Temperature Dependence Of Faraday Rotation Research Articles

Temperature dependence of optical fiber current sensor with external conversion

The paper presents the research of a optical fiber current sensor with external conversion (OFCS-EC) as a function of temperature. The sensor was developed in the Department of Optoelectronics. The sensor was tested in the temperature range from 23 °C – 80 °C. For each of the temperatures, the sensitivity was determined on the basis of a sinusoidal waveform. Thus, the linearity of the transfer characteristics was checked. The main purpose of the experiment was to check the limits of sensitivity changes in changing thermal conditions and whether the sensor meets the standards used in the power industry. Full Text: PDF References M.J. Weber, "CRC Handbook of Laser Science and Technology. Supplement 2: Optical Materials", CRC Press, Boca Raton, FL, USA (1995). CrossRef S. Ju, Y. Lee, Y.T. Ryu, S.G. Kang, J. Kim, P.R. Watekar, B.H. Kim, Y. Lee, Y.H. An, C.J. Kim, W.T. Han, "Temperature Dependence of Faraday Rotation of Glass Optical Fibers Doped with Quantum Dots of CdSe and CdMnTe", Phys. Status Solidi A, 216: 1800549 (2019). CrossRef E. Lage, L. Beran, A.U. Quindeau, L. Ohnoutek, M. Kucera, R. Antos, S. R. Sani, G.F. Dionne, M. Veis, C.A. Ross; Temperature-dependent Faraday rotation and magnetization reorientation in cerium-substituted yttrium iron garnet thin films. APL Mater. 5, 036104 (2017). CrossRef S. Ju, J. Kim, K. Linganna, P.R. Watekar, S.G. Kang, B.H. Kim, S. Boo, Y. Lee, Y.H. An, C.J. Kim, et al. "Temperature and Vibration Dependence of the Faraday Effect of Gd2O3 NPs-Doped Alumino-Silicate Glass Optical Fiber". Sensors, 18, 988 (2018). CrossRef A. Jeffrey, D. and R.M. Bunch, "Temperature dependence of the Faraday rotation of Hoya FR-5 glass," Appl. Opt. 23, 633 (1984). CrossRef K. Barczak, J. Juraszek, "Optoelectronic system for detecting short-circuits in low voltage networks", Photon. Lett. Pol, 14, 37 (2022). CrossRef K. Barczak, K. Mazniewski, "Optical fiber current sensor with external conversion for measurements of low AC electric currents", Proc. SPIE, 10455 (2017). CrossRef

Temperature Dependence of Faraday Rotation of Glass Optical Fibers Doped with Quantum Dots of CdSe and CdMnTe

Specialty optical fibers incorporated with CdSe and CdMnTe quantum dots are fabricated using the modified chemical vapor deposition and high temperature fiber drawing process. Temperature dependence of Faraday rotation angle (FRA) is investigated under magnetic field of 0.126 Tesla (T) upon temperature change from 25 to 120 °C. The FRAs of the CdSe and CdMnTe doped fibers are found to increase linearly with magnetic field and no appreciable change in the FRA of the CdSe doped fiber with the increase of temperature is found regardless of the magnetic field as compared to the CdMnTe doped fiber. Average temperature dependence of the FRA are 16.40 × 10−4 and −104.90 × 10−4 degree °C−1 at 0.126 T for the CdSe and CdMnTe doped fibers and the resultant Verdet constants are estimated to be 3.75 ± 0.04 and 3.50 ± 0.12 rad T−1 m−1, respectively.

Temperature Dependence of Faraday Rotation in Microcavity 1D-MPCs Containing Magneto-Optical Layers with a Compensation Temperature

The low-temperature behavior of optical and magneto-optical properties of microcavity 1D-MPCs with the Bi, Gd, Al-substituted YIG cavity layers of different compositions including compositions with a magnetic compensation temperatures were investigated. The optical transmittance and position of the resonant peaks in optical transmittance and the Faraday rotation spectra were found to be independent of temperature in all types of 1D-MPCs. The temperature dependence of changing the sign of Faraday rotation experienced the hysteresis with a value 8 K in one of two investigated MPCs with magnetic compensation temperature, while in the another MPC the hysteresis did not exceed 1 K. The possible origins of these properties are discussed.

Growth and Characterization of (TbBiGaIG) Film/(TbYbBiIG) Crystal Composite

Bi-substituted rare-earth iron garnet Tb2.40Bi0.60Ga0.13Fe4.87O12 (TbBiGaIG) films on magnetic rare-earth iron garnet Tb0.87Yb1.60Bi0.53Fe5O12 (TbYbBiIG) substrates were grown by a liquid phase epitaxy (LPE) technique. The microstructure and magneto-optical properties of TbBiGaIG film/TbYbBiIG crystal composite were investigated. The (110)-oriented TbBiGaIG single crystal film was epitaxially grown on the TbYbBiIG substrate. The TbBiGaIG film/TbYbBiIG crystal composite showed an improved temperature dependence of Faraday rotation because of the compensation effect.

Compositional Design of Faraday Rotator Materials

AbstractBismuth-doped rare-earth iron garnet thick films have become the material of choice for a wide variety of magnetooptic applications including optical isolators and circulators. Garnet compositional design and liquid phase epitaxial growth have been adapted to the requirements of these devices. Properties such as optical absorption, specific Faraday rotation, temperature dependence of Faraday rotation, saturation magnetization and temperature dependence of saturation magnetization can be controlled to a high degree. Introduction of nucleation induced coercivity has even allowed the elimination of a permanent bias magnet. However, in optimizing device performance and film growth, there are often tradeoffs among these properties. Material design is therefore a compromise based on the requirements of device designers.

Temperature dependence of Faraday rotation and magnetic susceptibility for Ce 3+ and Pr 3+ ions in fluorozirconate glass

The temperature dependencies of the Faraday rotation and magnetic susceptibility for fluorozirconate glass doped with cerium or praseodymium ions are reported. The glass compositions were 52% ZrF 4, 20% BaF 2, 10% CeF 3, 4% AlF 3, and 14% NaF for the cerium-doped glass, and 51% ZrF 4, 21% BaF 2, 8% PrF 3, 4% AlF 3, and 16% NaF for the praseodymium-doped glass; the samples were prepared by quenching from the melt at 1000°C and 960°C for Ce and Pr doped glass, respectively, and annealed at 240°C. Faraday rotations were measured using a modulated optical polarisation technique over a wavelength range of 320–850 nm, and a temperature range of 15–295 K. Magnetic susceptibilities were determined using a transformer-based method over a temperature range of 85–295 K. The paramagnetic part of the Faraday rotation and the magnetic susceptibility both show deviations from Curie's law, and are not simply proportional to each other as frequently assumed. For cerium-doped glass, the temperature dependence of the magnetic susceptibility can be fitted with an expression based on an axially symmetric crystal field appropriate to a square anti-prism site for the cerium ion. The fourth order crystal field parameters are estimated from earlier superposition-model analyses of crystal fields for cerium ions in crystalline fluorides, while the second order parameter is determined by the least squares fitting process.

Optimized Nonreciprocal Rib Waveguides for Integrated Magneto-Optic Isolators

AbstractGarnet films of composition (Lu,Bi)3(Fe,Ga,Al)5O12 and (Tm,Bi)3(Fe,Ga)5O12 are grown by liquid-phase epitaxy on [111]-oriented substrates of gadolinium gallium garnet. Ferrimagnetic films with positive or negative Faraday-rotation as well as paramagnetic films with negligible Faraday-rotation are produced by variations of the rare earth ion substitutions. The temperature dependence of Faraday-rotation is fitted with a molecular field model. Optical rib waveguides in single and double layer garnet films with different Faraday-rotations are realized. The nonreciprocal phase shift of the TM0-Mode is studied both theoretically and experimentally at a wavelength of 1.3 μm. Results show that the maximum nonreciprocal effect at room temperature of double layer films with opposite Faraday-rotation is 1.6 times as large as that of comparable single layer waveguides. But, because of the large temperature dependence of the Faraday-rotation of the positive rotating films, these waveguides show a large temperature dependence of the nonreciprocal phase shift. This problem can be avoided if the positive rotating layer is replaced by a paramagnetic layer. Agreement between calculations and measurements is excellent.

Interionic exchange interaction in A 1−x II MxBVI systems

The superexchange interaction integral JNN is investigated in semimagnetic semiconductors of the type A 1−x II MxBVI systems, where the Mn, Fe, and Co ions are considered as the magnetic component M. Calculations are done in the framework of Racah’s many particle theory including the ground orbital states of the M ions in a cubic crystal. The results of these calculations are compared with published experimental data and with data from a study of the temperature dependence of Faraday rotation. The superexchange mechanism can be used to explain the correlation in the critical values x* at which the interionic interaction becomes important for the Cd1−xMnxTe and Cd1−xFexTe systems.

Anomalies in the temperature dependence of Faraday rotation on yttrium iron garnets doped with Sn, Zr, or Sb

Faraday rotation (FR) measurements on three thin single crystalline samples of yttrium iron garnet doped with Sn, Zr, and Sb as a function of temperature in the near infrared region show a monotonic variation of the magneto-optical signal as the temperature is decreased from 300 to about 50 K. At this point the FR signal levels off. Moreover, the slope of the plot for the sample, doped with Sn, changes sign below this temperature, at particular wavelengths. An explanation of the observed phenomena is given in terms of the energy levels of the Fe2+ ions in the different sites of the crystal and the temperature dependence of their populations caused by the relative orientation between the local symmetry axis of the specific site and the direction of the sample magnetization. Hysteresis loops of the Faraday rotation as a function of applied magnetic field have been also measured showing the presence of a remanence of the sample magnetization.

Faraday effect aid birefringence in orthorhombic Li2Ge7O15 near the ferroelectric phase transition

Abstract The tensor of the Faraday effect and its temperature derivatives were determined from the temperature dependence of Faraday rotation and indices of refraction of orthorhombic Li 2Ge7O15 between 120K and 340K, wave length 633nm. A strong anomaly of the Verdet constant V 33 and of the index n 3 was observed passing through the transition at 284K. The ratio of the slopes of the Verdet constant V 33 above and below the transition is about -2. This value corresponds to a second-order ferroelectric phase transition.

Temperature dependence of Faraday rotation in Bi-substituted terbium iron garnet films

The role of Tb3+ in the Faraday rotation θF of (Bi,Lu)-substituted terbium iron garnet Tb3−x−yLuyBixIG (x=0–1.1, y=0–0.9) films is studied. The temperature dependence of θF at λ=633 nm is measured in the temperature range of 10–600 K and the saturation magnetization 4πMs is measured in the temperature range of 4.2–450 K to clarify the contribution of the dodecahedral Tb3+. The temperature dependence of θF is analyzed by using two different models based on the three sublattice magnetizations. It is found that in the model where the Fe3+ contributions to θF in Bi-substituted iron garnet are assumed to be the same in all rare-earth iron garnets, the contribution of the Tb3+ site to θF is increased by Bi substitution. The variations of the Tb3+ coefficients with Bi content and temperature are also presented and discussed.

DyBi Garnet Films with Improved Temperature Dependence of Faraday Rotation

To improve the temperature dependence of the isolation value of magneto-optical Bi-substituted garnet films for use in optical isolators, the temperature dependence of the Faraday rotation coefficient was measured for (RBi) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> (R = Dy, Gd, Yb) and (GdBi) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (FeAlGa) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> films in the 1.3 and 1.5 μm wavelength bands. Among the various compositions of Bi-substituted garnet films examined, the Dy <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2.5</sub> Bi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> films showed a 2 percent shift in Faraday rotation from that measured at 25°C and an isolation figure of 36 dB in the temperature range from 0 to 50°C. An isolation figure of 29 dB is assured even if the incident light wavelength fluctuates due to the ambient temperature and manufacturing tolerances. These values correspond to those of Y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> bulk single crystals. From the viewpoint of material design, the temperature dependence of the Faraday rotation for Bi-substituted garnets is improved by employing a solid solution with a rare-earth garnet which has a positive Faraday rotation and a negative temperature coefficient of Faraday rotation at room temperature.

DyBi Garnet Films with Improved Temperature Dependence of Faraday Rotation

The effects of host rare-earth ions (Dy, Gd, Yb) on Bi-substituted garnet film Faraday rotation coefficient (θ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</sub> ) variation with temperature were investigated in an effort to improve the isolation of such media used in optical isolators. Even when semiconductor laser wavelength fluctuations (1.310 ± 0.0025 μm) due to environmental temperature change were taken into consideration, observations and calculations showed that in the temperature range 0 to 50°C, the theoretical isolation value for Dy <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2.5</sub> Bi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> can exceed 29 dB. The authors determined that (DyBi) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> epitaxial film Faraday rotation coefficient (-900 deg/cm, 1.3 μm) has low temperature variation when used as isolator material.

IMPROVEMENT OF TEMPERATURE DEPENDENCE OF FARADAY ROTATION USING TWO LAYER EPITAXIAL FILMS IN (BiR)IG FOR OPTICAL ISOLATORS

The temperature dependence of Faraday rotation in the practical temperature range was improved using the two-step-epitaxial method. Two series of compensation films to decrease the temperature dependence of Faraday rotation were attempeted: (1) Tb-garnet films (2) highly Ga-substituted (BiGd)3 (FeGa)5 O12 films. The temperature coefficients of Faraday rotation at 45 degrees (≡ β deg/°C) were measured. In the case of series (2), (BiLuGd)IG/(BiGd)(FeGa)G films with β=0.00 deg/°C were obtained. The total film thickness was 0.58 mm at λ= 1.3 μm, and that was 0.89 mm at λ= 1.55 μm, respectively. The extinction ratio was 38 dB at both wavelengths. In the case of series (1), the Faraday rotation and compensation effect were smaller than those from Crosseley's model. Pb contamination and canting of Tb-sublattice magnetization are plausible causes of the disagreement.

Ｂｉ置換Ｔｂ鉄ガーネット膜におけるファラデー回転係数の温度特性

Temperature dependence of Faraday rotation, which causes degradation of isolation at high or low temperature for an optical isolator, was measured at 1.3 and 0.78 μm wave lengths together with saturation magnetization and optical transparency for epitaxially grown (TbBi)3Fe5O12 films. Temperature dependence of Faraday rotation for these films was smaller than that for (GdBi)3(FeAlGa)5O12 films and (GdBi)3Fe5O12 bulk single crystals. Particularly, Tb2.13Bi0.87Fe5O12 films showed only a 2.1% shift in Faraday rotation from that measured at 25°C in the temperature range 0∼50°C. These values correspond to those of Y3Fe5O12 bulk single crystals. Additionally, (TbBi)3Fe5O12 films had a smaller saturation magnetization than Y3Fe5O12 and sufficient optical transparency in 1.3∼1.5 μm wavelength for an optical isolator.

GROWTH OF Bi-SUBSTITUTED GARNET THICK EPITAXIAL FILMS FOR OPTICAL ISOLATORS

Bi-substituted rare-earth iron garnet thick films have been grown epitaxially as a material for optical isolators. Films with thicknesses in the range of 300-500 microns were obtained without apparent defects using CaMgZr-GGG substrates. In the course of obtaining thick films of good quality, possible mechanisms for crystal defects, lattice mismatch, and bending behavior of the thick film at the growth temperature have been studied. The temperature dependence of Faraday rotation has also been studied with various combinations of rare-earth ions on the c-site. Films of (YbTbBi) 3Fe5O12 show excellent characteristics of the Faraday rotation at the wavelength of 1.3 micron. The rotation is -1800 deg/cm; insertion loss is 0.3 dB; isolation is 42 dB; and the temperature dependence of Faraday rotation is as small as 0.060 deg/K at room temperature. These materials also show good qualities for isolators at the wavelength of 1.55 micron. This technology will lead to the efficient production of the optical isolator used in optical systems.

TEMPERATURE DEPENDENCE OF FARADAY ROTATION FOR Bi-SUBSTITUTED Tb IRON GARNET FILMS

Temperature dependence of Faraday rotation, which causes degradation of isolation at high or low temperature for an optical isolator, was measured at 1.3μm and 0.78μm wavelength together with saturation magnetization and optical transparency for epitaxially grown (TbBi)3Fe5O12 and (TbLaBi)3Fe5O12 films. Temperature dependence of faraday rotation for these films were smaller than those for (GdBi)3(FeAlGa)5O12 films and (GdBi)3Fe5O12 bulk single crystals. Particularly, thick Tb2.2La0.2Bi0.6Fe5O12 films showed less than 0.5% sift in Faraday rotation in the temperature range from 0 to 50°C. Additionally Tb2.2La0.2Bi0.6Fe5O12 films had a small saturation magnetization, compared with Y3Fe5O12 and sufficient optical transparency in 1.3∼1.5μm wavelength for an optical isolator.

SEM Analysis and Temperature Dependence of Faraday Rotation in Bi-Substituted Magnetic Garnets

SEM analysis was used to investigate the crystal defects affecting the magneto-optical figure of merit and the reverse insertion loss of these single crystals, and the temperature variation of the Faraday rotation coefficient was also measured. The defect analyses showed that Bi itself is more prevalent among the defects than Bi-substituted garnet single crystal composition, and Fe and Gd are low. This seems to be due to the fact that the composition of the solvent used during crystal growth is not uniform. The Faraday rotation coefficient θF at a wavelength of 0.78 μm in the temperature range from room temperature to 100°C was found to be approximately -0.15%/°C.

ＤｙによるＢｉ置換ガーネット膜のファラデー回転角温度特性の改良

To improve temperature dependence of the isolation value of magneto-optic Bi-substituted garnet films for use in an optical isolator, temperature dependence of Farady rotation coefficient was measured for (RBi)3Fe5O12(R=Dy, Gd, Yb) and (GdBi)3(FeAlGa)5O12 films in 1.3 and 1.5 μm wavelength bands. Among the Bi-substituted garnet films with various composition examined, Dy2.5Bi0.5Fe5O12 films showed a 2% shift in Faraday rotation from that measured at 25°C and assured isolation of 36 dB in the temperature range of 0-50°C. Isolation of 29 dB is assured, even if incident light wavelength fluctuates due to ambient temperature and manufacturing lot. These values correspond to those of Y3Fe5O12 bulk single crystal. From the viewpoint of material designing, temperature dependence of Faraday rotation for Bisubstituted garnets is improved by employing a solidsolution with the rare-earth garnet which has a positive Faraday rotation with negative temperature coefficient of Faraday rotation at room temperature.

Landau levels and interband Faraday rotation in mixed semiconductors containing paramagnetic atoms

Effect of the exchange interaction between spin of the mobile carriers and that of localized paramagnetic atoms on the magnetic levels energetic structure is studied in the wide gap semiconductors. Calculation shows that this interaction is responsible for a very profound temperature dependence of Faraday rotation as recently observed in Cd 1− x Mn x Te.