, Jean-Emmanuel

2004-10-01

his article deals with one of the important instrumentation challenges of the stellar interferometry mission IRSI-Darwin of the European Space Agency: the necessity to have a reliable and performant system for beam combination has enlightened the advantages of an integrated optics solution, which is already in use for ground-base interferometry in the near infrared. Integrated optics provides also interesting features in terms of filtering, which is a main issue for the deep null to be reached by Darwin. However, Darwin will operate in the mid infrared range from 4 microns to 20 microns where no integrated optics functions are available on-the-shelf. This requires extending the integrated optics concept and the undergoing technology in this spectral range. This work has started with the IODA project (Integrated Optics for Darwin) under ESA contract and aims to provide a first component for interferometry. In this paper are presented the guidelines of the characterization work that is implemented to test and validate the performances of a component at each step of the development phase. We present also an example of characterization experiment used within the frame of this work, is theoretical approach and some results.

Heisenberg-limited interferometry with pair coherent states and parity measurements

International Nuclear Information System (INIS)

Gerry, Christopher C.; Mimih, Jihane

2010-01-01

After reviewing parity-measurement-based interferometry with twin Fock states, which allows for supersensitivity (Heisenberg limited) and super-resolution, we consider interferometry with two different superpositions of twin Fock states, namely, two-mode squeezed vacuum states and pair coherent states. This study is motivated by the experimental challenge of producing twin Fock states on opposite sides of a beam splitter. We find that input two-mode squeezed states, while allowing for Heisenberg-limited sensitivity, do not yield super-resolutions, whereas both are possible with input pair coherent states.

Future prospects for stellar intensity interferometry

International Nuclear Information System (INIS)

Lake, R.J.W.

2002-01-01

Full text: The technique of Stellar Intensity lnterferometry (SII) was first successfully demonstrated by Hanbury-Brown in 1956 at Jodrell Bank. SII uses the correlation in intensity fluctuations of starlight as a function of observational baseline to determine angular diameters and other gross features of main sequence stars. In 1962 an observatory was established by Hanbury-Brown in Narrabri NSW. Between 1965 and 1972 the angular diameters of 32 stars covering the spectral range O to F were measured. Orbital parameters of several unresolved binary stars were also determined and attempts were made by the author to directly measure the limb darkening of Sirius and the rotational distortion of Altair. Following the success of the Narrabri SII the Australian Federal Government provided a grant to Sydney University to develop a Very Large SII capable of making observational measurements on about a thousand stars. The development of this VLSII was however shelved in preference to the development of a potentially more sensitive long baseline Michelson Stellar Interferometer. This latter instrument known as SUSI (Sydney University Stellar Interferometer) has been in operation at Narrabri since 1995. Encouraged by the early results of SUSI and their own efforts in the use of active optics to reduce the effects of atmospheric scintillation a number of international observatories are now active in the development of long baseline or large aperture Michelson Stellar Interferometers. However SII while sacrificing sensitivity has a number of technical advantages over MSI as SII is far less sensitive to atmospheric effects and can be readily developed to work over very long baselines. This paper through technical review and theoretical modeling examines how a modern VLSII could be constructed and operated and addresses the limitations to its sensitivity. In particular it examines how existing Australian industry could contribute to the development of a VLSII with sufficient

The compact and inexpensive arrowhead setup for holographic interferometry

Energy Technology Data Exchange (ETDEWEB)

Ladera, Celso L; Donoso, Guillermo, E-mail: clladera@usb.v [Departamento de Fisica, Universidad Simon BolIvar, Apdo. 89000, Caracas 1086 (Venezuela, Bolivarian Republic of)

2011-07-15

Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that requires neither a collimator nor a beam-splitter, and whose layout is reminiscent of an arrowhead. We show that this inexpensive setup is a good alternative for the study and applications of scientific holography by measuring small displacements and deformations of a body. The arrowhead setup will be found particularly useful for holography and holographic interferometry experiments and projects in teaching laboratories.

Large resistance change on magnetic tunnel junction based molecular spintronics devices

Science.gov (United States)

Tyagi, Pawan; Friebe, Edward

2018-05-01

Molecular bridges covalently bonded to two ferromagnetic electrodes can transform ferromagnetic materials and produce intriguing spin transport characteristics. This paper discusses the impact of molecule induced strong coupling on the spin transport. To study molecular coupling effect the octametallic molecular cluster (OMC) was bridged between two ferromagnetic electrodes of a magnetic tunnel junction (Ta/Co/NiFe/AlOx/NiFe/Ta) along the exposed side edges. OMCs induced strong inter-ferromagnetic electrode coupling to yield drastic changes in transport properties of the magnetic tunnel junction testbed at the room temperature. These OMCs also transformed the magnetic properties of magnetic tunnel junctions. SQUID and ferromagnetic resonance studies provided insightful data to explain transport studies on the magnetic tunnel junction based molecular spintronics devices.

Simulation of a spintronic transistor: A study of its performance

International Nuclear Information System (INIS)

Pela, R.R.; Teles, L.K.

2009-01-01

We study theoretically the magnetic bipolar transistor, and compare its performance with common bipolar transistor. We present not only the simulation results for the characteristic curves, but also other relevant parameters related with its performance, such as: the current amplification factor, the open-loop gain, the hybrid parameters and the cutoff frequency. We noted that the spin-charge coupling introduces new phenomena that enrich the functionality characteristics of the magnetic bipolar transistor. Among other things, it has an adjustable band structure, which may be modified during the device operation; it exhibits the already known spin-voltaic effect. On the other hand, we observed that it is necessary a large g-factor to analyze the influence of the field B over the transistor. Nevertheless, we consider the magnetic bipolar transistor as a promising device for spintronic applications

Large-scale fabrication of BN tunnel barriers for graphene spintronics

International Nuclear Information System (INIS)

Fu, Wangyang; Makk, Péter; Maurand, Romain; Bräuninger, Matthias; Schönenberger, Christian

2014-01-01

We have fabricated graphene spin-valve devices utilizing scalable materials made from chemical vapor deposition (CVD). Both the spin-transporting graphene and the tunnel barrier material are CVD-grown. The tunnel barrier is realized by Hexagonal boron nitride, used either as a monolayer or bilayer and placed over the graphene. Spin transport experiments were performed using ferromagnetic contacts deposited onto the barrier. We find that spin injection is still greatly suppressed in devices with a monolayer tunneling barrier due to resistance mismatch. This is, however, not the case for devices with bilayer barriers. For those devices, a spin relaxation time of ∼260 ps intrinsic to the CVD graphene material is deduced. This time scale is comparable to those reported for exfoliated graphene, suggesting that this CVD approach is promising for spintronic applications which require scalable materials

Monitoring civil infrastructure using satellite radar interferometry

NARCIS (Netherlands)

Chang, L.

2015-01-01

Satellite radar interferometry (InSAR) is a precise and efficient technique to monitor deformation on Earth with millimeter precision. Most InSAR applications focus on geophysical phenomena, such as earthquakes, volcanoes, or subsidence. Monitoring civil infrastructure with InSAR is relatively new,

Time-lapse controlled-source electromagnetics using interferometry

NARCIS (Netherlands)

Hunziker, J.W.; Slob, E.C.; Wapenaar, C.P.A.

In time-lapse controlled-source electromagnetics, it is crucial that the source and the receivers are positioned at exactly the same location at all times of measurement. We use interferometry by multidimensional deconvolution (MDD) to overcome problems in repeatability of the source location.

The digital holographic interferometry in resonant acoustic spectroscopy

International Nuclear Information System (INIS)

GAPONOV, V.E.; AZAMATOV, Z.T.; REDKORECHEV, V.I.; ISAEV, A.M.

2014-01-01

The opportunities of application of digital holographic interferometry method for studies of shapes of resonant modes in resonant acoustic spectroscopy are shown. The results of experimental measurements and analytical calculations are submitted. (authors)

Neutron Interferometry at the National Institute of Standards and Technology

International Nuclear Information System (INIS)

Huber, M. G.; Sarenac, D.; Nsofini, J.; Pushin, D. A.; Arif, M.; Wood, C. J.; Cory, D. G.; Shahi, C. B.

2015-01-01

Neutron interferometry has proved to be a very precise technique for measuring the quantum mechanical phase of a neutron caused by a potential energy difference between two spatially separated neutron paths inside interferometer. The path length inside the interferometer can be many centimeters (and many centimeters apart) making it very practical to study a variety of samples, fields, potentials, and other macroscopic medium and quantum effects. The precision of neutron interferometry comes at a cost; neutron interferometers are very susceptible to environmental noise that is typically mitigated with large, active isolated enclosures. With recent advances in quantum information processing especially quantum error correction (QEC) codes we were able to demonstrate a neutron interferometer that is insensitive to vibrational noise. A facility at NIST’s Center for Neutron Research (NCNR) has just been commissioned with higher neutron flux than the NCNR’s older interferometer setup. This new facility is based on QEC neutron interferometer, thus improving the accessibility of neutron interferometry to the greater scientific community and expanding its applications to quantum computing, gravity, and material research

ECE diagnostic for the TARA tandem mirror machine using a fast-scanning Michelson interferometer

International Nuclear Information System (INIS)

Guharay, S.K.; Boyd, D.A.; Ellis, R.F.

1986-01-01

This ECE (electron cyclotron emission) diagnostic utilizes a fast-scanning Michelson interferometer to determine two parameters, the temperature and the loss cone angle, of the distribution function of the hot electrons (Tapprox. >100 keV) generated in the axisymmetric plug plasma of the TARA tandem mirror device. The radiation transport system employs a lens relay and a low-pass grating filter in order to transmit the synchrotron radiation over a spectral range of 2.9--18.6 cm -1 . This enables us to study the emitted radiation spectrum up to the 40th harmonic of the electron--cyclotron frequency in the plug plasma (B = 5 kG). Details of the design principles and the development of the diagnostic at TARA will be presented

Measurements of refractive indices and thermo-optical coefficients using a white-light Michelson interferometer.

Science.gov (United States)

Rocha, A C P; Silva, J R; Lima, S M; Nunes, L A O; Andrade, L H C

2016-08-20

A dispersive white-light Michelson interferometer was used to determine the wavelength dependence of the refractive index (n) in the visible range from 425 to 775 nm and the thermo-optical coefficient (dn/dT) of fused silica (FS) and borosilicate glass (BK7). For FS, the values obtained for n and dn/dT at 546 nm were 1.46079 and 11.3×10-6  K-1, respectively, while the values for BK7 glass were 1.51825 and 2.2×10-6  K-1, respectively, which is in good agreement with the literature. The accuracy of the methodology used for n was almost 10-6, enabling precise spectroscopic characterization of materials across a wide spectral range.

Frequency locking of a field-widened Michelson interferometer based on optimal multi-harmonics heterodyning.

Science.gov (United States)

Cheng, Zhongtao; Liu, Dong; Zhou, Yudi; Yang, Yongying; Luo, Jing; Zhang, Yupeng; Shen, Yibing; Liu, Chong; Bai, Jian; Wang, Kaiwei; Su, Lin; Yang, Liming

2016-09-01

A general resonant frequency locking scheme for a field-widened Michelson interferometer (FWMI), which is intended as a spectral discriminator in a high-spectral-resolution lidar, is proposed based on optimal multi-harmonics heterodyning. By transferring the energy of a reference laser to multi-harmonics of different orders generated by optimal electro-optic phase modulation, the heterodyne signal of these multi-harmonics through the FWMI can reveal the resonant frequency drift of the interferometer very sensitively within a large frequency range. This approach can overcome the locking difficulty induced by the low finesse of the FWMI, thus contributing to excellent locking accuracy and lock acquisition range without any constraint on the interferometer itself. The theoretical and experimental results are presented to verify the performance of this scheme.

Photopolymer for Optical Holography and Holographic Interferometry

Czech Academy of Sciences Publication Activity Database

Květoň, M.; Lédl, Vít; Havránek, A.; Fiala, P.

2010-01-01

Roč. 295, č. 1 (2010), s. 107-113 ISSN 1022-1360 Institutional research plan: CEZ:AV0Z20430508 Keywords : holographic interferometry * holography * photopolymerization * recording material * refractive index Subject RIV: BH - Optics, Masers, Lasers http://onlinelibrary.wiley.com/doi/10.1002/masy.200900093/pdf

Two-dimensional χ2 analysis in kaon interferometry

International Nuclear Information System (INIS)

Roldao, C.G.; Padula, S.S.

1997-01-01

This work presents preliminary results obtained from the χ 2 analysis performed on the E 859 Joint Work data. The work objective is to quantify the resolution power of the kaon two-dimension interferometry

Attosecond electron wave packet interferometry

International Nuclear Information System (INIS)

Remetter, T.; Ruchon, T.; Johnsson, P.; Varju, K.; Gustafsson, E.

2006-01-01

Complete test of publication follows. The well controlled generation and characterization of attosecond XUV light pulses provide an unprecedented tool to study electron wave packets (EWPs). Here a train of attosecond pulses is used to create and study the phase of an EWP in momentum space. There is a clear analogy between electronic wave functions and optical fields. In optics, methods like SPIDER or wave front shearing interferometry, allow to measure the spectral or spatial phase of a light wave. These two methods are based on the same principle: an interferogram is produced when recombining two sheared replica of a light pulse, spectrally (SPIDER) or spatially (wave front shearing interferometry). This enables the comparison of two neighbouring different spectral or spatial slices of the original wave packet. In the experiment, a train of attosecond pulses is focused in an Argon atomic gas jet. EWPs are produced from the single XUV photon ionization of Argon atoms. If an IR beam is synchronized to the EWPs, it is possible to introduce a shear in momentum space between two consecutive s wave packets. A Velocity Map Imaging Spectrometer (VMIS) enables us to detect the interference pattern. An analysis of the interferograms will be presented leading to a conclusion about the symmetry of the studied wave packet.

Broadband micro-Michelson interferometer with multi-optical-path beating using a sphered-end hollow fiber.

Science.gov (United States)

Chen, Nan-Kuang; Lu, Kuan-Yi; Shy, Jow-Tsong; Lin, Chinlon

2011-06-01

We demonstrate a high-sensitivity broadband (1250-1650 nm) fiber micro-Michelson interferometer using a single-mode fiber end-spliced with a sphered-end hollow-core fiber. The hollow core is slightly smaller than the solid core of a single-mode fiber, so the fractional power of the core mode is converted into cladding modes. The excited cladding modes propagate at distinct optical paths along the hollow-core fiber and have individual foci outside the spherical lens. The reflected core mode, generated at the solid core-air interface, and the reflected cladding modes, generated at external material, interfere with each other to produce beating in the interference signals. © 2011 Optical Society of America

Polarization Beam Splitter Based on a Self-Collimation Michelson Interferometer in a Silicon Photonic Crystal

International Nuclear Information System (INIS)

Chen Xi-Yao; Lin Gui-Min; Li Jun-Jun; Xu Xiao-Fu; Jiang Jun-Zhen; Qiang Ze-Xuan; Qiu Yi-Shen; Li Hui

2012-01-01

A polarization beam splitter based on a self-collimation Michelson interferometer (SMI) in a hole-type silicon photonic crystal is proposed and numerically demonstrated. Utilizing the polarization dependence of the transmission spectra of the SMI and polarization peak matching method, the SMI can work as a polarization beam splitter (PBS) by selecting an appropriate path length difference in the structure. Based on its novel polarization beam splitting mechanics, the polarization extinction ratios (PERs) for TM and TE modes are as high as 18.4 dB and 24.3 dB, respectively. Since its dimensions are only several operating wavelengths, the PBS may have practical applications in photonic integrated circuits. (fundamental areas of phenomenology(including applications))

A recent history of science cases for optical interferometry

Science.gov (United States)

Defrère, Denis; Aerts, Conny; Kishimoto, Makoto; Léna, Pierre

2018-04-01

Optical long-baseline interferometry is a unique and powerful technique for astronomical research. Since the 1980's (with I2T, GI2T, Mark I to III, SUSI, ...), optical interferometers have produced an increasing number of scientific papers covering various fields of astrophysics. As current interferometric facilities are reaching their maturity, we take the opportunity in this paper to summarize the conclusions of a few key meetings, workshops, and conferences dedicated to interferometry. We present the most persistent recommendations related to science cases and discuss some key technological developments required to address them. In the era of extremely large telescopes, optical long-baseline interferometers will remain crucial to probe the smallest spatial scales and make breakthrough discoveries.

Basic radio interferometry for future lunar missions

NARCIS (Netherlands)

Aminaei, Amin; Klein Wolt, Marc; Chen, Linjie; Bronzwaer, Thomas; Pourshaghaghi, Hamid Reza; Bentum, Marinus Jan; Falcke, Heino

2014-01-01

In light of presently considered lunar missions, we investigate the feasibility of the basic radio interferometry (RIF) for lunar missions. We discuss the deployment of two-element radio interferometer on the Moon surface. With the first antenna element is envisaged to be placed on the lunar lander,

Permafrost Active Layer Seismic Interferometry Experiment (PALSIE).

Energy Technology Data Exchange (ETDEWEB)

Abbott, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Knox, Hunter Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); James, Stephanie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lee, Rebekah [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cole, Chris [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-01-01

We present findings from a novel field experiment conducted at Poker Flat Research Range in Fairbanks, Alaska that was designed to monitor changes in active layer thickness in real time. Results are derived primarily from seismic data streaming from seven Nanometric Trillium Posthole seismometers directly buried in the upper section of the permafrost. The data were evaluated using two analysis methods: Horizontal to Vertical Spectral Ratio (HVSR) and ambient noise seismic interferometry. Results from the HVSR conclusively illustrated the method's effectiveness at determining the active layer's thickness with a single station. Investigations with the multi-station method (ambient noise seismic interferometry) are continuing at the University of Florida and have not yet conclusively determined active layer thickness changes. Further work continues with the Bureau of Land Management (BLM) to determine if the ground based measurements can constrain satellite imagery, which provide measurements on a much larger spatial scale.

Observations of binary stars by speckle interferometry

International Nuclear Information System (INIS)

Morgan, B.L.; Beckmann, G.K.; Scaddan, R.J.

1980-01-01

This is the second paper in a series describing observations of binary stars using the technique of speckle interferometry. Observations were made using the 2.5-m Isaac Newton Telescope and the 1-m telescope of the Royal Greenwich Observatory and the 1.9-m telescope of the South African Astronomical Observatory. The classical Rayleigh diffraction limits are 0.050 arcsec for the 2.5-m telescope, 0.065 arcsec for the 1.9-m telescope and 0.125 arcsec for the 1-m telescope, at a wavelength of 500 nm. The results of 29 measurements of 26 objects are presented. The objects include long period spectroscopic binaries from the 6th Catalogue of Batten, close visual binary systems from the 3rd Catalogue of Finsen and Worley and variable stars. Nine of the objects have not been previously resolved by speckle interferometry. New members are detected in the systems β Cep, p Vel and iota UMa. (author)

Studies of Gravity Waves Using Michelson Interferometer Measurements of OH (3-1 Bands

Directory of Open Access Journals (Sweden)

Young-In Won

2001-06-01

Full Text Available As part of a long-term program for polar upper atmospheric studies, temperatures and intensities of the OH (3-1 bands were derived from spectrometric observations of airglow emissions over King Sejong station (62.22o S, 301.25o E. These measurements were made with a Michelson interferometer to cover wavelength regions between 1000 nm and 2000 nm. A spectral analysis was performed to individual nights of data to acquire information on the waves in the upper mesosphere/lower thermosphere. It is assumed that the measured fluctuations in the intensity and temperature of the OH (3-1 airglow were caused by gravity waves propagating through the emission layer. Correlation of intensity and temperature variation revealed oscillations with periods ranging from 2 to 9 hours. We also calculated Krassovsky's parameter and compared with published values.

All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

International Nuclear Information System (INIS)

Malak, M.; Marty, F.; Bourouina, T.; Nouira, H.; Vailleau, G.

2013-01-01

A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

Energy Technology Data Exchange (ETDEWEB)

Malak, M.; Marty, F.; Bourouina, T. [Universite Paris-Est, Laboratoire ESYCOM, ESIEE Paris, Cite Descartes, 2 Boulevard Blaise Pascal, 93162 Noisy-le-Grand Cedex (France); Nouira, H.; Vailleau, G. [Laboratoire National de Metrologie et d' Essais, 1 rue Gaston Boissier, 75724 Paris Cedex 15 (France)

2013-04-08

A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

Optical-feedback semiconductor laser Michelson interferometer for displacement measurements with directional discrimination

International Nuclear Information System (INIS)

Rodrigo, Peter John; Lim, May; Saloma, Caesar

2001-01-01

An optical-feedback semiconductor laser Michelson interferometer (OSMI) is presented for measuring microscopic linear displacements without ambiguity in the direction of motion. The two waves from the interferometer arms, one from the reference mirror and the other from the reflecting moving target, are fed back into the lasing medium (λ=830 nm), causing variations in the laser output power. We model the OSMI into an equivalent Fabry-Perot resonator and derive the dependence of the output power (and the junction voltage) on the path difference between the two interferometer arms. Numerical and experimental results consistently show that the laser output power varies periodically (period, λ/2) with path difference. The output power variation exhibits an asymmetric behavior with the direction of motion, which is used to measure, at subwavelength resolution, the displacement vector (both amplitude and direction) of the moving sample. Two samples are considered in the experiments: (i) a piezoelectric transducer and (ii) an audio speaker

Polarization-dependent in-line quasi-Michelson interferometer based on PM-PCF reflection.

Science.gov (United States)

Du, Yanying; Qiao, Xueguang; Rong, Qiangzhou; Zhang, Jing; Feng, Dingyi; Wang, Ruohui; Sun, Hao; Hu, Manli; Feng, Zhongyao

2013-05-20

An in-line fiber quasi-Michelson interferometer (IFQMI) working on reflection is proposed and experimentally demonstrated. The sensing head is fabricated by splicing a section of polarization-maintaining photonic crystal fiber (PM-PCF) with a lead-in single mode fiber (SMF). Some cladding modes are excited into the PM-PCF via the mismatch-core splicing interface between PM-PCF and SMF. Besides, two orthogonal polarized-modes are formed due to the inherent multiholes cladding structure of the PM-PCF. A well-defined interference pattern is obtained as the result of cladding-orthogonal modes interference. The IFQMI with 20 cm long PM-PCF is proposed for strain and torsion measurements. A strain sensitivity of -1.3 pm/με and a torsion sensitivity of -19.17 pm/deg are obtained, respectively. The proposed device with 10 cm long PM-PCF exhibits a considered temperature sensitivity of 9.9 pm/°C. The IFQMI has a compact structure and small size, making it a good candidate for multiparameter measurements.

Study of Fourier transform spectrometer based on Michelson interferometer wave-meter

Science.gov (United States)

Peng, Yuexiang; Wang, Liqiang; Lin, Li

2008-03-01

A wave-meter based on Michelson interferometer consists of a reference and a measurement channel. The voice-coiled motor using PID means can realize to move in stable motion. The wavelength of a measurement laser can be obtained by counting interference fringes of reference and measurement laser. Reference laser with frequency stabilization creates a cosine interferogram signal whose frequency is proportional to velocity of the moving motor. The interferogram of the reference laser is converted to pulse signal, and it is subdivided into 16 times. In order to get optical spectrum, the analog signal of measurement channel should be collected. The Analog-to-Digital Converter (ADC) for measurement channel is triggered by the 16-times pulse signal of reference laser. So the sampling rate is constant only depending on frequency of reference laser and irrelative to the motor velocity. This means the sampling rate of measurement channel signals is on a uniform time-scale. The optical spectrum of measurement channel can be processed with Fast Fourier Transform (FFT) method by DSP and displayed on LCD.

A Michelson interferometer/polarimeter on the Tokamak Fusion Test Reactor (TFTR)

International Nuclear Information System (INIS)

Park, H.K.; Mansfield, D.K.; Johnson, L.C.; Ma, C.H.

1987-01-01

A multichannel interferometer/polarimeter for the Tokamak Fusion Test Reactor (TFTR) has been developed in order to study the time dependent plasma current density (J/sub p/) and electron density (n/sub e/) profile simultaneously. The goal of the TFTR is demonstration of breakeven via dueuterium and tritium (DT) plasma. In order to be operated and maintained during DT operation phase, the system is designed based on the Michelson geometry which possesses intrinsic standing wave problems. So far, there has been no observable signals due to these standing waves. However, a standing wave resulted from the beam path design to achieve a optimum use of the laser power was found. This standing wave has not prevented initial 10 channel interferometer operation. However, a single channel polarimeter test indicated this standing wave was fatal for Faraday notation measurements. Techniques employing 1/2 wave plates and polarizers have been applied to eliminate this standing wave problem. The completion of 10 channel Faraday rotation measurements may be feasible in the near future

Seismic interferometry by crosscorrelation and by multidimensional deconvolution: a systematic comparison

Science.gov (United States)

Wapenaar, Kees; van der Neut, Joost; Ruigrok, Elmer; Draganov, Deyan; Hunziker, Jürg; Slob, Evert; Thorbecke, Jan; Snieder, Roel

2011-06-01

Seismic interferometry, also known as Green's function retrieval by crosscorrelation, has a wide range of applications, ranging from surface-wave tomography using ambient noise, to creating virtual sources for improved reflection seismology. Despite its successful applications, the crosscorrelation approach also has its limitations. The main underlying assumptions are that the medium is lossless and that the wavefield is equipartitioned. These assumptions are in practice often violated: the medium of interest is often illuminated from one side only, the sources may be irregularly distributed, and losses may be significant. These limitations may partly be overcome by reformulating seismic interferometry as a multidimensional deconvolution (MDD) process. We present a systematic analysis of seismic interferometry by crosscorrelation and by MDD. We show that for the non-ideal situations mentioned above, the correlation function is proportional to a Green's function with a blurred source. The source blurring is quantified by a so-called interferometric point-spread function which, like the correlation function, can be derived from the observed data (i.e. without the need to know the sources and the medium). The source of the Green's function obtained by the correlation method can be deblurred by deconvolving the correlation function for the point-spread function. This is the essence of seismic interferometry by MDD. We illustrate the crosscorrelation and MDD methods for controlled-source and passive-data applications with numerical examples and discuss the advantages and limitations of both methods.

Fiber-optic Michelson interferometer fixed in a tilted tube for direction-dependent ultrasonic detection

Science.gov (United States)

Gang, Tingting; Hu, Manli; Qiao, Xueguang; Li, JiaCheng; Shao, Zhihua; Tong, Rongxin; Rong, Qiangzhou

2017-01-01

A fiber-optic interferometer is proposed and demonstrated experimentally for ultrasonic detection. The sensor consists of a compact Michelson interferometer (MI), which is fixed in a tilted-tube end-face (45°). Thin gold films are used for the reflective coatings of two arms and one of the interference arms is etched serving as the sensing arm. The spectral sideband filter technique is used to interrogate the continuous and pulse ultrasonic signals (with frequency of 300 KHz). Furthermore, because of the asymmetrical structure of the sensor, it presents strong direction-dependent ultrasonic sensitivity, such that the sensor can be considered a vector detector. The experimental results show that the sensor is highly sensitive to ultrasonic signals, and thus it can be a candidate for ultrasonic imaging of seismic physical models.

Application of SAR interferometry to low-rate crustal deformation fields

Science.gov (United States)

Vincent, Paul

Differential SAR interferometry is applied to the study of low-rate interseismic crustal deformation fields along three regions of the San Adreas fault system: Salton Sea (southernmost region), Pinto Mountain fault (south-central region), and San Francisco Bay (northern region). New techniques are developed to analyze and model these low-rate deformation fields including constrained horizontal-vertical component deconvolution, deformation phase pattern analysis and strain field evolution modeling. Several new active faults were discovered as well as unmeasured activity on existing faults in the process of this SAR interferometry study. The feasibility and limitations of InSAR as a tool to study low-rate deformation fields is also addressed.

Interferometry using undulator sources

International Nuclear Information System (INIS)

Beguiristain, R.; Goldberg, K.A.; Tejnil, E.; Bokor, J.; Medecki, H.; Attwood, D.T.; Jackson, K.

1996-01-01

Optical systems for extreme ultraviolet (EUV) lithography need to use optical components with subnanometer surface figure error tolerances to achieve diffraction-limited performance [M.D. Himel, in Soft X-Ray Projection Lithography, A.M. Hawryluk and R.H. Stulen, eds. (OSA, Washington, D.C., 1993), 18, 1089, and D. Attwood et al., Appl. Opt. 32, 7022 (1993)]. Also, multilayer-coated optics require at-wavelength wavefront measurement to characterize phase effects that cannot be measured by conventional optical interferometry. Furthermore, EUV optical systems will additionally require final testing and alignment at the operational wavelength for adjustment and reduction of the cumulative optical surface errors. Therefore, at-wavelength interferometric measurement of EUV optics will be the necessary metrology tool for the successful development of optics for EUV lithography. An EUV point diffraction interferometer (PDI) has been developed at the Center for X-Ray Optics (CXRO) and has been already in operation for a year [K. Goldberg et al., in Extreme Ultra Lithography, D.T. Attwood and F. Zernike, eds. (OSA, Washington, D.C., 1994), K. Goldberg et al., Proc. SPIE 2437, to be published, and K. Goldberg et al., J. Vac. Sci. Technol. B 13, 2923 (1995)] using an undulator radiation source and coherent optics beamline at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. An overview of the PDI interferometer and some EUV wavefront measurements obtained with this instrument will be presented. In addition, future developments planned for EUV interferometry at CXRO towards the measurement of actual EUV lithography optics will be shown. copyright 1996 American Institute of Physics

Testing the resolving power of 2-D K+ K+ interferometry at Ags energies

International Nuclear Information System (INIS)

Roldao, Cristiane G.; Padula, Sandra S.

1998-01-01

Adopting a procedure previously proposed to quantitatively study pion interferometry, an equivalent 2-D X 2 analysis was performed to test the resolving power of that method when applied to less favorable conditions, i.e., when non significant contribution from long lived resonances is expected, as in kaon interferometry. For that purpose, use is made of the preliminary E859 K + K + interferometry data from Si+Au collisions at 14.6 A GeV/c. Less sensitivity is achieved in the present case, although it is shown that it is still possible to distinguish two distinct decoupling geometries. The possible compatibility of the data with zero decoupling proper time interval, suggested by the experimental fit, is also investigated and seems to be ruled out when considering dynamical models with expanding sources. (author)

Control sideband generation for dual-recycled laser interferometric gravitational wave detectors

International Nuclear Information System (INIS)

Barr, B W; Miyakawa, O; Kawamura, S; Weinstein, A J; Ward, R; Vass, S; Strain, K A

2006-01-01

We present a discussion of the problems associated with generation of multiple control sidebands for length sensing and control of dual-recycled, cavity-enhanced Michelson interferometers and the motivation behind more complicated sideband generation methods. We focus on the Mach-Zehnder interferometer as a topological solution to the problem and present results from tests carried out at the Caltech 40 m prototype gravitational wave detector. The consequences for sensing and control for advanced interferometry are discussed, as are the implications for future interferometers such as Advanced LIGO

Spintronics with graphene-hexagonal boron nitride van der Waals heterostructures

International Nuclear Information System (INIS)

Kamalakar, M. Venkata; Dankert, André; Bergsten, Johan; Ive, Tommy; Dash, Saroj P.

2014-01-01

Hexagonal boron nitride (h-BN) is a large bandgap insulating isomorph of graphene, ideal for atomically thin tunnel barrier applications. In this letter, we demonstrate large area chemical vapor deposited (CVD) h-BN as a promising spin tunnel barrier in graphene spin transport devices. In such structures, the ferromagnetic tunnel contacts with h-BN barrier are found to show robust tunneling characteristics over a large scale with resistances in the favorable range for efficient spin injection into graphene. The non-local spin transport and precession experiments reveal spin lifetime ≈500 ps and spin diffusion length ≈1.6 μm in graphene with tunnel spin polarization ≈11% at 100 K. The electrical and spin transport measurements at different injection bias current and gate voltages confirm tunnel spin injection through h-BN barrier. These results open up possibilities for implementation of large area CVD h-BN in spintronic technologies

Fabrication of tunnel junction-based molecular electronics and spintronics devices

International Nuclear Information System (INIS)

Tyagi, Pawan

2012-01-01

Tunnel junction-based molecular devices (TJMDs) are highly promising for realizing futuristic electronics and spintronics devices for advanced logic and memory operations. Under this approach, ∼2.5 nm molecular device elements bridge across the ∼2-nm thick insulator of a tunnel junction along the exposed side edge(s). This paper details the efforts and insights for producing a variety of TJMDs by resolving multiple device fabrication and characterization issues. This study specifically discusses (i) compatibility between tunnel junction test bed and molecular solutions, (ii) optimization of the exposed side edge profile and insulator thickness for enhancing the probability of molecular bridging, (iii) effect of fabrication process-induced mechanical stresses, and (iv) minimizing electrical bias-induced instability after the device fabrication. This research will benefit other researchers interested in producing TJMDs efficiently. TJMD approach offers an open platform to test virtually any combination of magnetic and nonmagnetic electrodes, and promising molecules such as single molecular magnets, porphyrin, DNA, and molecular complexes.

A differential Michelson interferometer with orthogonal single frequency laser for nanometer displacement measurement

International Nuclear Information System (INIS)

Yan, Liping; Chen, Benyong; Wang, Bin

2017-01-01

A novel differential Michelson laser interferometer is proposed to eliminate the influence of environmental fluctuations for nanometer displacement measurement. This differential interferometer consists of two homodyne interferometers in which two orthogonal single frequency beams share common reference arm and partial measurement arm. By modulating the displacement of the common reference arm with a piezoelectric transducer, the common-mode displacement drift resulting from the environmental disturbances can be well suppressed and the measured displacement as differential-mode displacement signal is achieved. In addition, a phase difference compensation method is proposed for accurately determining the phase difference between interference signals by correcting the time interval according to the average speed in one cycle of interference signal. The nanometer displacement measurement experiments were performed to demonstrate the effectiveness and feasibility of the proposed interferometer and show that precision displacement measurement with standard deviation less than 1 nm has been achieved. (paper)

Heterogeneous all-solid multicore fiber based multipath Michelson interferometer for high temperature sensing.

Science.gov (United States)

Duan, Li; Zhang, Peng; Tang, Ming; Wang, Ruoxu; Zhao, Zhiyong; Fu, Songnian; Gan, Lin; Zhu, Benpeng; Tong, Weijun; Liu, Deming; Shum, Perry Ping

2016-09-05

A compact high temperature sensor utilizing a multipath Michelson interferometer (MI) structure based on weak coupling multicore fiber (MCF) is proposed and experimentally demonstrated. The device is fabricated by program-controlled tapering the spliced region between single mode fiber (SMF) and a segment of MCF. After that, a spherical reflective structure is formed by arc-fusion splicing the end face of MCF. Theoretical analysis has been implemented for this specific multipath MI structure; beam propagation method based simulation and corresponding experiments were performed to investigate the effect of taper and spherical end face on system's performance. Benefiting from the multipath interferences and heterogeneous structure between the center core and surrounding cores of the all-solid MCF, an enhanced temperature sensitivity of 165 pm/°C up to 900°C and a high-quality interference spectrum with 25 dB fringe visibility were achieved.

Měření indexu lomu vzduchu pomocí interferometrie nízké koherence

Czech Academy of Sciences Publication Activity Database

Pikálek, Tomáš; Buchta, Zdeněk

2017-01-01

Roč. 62, č. 10 (2017), s. 253-256 ISSN 0447-6441 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : air refractive index * laser interferometry * low-coherence interferometry Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics)

Polarimetric SAR interferometry applied to land ice: modeling

DEFF Research Database (Denmark)

Dall, Jørgen; Papathanassiou, Konstantinos; Skriver, Henning

2004-01-01

This paper introduces a few simple scattering models intended for the application of polarimetric SAR interfer-ometry to land ice. The principal aim is to eliminate the penetration bias hampering ice sheet elevation maps generated with single-channel SAR interferometry. The polarimetric coherent...... scattering models are similar to the oriented-volume model and the random-volume-over-ground model used in vegetation studies, but the ice models are adapted to the different geometry of land ice. Also, due to compaction, land ice is not uniform; a fact that must be taken into account for large penetration...... depths. The validity of the scattering models is examined using L-band polarimetric interferometric SAR data acquired with the EMISAR system over an ice cap located in the percolation zone of the Greenland ice sheet. Radar reflectors were deployed on the ice surface prior to the data acquisition in order...

The role of ion-implantation in the realization of spintronic devices in diamond

Energy Technology Data Exchange (ETDEWEB)

Kalish, Rafi, E-mail: kalish@si-sun1.technion.ac.il [Physics Department and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

2012-02-01

The application of single photons emitted by specific quantum systems is promising for quantum computers, cryptography and for other future nano-applications. These heavily rely on ion implantation both for selective single ion implantations as well as for the introduction of controlled damage with specific properties. Of particular promise is the negatively charged nitrogen-vacancy (NV{sup -}) defect center in diamond. This center has many desirable luminescence properties required for spintronic devices operational at room temperature, including a long relaxation time of the color center, emission of photons in the visible and the fact that it is produced in diamond, a material with outstanding mechanical and optical properties. This center is usually realized by nitrogen and/or vacancy producing ion implantations into diamond which, following annealing, leads to the formation of the desired NV{sup -} center. The single photons emitted by the decay of this center have to be transported to allow their exploitation. This can be best done by realizing very thin wave guides in single crystal diamond with/or without nano-scale cavities in the same diamond in which NV centers are produced. For this, advantage is taken of the unique property of heavily ion-damaged diamond to be converted, following annealing, to etchable graphite. Thus a free standing submicron thick diamond membrane containing the NV center can be obtained. If desirable, specific photonic crystal structures can be realized in them by the use of FIB. The various ion-implantation schemes used to produce NV centers in diamond, free standing diamond membranes, and photonic crystal structures in them are reviewed. The scientific problems and the technological challenges that have to be solved before actual practical realization of diamond based spintronic devices can be produced are discussed.

Investigation of surface deformations by double exposure holographic interferometry

International Nuclear Information System (INIS)

Ecevit, F.N.; Guven, H.; Aydin, R.

1990-01-01

Surface deformations of rigid bodies produced by thermal as well as mechanical strains have been investigated using double-exposure holographic interferometry. The recorded interference fringes have been discussed qualitatively. (author). 9 refs, 4 figs

Neutron interferometry: The pioneering contributions of Samuel A. Werner

International Nuclear Information System (INIS)

Klein, A.G.

2006-01-01

In 1975, Sam Werner, while on the staff of the Scientific Laboratory of the Ford Motor Company, and his collaborators from Purdue University, Roberto Colella and Albert Overhauser, carried out one of the pioneering experiments in neutron interferometry at the 2 MW University of Michigan research reactor. It was the famous COW Experiment [Colella et al., Phys. Rev. Lett. 34 (1975) 1472] on gravitationally induced quantum interference. Shortly thereafter he moved to University of Missouri in Columbia, to set up a program of neutron scattering research, including neutron interferometry. In the 25 years until his retirement a large number of beautiful experiments have been performed by Sam, with his group, his numerous students and many international collaborators. This work and its history are briefly reviewed in this paper

Detecting mode hopping in single-longitudinal-mode fiber ring lasers based on an unbalanced fiber Michelson interferometer.

Science.gov (United States)

Ma, Mingxiang; Hu, Zhengliang; Xu, Pan; Wang, Wei; Hu, Yongming

2012-10-20

A method of detecting mode hopping for single-longitudinal-mode (SLM) fiber ring lasers has been proposed and experimentally demonstrated. The method that is based on an unbalanced Michelson interferometer (MI) utilizing phase generated carrier modulation instantly transforms mode-hopping dynamics into steep phase changes of the interferometer. Multiform mode hops in an SLM erbium-doped fiber ring laser with an 18.6 MHz mode spacing have been detected exactly in real-time domain and discussed in detail. Numerical results show that the MI-based method has a high testing sensitivity for identifying mode hopping, which will play a significant role in evaluating the output stability of SLM fiber lasers.

Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

Energy Technology Data Exchange (ETDEWEB)

Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

2014-09-08

A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

Radio astronomical interferometry and x-ray's computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, L F [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Astronomia

1982-01-01

Radio astronomical interferometry and computerized tomography are techniques of great importance for astronomy and medicine, respectively. In this paper we emphasize that both techniques are based on the same mathematical principles, and present them as an example of interaction between basic and applied science.

Global-scale seismic interferometry : Theory and numerical examples

NARCIS (Netherlands)

Ruigrok, E.N.; Draganov, D.S.; Wapenaar, K.

2008-01-01

Progress in the imaging of the mantle and core is partially limited by the sparse distribution of natural sources; the earthquake hypocenters are mainly along the active lithospheric plate boundaries. This problem can be approached with seismic interferometry. In recent years, there has been

Temporal characterization of short-pulse third-harmonic generation in an atomic gas by a transmission-grating Michelson interferometer.

Science.gov (United States)

Papadogiannis, N A; Nersisyan, G; Goulielmakis, E; Rakitzis, T P; Hertz, E; Charalambidis, D; Tsakiris, G D; Witte, K

2002-09-01

By use of a transmission-grating-based Michelson interferometer, second-order interferometric as well as intensity autocorrelation traces of the third harmonic of a Ti:sapphire 50-fs laser beam produced in Ar have been measured. The duration of the harmonic is found to be that expected from lowest-order perturbation theory. At this wavelength, the performance of the interferometer with respect to pulse-front distortion and dispersion is found to be satisfactory. This result is a first step toward the use of the interferometer for the temporal characterization of higher harmonics or harmonic superposition forming attosecond pulse trains.

Laser phase and frequency noise measurement by Michelson interferometer composed of a 3 × 3 optical fiber coupler.

Science.gov (United States)

Xu, Dan; Yang, Fei; Chen, Dijun; Wei, Fang; Cai, Haiwen; Fang, Zujie; Qu, Ronghui

2015-08-24

A laser phase and frequency noise measurement method by an unbalanced Michelson interferometer composed of a 3 × 3 optical fiber coupler is proposed. The relations and differences of the power spectral density (PSD) of differential phase and frequency fluctuation, PSD of instantaneous phase and frequency fluctuation, phase noise and linewidth are derived strictly and discussed carefully. The method obtains the noise features of a narrow linewidth laser conveniently without any specific assumptions or noise models. The technique is also used to characterize the noise features of a narrow linewidth external-cavity semiconductor laser, which confirms the correction and robustness of the method.

White light spectral interferometer for measuring dispersion in the visible-near infrared

Science.gov (United States)

Arosa, Yago; Rodríguez Fernández, Carlos Damian; Algnamat, Bilal S.; López-Lago, Elena; de la Fuente, Raul

2017-08-01

We have designed a spectrally resolved interferometer to measure the refractive index of transparent samples over a wide spectral band from 400 to 1550 nm. The measuring device consists of a Michelson interferometer whose output is analyzed by means of three fiber spectrometers. The first one is a homemade prism spectrometer, which obtains the interferogram produced by the sample over 400 to 1050 nm; the second one is a homemade transmission grating spectrometer thought to measure the interferogram in the near infrared spectral band from 950 to 1550 nm; the last one is a commercial Czerny-Turner spectrometer used to make high precision measurements of the displacement between the Michelson mirrors also using white light interferometry. The whole system is illuminated by a white light source with an emission spectrum similar to black body. We have tested the instrument with solid and liquids samples achieving accuracy to the fourth decimal on the refractive index after fitting it to a Cauchy formula

Use of the shearing interferometry for dense inhomogeneous plasma diagnostics

International Nuclear Information System (INIS)

Zakharenkov, Yu.A.; Sklizkov, G.V.; Shikanov, A.S.

1980-01-01

Investigated is a possibility of applying the shearing interferometry for diagnostics of a dense inhomogeneous laser plasma which makes it possible to measure the electron density without losses in accuracy near the critical surface. A shearing interferogram is formed upon interference of two identical images of the object under study shifted at some fixed distance. The value of the interference band deflection inside phase inhomogeneity depends on the gradient of the index of refraction in the direction of shift. It has been found that for studying the inner region of the laser plasma a small shift should be used, and for the external one - a large one. The version of a radial shift interferometry is shown to be optimum. For the inner region of the interferogram the error of the electron density restoration does not exceed 10%, and for the external one the error is comparable with that for the version of standard interferometry. A systematic analysis of the optimum type interferometers shows advantages of shearing interferometers. The maximum electron density recorded in experiments makes up approximately equal to 10 20 cm -3 , which is 3-5 times higher than the corresponding value obtained by a standard double-slit type interferometer at equal limiting parameters of the optical system applied

Very long baseline interferometry applied to polar motion, relativity, and geodesy. Ph.D. thesis

International Nuclear Information System (INIS)

Ma, C.

1978-01-01

The causes and effects of diurnal polar motion are described. An algorithm was developed for modeling the effects on very long baseline interferometry observables. A selection was made between two three-station networks for monitoring polar motion. The effects of scheduling and the number of sources observed on estimated baseline errors are discussed. New hardware and software techniques in very long baseline interferometry are described

Group IV all-semiconductor spintronics. Materials aspects and optical spin selection rules

Energy Technology Data Exchange (ETDEWEB)

Sircar, Narayan

2012-04-03

In the scope of the present thesis various aspects for the realization of spintronic applications based on group IV semiconductors are discussed. This work comprises a refined material characterization of the magnetic semiconductor GeMn. We furthermore present efforts to utilize this material as spin injector for a Si-based optical spintronic device. Applying transmission electron microscopy and atom probe tomography, we are able to resolve a vertical anisotropy in the self-assembly, leading to the stacking of well-defined clusters in the growth direction. Three-dimensional atom distribution maps confirm that clusters are built from a nonstoichiometric GeMn alloy and exhibit a high-Mn-concentration core with a decreasing Mn concentration toward a shell. An amorphous nature of the cluster cores as well as the crystallinity of the shells, coherent with the surrounding Ge lattice, are revealed in scanning transmission electron microscopy. We localize a strain field surrounding each GeMn cluster by scanning transmission electron microscopy. The importance of strain to the stacking phenomenon of the clusters becomes clear in studies of Ge/GeMn superlattice structures, where a vertical spatial correlation of clusters over 30 nm-thick Ge spacer layers is observed. We present evidence that electrical transport properties of the p-type GeMn thin films fabricated on high-resistivity Ge substrates are severely influenced by parallel conduction through the substrate. It is shown that substrate conduction persists also for wellconducting degenerate p-type reference thin films, giving rise to an effective two-layer conduction scheme. GeMn thin films fabricated on these substrates exhibit only a negligible magnetoresistance effect. Before integrating GeMn in an optical spintronic device, some key aspects important for an understanding of the optical injection and detection of carrier spins in Si and Si-based heterostructures are clarified in the second part of this thesis. In

Heterodyne Interferometry in InfraRed at OCA-Calern Observatory in the seventies

Science.gov (United States)

Gay, J.; Rabbia, Y.

2014-04-01

We report on various works carried four decades ago, so as to develop Heterodyne Interferometry in InfraRed (10 μm) at Calern Observatory (OCA, France), by building an experiment, whose the acronym "SOIRDETE" means "Synthese d'Ouverture en InfraRouge par Detection hETErodyne". Scientific and technical contexts by this time are recalled, as well as basic principles of heterodyne interferometry. The preliminary works and the SOIRDETE experiment are briefly described. Short comments are given in conclusion regarding the difficulties which have prevented the full success of the SOIRDETE experiment.

Interferometry with Vortices

Directory of Open Access Journals (Sweden)

P. Senthilkumaran

2012-01-01

Full Text Available Interference of optical beams with optical vortices is often encountered in singular optics. Since interferometry makes the phase observable by intensity measurement, it brings out a host of applications and helps to understand the optical vortex. In this article we present an optical vortex interferometer that can be used in optical testing and has the potential to increase the accuracy of measurements. In an optical vortex interferometer (OVI, a lattice of vortices is formed, and the movement of the cores of these vortices is tracked when one of the interfering beams is deformed. Instead of multiple vortices in an OVI, an isolated single vortex also finds applications in optical testing. Finally, singularity in scalar and vector fields is presented, and the relation between them is illustrated by the superposition of these beams.

Demystifying back scatter interferometry: a sensitive refractive index detector

DEFF Research Database (Denmark)

Jepsen, Søren Terpager; Jørgensen, Thomas Martini; Trydal, Torleif

2014-01-01

BACKGROUND: Back Scatter Interferometry (BSI) is a sensitive method for detecting changes of the refractive index (RI) in small capillaries. The method was originally developed as an off-axial column detector for use in Liquid Chromatography or Capillary Electrophoresis systems, but it has been...... acting like a common-path interferometer. METHODS: A HeNe laser is directed at a glass capillary with inner diameter of 1.4 mm and reflected light from air/glass and liquid/glass interfaces interfere to form an RI dependent intensity fringe pattern at a CCD detector. The fringe shift relative...... a common-path interferometer. The sensitivity of the BSI system is given by twice the inner diameter of the capillary times the wavenumber of the light source. Our results suggest that Back Scatter Interferometry does not provide a unique measurement principle for sensing biochemical bindings compared...

Understanding interferometry for micro-cantilever displacement detection

Directory of Open Access Journals (Sweden)

Alexander von Schmidsfeld

2016-06-01

Full Text Available Interferometric displacement detection in a cantilever-based non-contact atomic force microscope (NC-AFM operated in ultra-high vacuum is demonstrated for the Michelson and Fabry–Pérot modes of operation. Each mode is addressed by appropriately adjusting the distance between the fiber end delivering and collecting light and a highly reflective micro-cantilever, both together forming the interferometric cavity. For a precise measurement of the cantilever displacement, the relative positioning of fiber and cantilever is of critical importance. We describe a systematic approach for accurate alignment as well as the implications of deficient fiber–cantilever configurations. In the Fabry–Pérot regime, the displacement noise spectral density strongly decreases with decreasing distance between the fiber-end and the cantilever, yielding a noise floor of 24 fm/Hz0.5 under optimum conditions.

Polar cap mesosphere wind observations: comparisons of simultaneous measurements with a Fabry-Perot interferometer and a field-widened Michelson interferometer.

Science.gov (United States)

Fisher, G M; Killeen, T L; Wu, Q; Reeves, J M; Hays, P B; Gault, W A; Brown, S; Shepherd, G G

2000-08-20

Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (approximately 86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause.

Cost-Effective Magnetoencephalography Based on Time Encoded Optical Fiber Interferometry for Epilepsy and Tinnitus

Science.gov (United States)

2016-09-01

respectively. A length of dispersive fiber and a computer are used to first “decode” the optical interference signal into dispersed optical wave-packet...AWARD NUMBER: W81XWH-15-1-0008 TITLE: Cost-Effective Magnetoencephalography Based on Time-Encoded Optical Fiber Interferometry for Epilepsy...10 Dec 2014 - 9 Jun 2016 4. TITLE AND SUBTITLE 5a.16 CONTRACT NUMBER Encoded Optical Fiber Interferometry for Epilepsy and Tinnitus Diagnosis 5b

Development of angle-resolved low coherence interferometry for clinical detection of dysplasia

Directory of Open Access Journals (Sweden)

Yizheng Zhu

2011-01-01

Full Text Available This review covers the development of angle-resolved low coherence interferometry (a/LCI from initial development through clinical application. In the first applications, the approach used a time-domain interferometry scheme and was validated using animal models of carcinogenesis to assess the feasibility of detecting dysplasia in situ. Further development of the approach led to Fourier-domain interferometry schemes with higher throughput and endoscope-compatible probes to enable clinical application. These later implementations have been applied to clinical studies of dysplasia in Barrett′s esophagus tissues, a metaplastic tissue type that is associated with an increased risk of esophageal adenocarcinoma. As an alternative to systematic biopsy, the a/LCI approach offers high sensitivity and specificity for detecting dysplasia in these tissues while avoiding the need for tissue removal or exogenous contrast agents. Here, the various implementations of a/LCI are discussed and the results of the preliminary animal experiments and ex vivo human tissue studies are reviewed. A review of a recent in vivo clinical study is also presented.

An investigation of CO2 laser scleral buckling using moiré interferometry.

Science.gov (United States)

Maswadi, Saher M; Dyer, Peter E; Verma, Dinesh; Jalabi, Wadah; Dave, Dinesh

2002-01-01

To demonstrate suitability of moiré interferometry to assess and quantify laser-induced shrinkage of scleral collagen for buckling procedures. Scleral buckling of human cadaver eyes was investigated using a Coherent Ultrapulse CO2 laser. Projection moiré interferometry was employed to determine the out-of plane displacement produced by laser exposure, and in-situ optical microscopy of reference markers on the eye was used to measure in-plane shrinkage. Measurements based on moiré interferometry allow a three dimensional view of shape changes in the eye surface as laser treatment proceeds. Out-of-plane displacement reaches up to 1.5 mm with a single laser spot exposure. In-plane shrinkage reached a maximum of around 30%, which is similar to that reported by Sasoh et al (Ophthalmic Surg Lasers. 1998;29:410) for a Tm:YAG laser. The moiré technique is found to be suitable for quantifying the effects of CO2 laser scleral shrinkage and buckling. This can be further developed to provide a standardized method for experimental investigations of other laser sources for scleral shrinkage.

Multi-Axis Heterodyne Interferometry (MAHI)

Science.gov (United States)

Thorpe, James

The detection and measurement of gravitational waves represents humanity’s next, and final, opportunity to open an entirely new spectrum with which to view the universe. The first steps of this process will likely take place later this decade when the second-generation ground-based instruments such as Advanced LIGO approach design sensitivity. While these events will be historic, it will take a space-based detector to access the milliHertz gravitational wave frequency band, a band that is rich in both number and variety of sources. The Laser Interferometer Space Antenna (LISA) concept has been developed over the past two decades in the US and Europe to provide access to this band. The European Space Agency recently selected The Gravitational Universe as the science theme for the 3rd Large-class mission in the Cosmic Visions Programme, with the assumption that a LISA-like instrument would be implemented for launch in 2034. NASA has expressed interest in partnering on this effort and the US community has made its own judgment on the scientific potential of a space-based gravitational wave observatory through the selection of LISA as the 3rd flagship mission in the 2010 Decadal Survey. Much of the effort has been in retiring risk for the unique technologies that comprise a gravitational wave detector. A prime focus of this effort is LISA Pathfinder (LPF), a dedicated technology demonstrator mission led by ESA with contributions from NASA and several member states. LPF’s primary objective is to validate drag-free flight as an approach to realizing an inertial reference mass. Along the way, several important technologies will be demonstrated, including picometer-level heterodyne interferometry. However, there are several important differences between the interferometry design for LISA and that for LPF. These mostly result from the fact that LISA interferometry involves multiple lasers on separate spacecraft whereas LPF can use a single laser on a single spacecraft

The Design and Implementation of the Wide-Angle Michelson Interferometer to Observe Thermospheric Winds.

Science.gov (United States)

Ward, William Edmund

The design and implementation of a Wide-Angle Michelson interferometer (WAMI) as a high spectral resolution device for measuring Doppler shifts and temperatures in the thermosphere is discussed in detail. A general theoretical framework is developed to describe the behavior of interferometers and is applied to the WAMI. Notions concerning the optical coupling of various surfaces within an interferometer are developed and used to investigate the effects of misalignments in the WAMI optics. In addition, these notions in combination with ideas on the polarization behavior of interferometers are used to suggest how complex multisurfaced interferometers might be developed, what features affect their behavior most strongly, and how this behavior might be controlled. Those aspects of the Michelson interferometer important to its use as a high resolution spectral device are outlined and expressions relating the physical features of the interferometer and the spectral features of the radiation passing through the instrument, to the form of the observed interference pattern are derived. The sensitivity of the WAMI to misalignments in its optical components is explored, and quantitative estimations of the effects of these misalignments made. A working WAMI with cube corners instead of plane mirrors was constructed and is described. The theoretical notions outlined above are applied to this instrument and found to account for most of its features. A general digital procedure is developed for the analysis of the observed interference fringes which permits an estimation of the amplitude, visibility and phase of the fringes. This instrument was taken to Bird, northern Manitoba as part of the ground based support for the Auroral Rocket and Image Excitation Study (ARIES) rocket campaign. Doppler shifts and linewidth variations in O(^1 D) and O(^1S) emissions in the aurora were observed during several nights and constitute the first synoptic wind measurements taken with a WAMI. The

New developments in NDT through electronic speckle pattern interferometry

International Nuclear Information System (INIS)

Mohan, S.; Murugesan, P; Mas, R.H.

2007-01-01

Full text: Optical holography and speckle interferometry are the emerging optical techniques that can be used for the measurements of microscopic parameters such as displacement, strain, stress and slope. These techniques are applied in various fields such as surface studies, non destructive testing, speckle metrology and steller interferometry. Even though many new NDT methods are available, the suitability for a specific application is based on the material property, nature of defects and sensitivity of detection. Difficulty in radiographic technique is that it fails in detecting tight cracks, planar defects and debonds. Microwave techniques has limited sensitivity for the defect detection and it is not suitable for the objects with metallic cases since the metals are perfect reflectors for the microwaves. Low modulus material attenuates the acoustic energy completely, making ultrasonic testing techniques not feasible. The recently evolved optoelectronic technique namely Electronic Speckle Pattern interferometry (ESPI) is a fast developing optical technique widely used for measuring displacement components, their derivatives, surface roughness, surface contours, shape and others. Due to non contact nature and high sensitivity, this technique has been used as a powerful on line inspection tool for non destructive pattern of materials in industrial environment. The salient feature of ESPI is its capability to display the correlation fringes in a real time on a monitor without the need of photographic processing or optical filtering. ESPI is an alternate non destructive technique suitable for propellant grains and other low modulus materials used in space vehicle systems. The optoelectronic technique can be used to detect cracks, voids and residual stresses etc.., in the components in the industrial environment. In the present investigation, speckle non destructive testing has been carried out on some selected low modulus materials used in space vehicles. The

Systematic comparison between line integrated densities measured with interferometry and polarimetry at JET

International Nuclear Information System (INIS)

Brombin, M.; Zilli, E.; Giudicotti, L.; Boboc, A.; Murari, A.

2009-01-01

A systematic comparison between the line integrated electron density derived from interferometry and polarimetry at JET has been carried out. For the first time the reliability of the measurements of the Cotton-Mouton effect has been analyzed for a wide range of main plasma parameters and the possibility to evaluate the electron density directly from polarimetric data has been studied. The purpose of this work is to recover the interferometric data with the density derived from the measured Cotton-Mouton effect, when the fringe jump phenomena occur. The results show that the difference between the line integrated electron density from interferometry and polarimetry is with one fringe (1.143x10 19 m -2 ) for more than 90% of the cases. It is possible to consider polarimetry as a satisfactory alternative method to interferometry to measure the electron density and it could be used to recover interferometric signal when a fringe jumps occurs, preventing difficulties for the real-time control of many experiments at the JET machine.

A portable magneto-optical trap with prospects for atom interferometry in civil engineering.

Science.gov (United States)

Hinton, A; Perea-Ortiz, M; Winch, J; Briggs, J; Freer, S; Moustoukas, D; Powell-Gill, S; Squire, C; Lamb, A; Rammeloo, C; Stray, B; Voulazeris, G; Zhu, L; Kaushik, A; Lien, Y-H; Niggebaum, A; Rodgers, A; Stabrawa, A; Boddice, D; Plant, S R; Tuckwell, G W; Bongs, K; Metje, N; Holynski, M

2017-08-06

The high precision and scalable technology offered by atom interferometry has the opportunity to profoundly affect gravity surveys, enabling the detection of features of either smaller size or greater depth. While such systems are already starting to enter into the commercial market, significant reductions are required in order to reach the size, weight and power of conventional devices. In this article, the potential for atom interferometry based gravimetry is assessed, suggesting that the key opportunity resides within the development of gravity gradiometry sensors to enable drastic improvements in measurement time. To push forward in realizing more compact systems, techniques have been pursued to realize a highly portable magneto-optical trap system, which represents the core package of an atom interferometry system. This can create clouds of 10 7 atoms within a system package of 20 l and 10 kg, consuming 80 W of power.This article is part of the themed issue 'Quantum technology for the 21st century'. © 2017 The Author(s).

A portable magneto-optical trap with prospects for atom interferometry in civil engineering

Science.gov (United States)

Hinton, A.; Perea-Ortiz, M.; Winch, J.; Briggs, J.; Freer, S.; Moustoukas, D.; Powell-Gill, S.; Squire, C.; Lamb, A.; Rammeloo, C.; Stray, B.; Voulazeris, G.; Zhu, L.; Kaushik, A.; Lien, Y.-H.; Niggebaum, A.; Rodgers, A.; Stabrawa, A.; Boddice, D.; Plant, S. R.; Tuckwell, G. W.; Bongs, K.; Metje, N.; Holynski, M.

2017-06-01

The high precision and scalable technology offered by atom interferometry has the opportunity to profoundly affect gravity surveys, enabling the detection of features of either smaller size or greater depth. While such systems are already starting to enter into the commercial market, significant reductions are required in order to reach the size, weight and power of conventional devices. In this article, the potential for atom interferometry based gravimetry is assessed, suggesting that the key opportunity resides within the development of gravity gradiometry sensors to enable drastic improvements in measurement time. To push forward in realizing more compact systems, techniques have been pursued to realize a highly portable magneto-optical trap system, which represents the core package of an atom interferometry system. This can create clouds of 107 atoms within a system package of 20 l and 10 kg, consuming 80 W of power. This article is part of the themed issue 'Quantum technology for the 21st century'.

Frequency Noise Properties of Lasers for Interferometry in Nanometrology

Directory of Open Access Journals (Sweden)

Ondřej Číp

2013-02-01

Full Text Available In this contribution we focus on laser frequency noise properties and their influence on the interferometric displacement measurements. A setup for measurement of laser frequency noise is proposed and tested together with simultaneous measurement of fluctuations in displacement in the Michelson interferometer. Several laser sources, including traditional He-Ne and solid-state lasers, and their noise properties are evaluated and compared. The contribution of the laser frequency noise to the displacement measurement is discussed in the context of other sources of uncertainty associated with the interferometric setup, such as, mechanics, resolution of analog-to-digital conversion, frequency bandwidth of the detection chain, and variations of the refractive index of air.

Persistent Scatterer Interferometry using Sentinel-1 Data

Science.gov (United States)

Monserrat, Oriol; Crosetto, Michele; Devanthery, Nuria; Cuevas-Gonzalez, Maria; Qihuan, Huang; Barra, Anna; Crippa, Bruno

2016-04-01

This work will be focused on the deformation measurement and monitoring using SAR imagery from the C-band Sentinel-1, a space mission funded by the European Union and carried out by the European Space Agency (ESA) within the Copernicus Programme. The work will firstly address the data processing and analysis procedure implemented by the authors. This includes both Persistent Scatterer Interferometry (PSI) tools to analyse large stacks of SAR images (say, typically more than 20 images), and Differential SAR Interferometry (DInSAR) tools to analyse short SAR image stacks. The work will discuss the characteristics of the main products derived by using Sentinel-1 DInSAR and PSI: deformation maps, deformation velocity maps, deformation time series, residual topographic error, etc. The analysis will be carried out over different types of land use area, e.g. urban, peri-urban and rural areas. The deformation monitoring based on Sentinel-1 data will be compared with the monitoring based on data from pre-existing missions, e.g. C-band ERS and Envisat, X-band TerraSAR-X and CosmoSkyMed, etc. The comparison will concern different study areas, mainly located in Italy and Spain.

Precise signal amplitude retrieval for a non-homogeneous diagnostic beam using complex interferometry approach

Czech Academy of Sciences Publication Activity Database

Krupka, M.; Kálal, M.; Dostál, Jan; Dudžák, Roman; Juha, Libor

2017-01-01

Roč. 12, Aug (2017), s. 1-6, č. článku C08012. ISSN 1748-0221 EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Institutional support: RVO:68378271 Keywords : magnetic-field measurements * fully automated-analysis * laser-produced plasmas * image processing * interferometry * plasma diagnostics - interferometry * spectroscopy and imaging Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.220, year: 2016

Precise signal amplitude retrieval for a non-homogeneous diagnostic beam using complex interferometry approach

Czech Academy of Sciences Publication Activity Database

Krupka, Michal; Kálal, Milan; Dostál, Jan; Dudžák, Roman; Juha, Libor

2017-01-01

Roč. 12, August (2017), č. článku C08012. ISSN 1748-0221. [European Conference on Plasma Diagnostics (ECPD2017)/2./. Bordeaux, 18.04.2017-21.04.2017] R&D Projects: GA MŠk(CZ) LM2015083 Institutional support: RVO:61389021 Keywords : Image processing * Interferometry * Plasma diagnostics - interferometry * Spectroscopy and imaging Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: 2.11 Other engineering and technologies Impact factor: 1.220, year: 2016

Potential of the McMath-Pierce 1.6-Meter Solar Telescope for Speckle Interferometry

Science.gov (United States)

Harshaw, Richard; Jones, Gregory; Wiley, Edward; Boyce, Patrick; Branston, Detrick; Rowe, David; Genet, Russell

2015-09-01

We explored the aiming and tracking accuracy of the McMath-Pierce 1.6 m solar telescope at Kitt Peak National Observatory as part of an investigation of using this telescope for speckle interferometry of close visual double stars. Several slews of various lengths looked for hysteresis in the positioning system (we found none of significance) and concluded that the 1.6 m telescope would make a useful telescope for speckle interferometry.

Kaon versus pion interferometry signatures of quark-gluon plasma formation

International Nuclear Information System (INIS)

Gyulassy, M.; Padula, S.S.

1990-01-01

The advantages of kaon versus pion interferometry as a probe of quark-gluon plasma formation in high energy nuclear collisions are studied by comparing predictions of Lund resonance gas and plasma hydrodynamic models

Theoretical trends in interferometry of ultrarelativistic nuclear collisions

International Nuclear Information System (INIS)

Padula, S.S.

1990-01-01

A review is made of the main concepts of interferometry, since its discovery in the mid 50's as the HBT effect, until recently, where some new approaches to the field were suggested. A few modifications on the correlation function in the case of high energy collisions are discussed and illustrated. (author)

Landau-Zener-Stückelberg Interferometry of a Single Electronic Spin in a Noisy Environment

Directory of Open Access Journals (Sweden)

Pu Huang

2011-08-01

Full Text Available We demonstrate quantum coherent control of single electronic spins in a nitron-vacancy center in diamond by exploiting and implementing the general concept of Landau-Zener-Stückelberg interferometry at room temperature. The interferometry manipulates an effective two-level system of electronic spins which are coupled to the nearby ^{14}N nuclear spin in the nitron-vacancy center as well as the nuclear spin bath in the diamond. With a microwave field to control the energy gap between the two levels and an AC field as the time-dependent driving field in Landau-Zener-Stückelberg interferometry, the interference pattern can be generated and controlled by controlling a number of parameters in the fields, corresponding to coherent control of the state of the electronic spins. In particular, the interference pattern is observed oscillating as a function of the frequency of the microwave field. Decays in the visibility of the interference pattern are also observed and well explained by numerical simulation which takes into account the thermal fluctuations arising from the nuclear bath. Therefore, our work also demonstrates that Landau-Zener-Stückelberg interferometry can be used for probing decoherence processes of electronic spins.

A general circuit model for spintronic devices under electric and magnetic fields

KAUST Repository

Alawein, Meshal

2017-10-25

In this work, we present a circuit model of diffusive spintronic devices capable of capturing the effects of both electric and magnetic fields. Starting from a modified version of the well-established drift-diffusion equations, we derive general equivalent circuit models of semiconducting/metallic nonmagnets and metallic ferromagnets. In contrast to other models that are based on steady-state transport equations which might also neglect certain effects such as thermal fluctuations, spin dissipation in the ferromagnets, and spin precession under magnetic fields, our model incorporates most of the important physics and is based on a time-dependent formulation. An application of our model is shown through simulations of a nonlocal spin-valve under the presence of a magnetic field, where we reproduce experimental results of electrical measurements that demonstrate the phenomena of spin precession and dephasing (“Hanle effect”).

Real-time laser holographic interferometry for aerodynamics

International Nuclear Information System (INIS)

Lee, G.

1987-01-01

Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil pressure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer. 13 references

Phase and fringe order determination in wavelength scanning interferometry.

Science.gov (United States)

Moschetti, Giuseppe; Forbes, Alistair; Leach, Richard K; Jiang, Xiang; O'Connor, Daniel

2016-04-18

A method to obtain unambiguous surface height measurements using wavelength scanning interferometry with an improved repeatability, comparable to that obtainable using phase shifting interferometry, is reported. Rather than determining the conventional fringe frequency-derived z height directly, the method uses the frequency to resolve the fringe order ambiguity, and combine this information with the more accurate and repeatable fringe phase derived z height. A theoretical model to evaluate the method's performance in the presence of additive noise is derived and shown to be in good agreement with experiments. The measurement repeatability is improved by a factor of ten over that achieved when using frequency information alone, reaching the sub-nanometre range. Moreover, the z-axis non-linearity (bleed-through or ripple error) is reduced by a factor of ten. These order of magnitude improvements in measurement performance are demonstrated through a number of practical measurement examples.

Holodiagram: elliptic visualizing interferometry, relativity, and light-in-flight.

Science.gov (United States)

Abramson, Nils H

2014-04-10

In holographic interferometry, there is usually a static distance separating the point of illumination and the point of observation. In Special Relativity, this separation is dynamic and is caused by the velocity of the observer. The corrections needed to compensate for these separations are similar in the two fields. We use the ellipsoids of the holodiagram for measurement and in a graphic way to explain and evaluate optical resolution, gated viewing, radar, holography, three-dimensional interferometry, Special Relativity, and light-in-flight recordings. Lorentz contraction together with time dilation is explained as the result of the eccentricity of the measuring ellipsoid, caused by its velocity. The extremely thin ellipsoid of the very first light appears as a beam aimed directly at the observer, which might explain the wave or ray duality of light and entanglement. Finally, we introduce the concept of ellipsoids of observation.

Parsimonious refraction interferometry

KAUST Repository

Hanafy, Sherif

2016-09-06

We present parsimonious refraction interferometry where a densely populated refraction data set can be obtained from just two shot gathers. The assumptions are that the first arrivals are comprised of head waves and direct waves, and a pair of reciprocal shot gathers is recorded over the line of interest. The refraction traveltimes from these reciprocal shot gathers can be picked and decomposed into O(N2) refraction traveltimes generated by N virtual sources, where N is the number of geophones in the 2D survey. This enormous increase in the number of virtual traveltime picks and associated rays, compared to the 2N traveltimes from the two reciprocal shot gathers, allows for increased model resolution and better condition numbers in the normal equations. Also, a reciprocal survey is far less time consuming than a standard refraction survey with a dense distribution of sources.

Parsimonious refraction interferometry

KAUST Repository

Hanafy, Sherif; Schuster, Gerard T.

2016-01-01

We present parsimonious refraction interferometry where a densely populated refraction data set can be obtained from just two shot gathers. The assumptions are that the first arrivals are comprised of head waves and direct waves, and a pair of reciprocal shot gathers is recorded over the line of interest. The refraction traveltimes from these reciprocal shot gathers can be picked and decomposed into O(N2) refraction traveltimes generated by N virtual sources, where N is the number of geophones in the 2D survey. This enormous increase in the number of virtual traveltime picks and associated rays, compared to the 2N traveltimes from the two reciprocal shot gathers, allows for increased model resolution and better condition numbers in the normal equations. Also, a reciprocal survey is far less time consuming than a standard refraction survey with a dense distribution of sources.

GLINT. Gravitational-wave laser INterferometry triangle

Science.gov (United States)

Aria, Shafa; Azevedo, Rui; Burow, Rick; Cahill, Fiachra; Ducheckova, Lada; Holroyd, Alexa; Huarcaya, Victor; Järvelä, Emilia; Koßagk, Martin; Moeckel, Chris; Rodriguez, Ana; Royer, Fabien; Sypniewski, Richard; Vittori, Edoardo; Yttergren, Madeleine

2017-11-01

When the universe was roughly one billion years old, supermassive black holes (103-106 solar masses) already existed. The occurrence of supermassive black holes on such short time scales are poorly understood in terms of their physical or evolutionary processes. Our current understanding is limited by the lack of observational data due the limits of electromagnetic radiation. Gravitational waves as predicted by the theory of general relativity have provided us with the means to probe deeper into the history of the universe. During the ESA Alpach Summer School of 2015, a group of science and engineering students devised GLINT (Gravitational-wave Laser INterferometry Triangle), a space mission concept capable of measuring gravitational waves emitted by black holes that have formed at the early periods after the big bang. Morespecifically at redshifts of 15 big bang) in the frequency range 0.01 - 1 Hz. GLINT design strain sensitivity of 5× 10^{-24} 1/√ { {Hz}} will theoretically allow the study of early black holes formations as well as merging events and collapses. The laser interferometry, the technology used for measuring gravitational waves, monitors the separation of test masses in free-fall, where a change of separation indicates the passage of a gravitational wave. The test masses will be shielded from disturbing forces in a constellation of three geocentric orbiting satellites.

The Twiss-Hanbury Brown controversy : A 40-years perspective

Energy Technology Data Exchange (ETDEWEB)

Goodman, P.; Langer, W.S.; Brumby, S.P.

1997-12-31

Some key points in the debate over the visible light {sup i}ntensity interferometer{sup ,} initiated by Hanbury Brown and Twiss`s 1956 observation of a positive correlation between two photomultiplier signals from a split-beam optical source, are re-examined. This was a preliminary to their first measurement of a stellar diameter by this means, made in the same year, in the face of great experimental difficulties and criticism of their method, which produced a value for the angular diameter of {alpha}-Sirius which is not only in agreement with present-day measurements, but which provided one of the first tests of quantum electrodynamical theory, and considerably stimulated its further development. We also examine the role which could still be played by {sup i}ntensity interferometry{sup ,} which would be complementary to the programs currently employing Michelson interferometry, by analogy with present-day high-resolution electron microscopy. (authors).