- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Crystallization of bismuth iron garnet thin films using capacitively coupled oxygen plasmas
摘要： It is demonstrated for the first time that amorphous bismuth iron garnet films can be crystallized within capacitively coupled oxygen plasmas at temperatures approximately 100 °C lower than required using conventional thermal annealing. We characterize the plasma optical emissions at high pressures (2 Torr–5 Torr) and high rf powers (500 W–800 W) and show that film crystallization is nevertheless related to thermal conditions generated in the plasma. It is demonstrated that these thermal conditions are related to the concentration of the dominant oxygen species O and O+ in the plasma, which, in turn, are a function of the rf power and pressure. The plasma treated garnet Faraday rotation and optical transmission are shown to be comparable with conventional oven or rapid thermal annealing.
关键词： capacitively coupled oxygen plasmas,thin films,bismuth iron garnet,Faraday rotation,crystallization
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Epitaxial GaP grown on Silicon by MEE and MBE Techniques as a Pathway for Dilute Nitride-Si Tandem Solar Cells
摘要： For long-wavelength space-based radars, such as the P-band radar on the recently selected European Space Agency BIOMASS mission, system distortions (crosstalk and channel imbalance), Faraday rotation, and system noise all combine to degrade the measurements. A first-order analysis of these effects on the measurements of the polarimetric scattering matrix is used to derive differentiable expressions for the errors in the polarimetric backscattering coefficients in the presence of Faraday rotation. Both the amplitudes and phases of the distortion terms are shown to be important in determining the errors and their maximum values. Exact simulations confirm the accuracy and predictions of the first-order analysis. Under an assumed power-law relation between σhv and the biomass, the system distortions and noise are converted into biomass estimation errors, and it is shown that the magnitude of the deviation of the channel imbalance from unity must be 4–5 dB less than the crosstalk, or it will dominate the error in the biomass. For uncalibrated data and midrange values of biomass, the crosstalk must be less than ?24 dB if the maximum possible error in the biomass is to be within 20% of its true value. A less stringent condition applies if the amplitudes and phases of the distortion terms are considered random since errors near the maximum possible are very unlikely. For lower values of the biomass, the noise becomes increasingly important because the σhv signal-to-noise ratio is smaller.
关键词： Biomass,Faraday rotation,polarimetric measurements,system distortion,calibration,long-wavelength radar
更新于2025-09-19 17:13:59
-
[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Enhanced Magneto-Optical Effects in Magnetic Photonic Crystal Fiber Based on Yttrium Iron Garnet
摘要： In this paper, a kind of magnetic photonic crystal fiber of Yttrium iron garnet (YIG) is presented. The influence of gyrotropy on TE-TM mode conversion is analysed, which depends on Faraday rotation. The structure parameters are simulated and optimized. The optimum efficiency of 93.57% is obtained. Faraday rotation and modal birefringence have been calculated by varying gyrotropy from 0.01 to 0.04. The numerical results reveal an increased Faraday rotation and a reduced modal birefringence of 10-5. The enhanced properties of the structure could improve photonic devices performance, which make it suitable for magneto-optical isolators.
关键词： Modal birefringence,Faraday rotation,YIG,Magnetic photonic crystal fiber,Mode conversion
更新于2025-09-16 10:30:52
-
Bi substituted YIG ceramics isolator for optical communication
摘要： We have succeeded in synthesizing transparent (BixY3-x)Fe5O12 [x ? 0e1.1] ceramics by reactive sintering method for the ?rst time in the world. The transmission spectrum of Bi-doped YIG showed character-istics comparable to the Bi:Gd3Fe5O12 single crystal produced by LPE method. The obtained Bi:YIG ceramic was uniformly composed of grains around below 5 mm. Residual pores, secondary phases and grain boundary phases were not detected. The distribution of Bi, Y, and Fe in this material was extremely uniform for up to x ? 0.4, but a rather high concentration of Bi at grain boundaries was detected by HR-TEM-EDS analysis for x ? 0.8. The Faraday rotation angle linearly increased with the Bi content, and the Faraday rotation angle per atomic % of Bi was (cid:2)31.2 deg./cm at 1550 nm, and this value was similar to the (Bi1.1Gd1.9)Fe5O12 single crystal produced by LPE method. In addition to LPE method which requires a seed substrate (Gd3Ga5O12) and a steep temperature gradient, it was demonstrated in this work that Bi-doped iron garnet can be synthesized by solid-state reactive sintering method, and also con?rmed that the magneto-optical performance of the polycrystalline Bi:YIG ceramics was equivalent to single crystal.
关键词： Isolator,YIG ceramics,Bi-substituted,Faraday rotation,Transparent
更新于2025-09-16 10:30:52
-
Enhanced Resonant Faraday Rotation in Multilayer Magnetoplasmonic Nanohole Arrays and Their Sensing Application
摘要： The optical and magneto-plasmonic properties of Ag/Co and Ag/Co/Ag multilayer nano-hole arrays have been investigated. By including a top- and bottom-Ag plasmonic layer onto a Co ferromagnetic perforated film, strong extraordinary optical transmission peaks and Wood’s anomalies (transmission minima) at both film-air and film-glass interfaces of the film are observed. The coupling between plasmonics and magneto-optics in the arrays gives rise to several resonantly enhanced Faraday rotation peaks that are much sharper than the plasmonic peaks/dips. The rotation peaks appeared exactly at the transmission minima have widths as narrow as 13 nm, which are much narrower than the transmission peaks (> 100 nm) and the accompanying transmission dips (~ 52 nm). The narrow line width of this enhanced Faraday rotation peak allows at least 2 times enhancement of the sensing performance, which is characterized by figure of merit, in compare to any other features of the optical transmission spectra.
关键词： Magnetic,Nano-Hole Arrays,Sensing Application,Hybrid Materials,Plasmonics,Magneto-Plasmonic,Faraday Rotation,Optical
更新于2025-09-12 10:27:22
-
Faraday Effect and Magnetic Circular Dichroism in Media with Magneto-Plasmonic Nanoparticles and Two-Particle Clusters
摘要： The Faraday rotation and magnetic circular dichroism (MCD) in media containing spherical layered nanoparticles with a ferromagnetic core and a plasmon shell or two-particle clusters consisting of ferromagnetic and plasmonic nanoparticles are studied theoretically. Optical absorption spectra, MCD spectra, the orientation angle of the polarization ellipse, and the ellipticity of the light wave are calculated for these systems in the quasistatic approximation of electrodynamics. It is shown that the magneto-optical response of media with magneto-plasmon inclusions depends on the size of the ferromagnetic component of the inclusion. Moreover, this dependence is more pronounced for layered particles, and the response in the region of plasmon resonance of the noble metal is greater than for two-particle clusters.
关键词： magnetic circular dichroism,Faraday rotation,two-particle cluster,magneto-optical phenomena,magneto-plasmonic nanoparticle,dipole dynamic polarizability
更新于2025-09-12 10:27:22
-
Wide-band enhancement of the transverse magneto-optical Kerr effect in magnetite-based plasmonic crystals
摘要： The transverse magneto-optical Kerr effect (TMOKE) in magnetite-based magnetoplasmonic crystals is studied experimentally and theoretically. We analyze angle-resolved TMOKE spectra from two types of structures where noble metallic stripes are incorporated inside a thin magnetite film or located on top of a homogeneous film. A multiple-wide-band enhancement of the TMOKE signal in transmission is demonstrated. The complex dielectric permittivity and gyration are experimentally determined using the ellipsometry technique as well as Faraday rotation and ellipticity measurements. The obtained parameters are used in rigorous coupled-wave analysis (RCWA) calculations for studying the optical resonances. Our RCWA calculations of transmittance and TMOKE are in good agreement with the experimental data. The role of guiding and plasmonic modes in the TMOKE enhancement is revealed. We demonstrate that the TMOKE provides rich information about the studied optical resonances.
关键词： transverse magneto-optical Kerr effect,ellipticity measurements,gyration,magnetoplasmonic crystals,Faraday rotation,dielectric permittivity,optical resonances,RCWA,magnetite,TMOKE
更新于2025-09-12 10:27:22
-
Optical current, momentum and angular momentum in anisotropic materials exposed to detailed balance
摘要： This work investigates the theory behind a thought experiment that intends to measure momentum and angular momentum of matter exposed to “isotropic radiative noise”. Radiative momentum has been a controversial subject for decades. The radiative momentum of isotropic noise is intuitively expected to be zero. We formulate the general features of the isotropic noise such as equipartition of energy and the vanishing of integrated Poynting vector. We demonstrate that in bi-anisotropic materials, a ?nite radiative momentum persists that performs work on the matter when its parameters change slowly. We ?nd that Faraday rotation in the scattering of the radiative noise induces an angular momentum along the applied external magnetic ?eld. Also, the Poynting vector is found to circulate around the matter, raising the question whether it really describes the energy ?ow. These e?ects are small and hard to measure in any real experiment. Yet, they are surprising predictions of the classical, macroscopic Maxwell equations, and make contact with the outcome of recent QED calculations done for the quantum vacuum.
关键词： isotropic radiative noise,Maxwell equations,Faraday rotation,QED calculations,Poynting vector,bi-anisotropic materials,radiative momentum
更新于2025-09-11 14:15:04
-
Influence of Substrate Stage Temperature and Rotation Rate on the Magneto-Optical Quality of RF-Sputtered Bi2.1Dy0.9Fe3.9Ga1.1O12 Garnet Thin Films
摘要： Highly bismuth-substituted iron garnet thin films are prepared on quartz substrates by using a radio frequency (RF) magnetron sputtering technique. We study the factors (process parameters associated with the RF magnetron sputter deposition technique) affecting the magneto-optical (MO) properties of ferrite garnet films of composition Bi2.1Dy0.9Fe3.9Ga1.1O12. All ?lms show high MO response across the visible range of wavelengths after being annealed. In particular, the effects of substrate stage temperature and rotation rate on the various properties of ?lms are studied. Experimental results reveal that the characteristics of garnet ?lms of this type can be tuned and optimized for use in various magnetic ?eld-driven nanophotonics and integrated optics devices, and that, at a substrate stage rotation rate near 16 revolutions per minute, the MO quality of the developed MO ?lms is the best, in comparison with ?lms deposited at other rotation rates. To the best of our knowledge, this is the ?rst report on the effects of deposition parameters on the properties of garnet ?lms of this stoichiometry.
关键词： magneto-photonics,Faraday rotation,MO garnets,substrate temperature,process parameters,RF magnetron sputtering
更新于2025-09-10 09:29:36
-
Polarization-Sensitive Fourier-Transform Spectroscopy of HgTe/CdHgTe Quantum Wells in the Far Infrared Range in a Magnetic Field
摘要： Spectra of magnetoabsorption and Faraday rotation in HgTe/CdHgTe heterostructures with single and double quantum wells in high magnetic fields up to 11 T have been studied by the Fourier-transform spectroscopy method. The study of Faraday rotation spectra makes it possible to determine the sign of resonance circular polarization of transitions between Landau levels of carriers, which allows identifying observed intraband and interband transitions in the far and middle infrared ranges.
关键词： Faraday rotation,Landau levels,magnetoabsorption,Fourier-transform spectroscopy,HgTe/CdHgTe quantum wells
更新于2025-09-10 09:29:36