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Crystals Miguel Levy, Michigan Technological University, DMR 0709669 This project focuses on the development of new magnetic materials with strong nonlinear magnetic susceptibility. A total of 43 bismuth-substituted iron garnet (Bi,Y) 3-x (Fe,Ga) 5-y O 12 (Bi:YIG) films were sputter- deposited and characterized for crystalline structure, composition and nonlinear response. It was found that in unannealed Bi:YIG films lattice mismatch strain drives the second harmonic (SH) signal, while in annealed films micro- strain controls the SH signal in the absence of an external magnetic field. Hyper-Rayleigh scattering measurements showed that oriented crystallites produce strong non-diffusive SH generation. A sought-for magnetization dependence of the (a) Strong SH signal dependence on lattice mismatch strain for un-annealed samples. (b) SH signal shows dependence on micro- strain in annealed samples. (c) HRS indicatrix of a film shows sharp non- diffusive SH contribution from oriented crystallites, (d) Magnetic contrast study evincing that the SH signal depends strongly on magnetic field direction (a) 0 100 200 300 400 500 1 2 3 1 3 S a m p le , 6 0m W PP S ig n a l, a .u. T im e , se c 100 200 300 400 500 0 1 2 3 S.H. Signal (a.u.) Time (sec.) (d) 60 mW PP geometry Dubrovina, Kumar, Levy, Maydykovskiy, Aktsipetrov, Moscow Intern. Symp. on Magn. (MISM 2011) (b) (c)
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Materials World Network: Nonlinear Magneto-Photonic Crystals Miguel Levy, Michigan Technological University, DMR 0709669. (a). (b). 3. (d). (c). 2. S.H. Signal (a.u.). 1. 100. 0. 200. 300. 400. 500. Time (sec.). - PowerPoint PPT Presentation
Transcript of (a)
Materials World Network: Nonlinear Magneto-Photonic CrystalsMiguel Levy, Michigan Technological University, DMR 0709669
This project focuses on the development of new magnetic materials with strong nonlinear magnetic susceptibility. A total of 43 bismuth-substituted iron garnet (Bi,Y)3-x(Fe,Ga)5-yO12 (Bi:YIG) films were sputter-deposited and characterized for crystalline structure, composition and nonlinear response. It was found that in unannealed Bi:YIG films lattice mismatch strain drives the second harmonic (SH) signal, while in annealed films micro-strain controls the SH signal in the absence of an external magnetic field. Hyper-Rayleigh scattering measurements showed that oriented crystallites produce strong non-diffusive SH generation. A sought-for magnetization dependence of the SH signal was achieved, evidenced as signal strength jumps upon field reversal. An optical set-up was assembled for the optical parametric amplification and waveguide confinement study of the SH signal in planar magneto-photonic crystals.
(a) Strong SH signal dependence on lattice mismatch strain for un-annealed samples. (b) SH signal shows dependence on micro-strain in annealed samples. (c) HRS indicatrix of a film shows sharp non-diffusive SH contribution from oriented crystallites, (d) Magnetic contrast study evincing that the SH signal depends strongly on magnetic field direction (shown by arrows).
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Dubrovina, Kumar, Levy, Maydykovskiy, Aktsipetrov, Moscow Intern. Symp. on Magn. (MISM 2011)
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High school student testing the confining of light in a water stream during 2011 Summer Youth Program activity for the MTU Engineering Scholars Program organized by this NSF project. Graduate students Pradeep Kumar and Jacob Ruben led the activity involving about 120 students, mostly from Lower Michigan, approximately 40% underrepresented minority.
International research collaboration continues with the group of Professor Aktsipetrov at Moscow State University. Bi:YIG samples sputter-deposited and characterized at Michigan Tech have been tested in Moscow for nonlinear response. Scientific discussions are ongoing. Work based on this project has been presented at the Moscow International Symposium on Magnetism (MISM) held in Moscow in August 2011
High school student testing total internal reflection with a water stream. Below: Partial view of student participants in 2011 Summer Youth activity organized by this NSF project.
Materials World Network: Nonlinear Magnetophotonic CrystalsMiguel Levy, Michigan Technological University, DMR 0709669
