Journal ArticleDOI
Refractive index and dispersion of the Europium-Chalcogenides
P. Wachter
- Vol. 8, Iss: 1, pp 80-86
TLDR
In this paper, the authors measured the refractive index of Europium-Chalcogenides as a function of wavelength, temperature and magnetic field and compared with dispersion theory.Abstract:
The refractive index of the Europium-Chalcogenides has been measured as a function of wavelength, temperature and magnetic field and compared with dispersion theory. The refractive index increases from EuO to EuTe and with decreasing temperature. Attributing different oscillator strengths to the various substances, classical dispersion theory can account for the observed changes in the refractive index. The optical and static dielectric constant, the Reststrahlen wavelength and the compressibility have been computed.read more
Citations
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Journal ArticleDOI
Linear optical birefringence of magnetic crystals
J Ferre,G A Gehring +1 more
TL;DR: The study of changes in the refractive indices (with consequent changes of birefringence) of a transparent magnetic crystal which accompany changes in magnetic order is becoming more popular as mentioned in this paper.
Journal ArticleDOI
Compact optical one-way waveguide isolators for photonic-band-gap microchips
Hiroyuki Takeda,Sajeev John +1 more
Abstract: In two-dimensional (2D) photonic crystals (PC's), we demonstrate compact optical waveguide isolators in which light can propagate only one way. Waveguides are composed of magneto-optical materials with magnetic domain walls. Magneto-optical effects and magnetic domain walls break time-reversal and space-inversion symmetries, respectively, leading to nonreciprocal waveguides with different group velocities for forward and backward propagating light of a given frequency. When backward light has a zero group velocity, only forward light can be transmitted while backward light stops. Slow leakage of backward light (when the group velocity is not precisely zero) is eliminated by introducing absorption loss in nonreciprocal PC waveguides. Then, absorption of forward light is less than that of backward light. Introducing gain material and signal amplification by current injection, forward light can propagate with no net loss and only backward light is attenuated. We demonstrate that backward light, with nearly zero group velocity, can be eliminated because of absorption over a long effective optical path length. This enables compact on-chip photonic band-gap isolators. The waveguide isolator is assumed to be composed of europium oxide with the Faraday rotation angle of ${\ensuremath{\theta}}_{F}=3.49\ifmmode\times\else\texttimes\fi{}{10}^{3}\phantom{\rule{0.3em}{0ex}}\mathrm{rad}∕\mathrm{cm}$ at wavelength $\ensuremath{\lambda}=1.5\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$ under a magnetic field $0.9\phantom{\rule{0.3em}{0ex}}\text{Tesla}$. In a waveguide isolator with the length of $8.5\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$, transmittance of backward light is mostly zero at a specific frequency when transmittance of forward light is amplified to 1 by current injection. The usable bandwidth is up to $12\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ centered at $1.5\phantom{\rule{0.3em}{0ex}}\text{micron}$ wavelength as the device length is increased $(L=42.6\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m})$. We demonstrate similar results for an asymmetric nonreciprocal waveguide without a magnetic domain wall. The possibility of compact on-chip photonic band-gap isolators is demonstrated for 2D membrane photonic crystals with finite thickness in the third dimension. Computations are performed using plane wave expansion, finite difference time domain, and optical Wannier function methods.
Journal ArticleDOI
Optical properties and electronic structure of europium chalcogenides
TL;DR: In this paper, the normal incidence reflectivity of europium chalcogenide single crystals and of Gd doped EuO has been measured at room temperature in the spectral region from 250 μm to 12 eV and has been analyzed in terms of the optical constants.
Journal ArticleDOI
Energy level scheme and the effect of magnetic order on the optical transitions in europium chalcogenides
TL;DR: The optical constants of Eu-chalcogenide single crystals have been determined at room temperature for photon energies from 1 to 6 eV as discussed by the authors, and the transmission of thin evaporated films (except for EuO) has been measured with polarized light above and below the magnetic ordering temperature.
Journal ArticleDOI
Structure and Properties of Orthoborate Glasses in the Eu2O3–(Sr,Eu)O–B2O3 Quaternary
A. Winterstein-Beckmann,Doris Möncke,Dimitrios Palles,Efstratios I. Kamitsos,Lothar Wondraczek +4 more
TL;DR: The structure and properties of melt-quenched glasses and partially crystallized samples from the borate series (1-2x)Eu2O3-x((Eu,Sr)O-B2 O3) were investigated using Raman, infrared, electron spin resonance, and UV-vis absorption and fluorescence spectroscopic techniques, confirming previous findings on manganese-strontium borates with high modification levels.
References
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Journal ArticleDOI
Optical Properties of Semiconductors
H. R. Philipp,H. Ehrenreich +1 more
TL;DR: In this article, the real and imaginary parts of the dielectric constant and the function describing the energy loss of fast electrons traversing the materials are deduced from the Kramers-Kronig relations.
Journal ArticleDOI
Compressibility and absorption frequency of ionic crystals
TL;DR: In this paper, a simple relation is derived between the compressibility and absorption frequency of ionic crystals, taking into account the change which a displacement induces in the electronic configuration, and is independent of the uncertainty concerning the Lorentz force.
Journal ArticleDOI
Optical absorption of ferro- and antiferromagnetic europium chalcogenides
G. Busch,P. Junod,P. Wachter +2 more
Journal ArticleDOI
Magnetic and Structural Properties of Europium Metal and Europium Monoxide at High Pressure
TL;DR: In this paper, the change of the Curie temperature of EuO with pressure has been measured up to 90 kbar by resistivity and initial-permeability methods, respectively.
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