Optimized Nonreciprocal Rib Waveguides for Integrated Magneto-Optic Isolators

1998 ◽  
Vol 517 ◽  
Author(s):  
M. Wallenhorst ◽  
V. Backherms ◽  
A. Josef ◽  
N. Bahlmann ◽  
M. Lohmeyer ◽  
...  
Keyword(s):  
Phase Shift ◽  
Temperature Dependence ◽  
Double Layer ◽  
Faraday Rotation ◽  
Single Layer ◽  
Large Temperature ◽  
Gadolinium Gallium Garnet ◽  
Rare Earth Ion ◽  
Garnet Films ◽  
Rib Waveguides

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.

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

1988 ◽  
Vol 63 (8) ◽  
pp. 3113-3115 ◽  
Author(s):  
H. Umezawa ◽  
Y. Yokoyama ◽  
N. Koshizuka
Keyword(s):  
Temperature Dependence ◽  
Faraday Rotation ◽  
Garnet Films ◽  
Iron Garnet

Micromorphology, Microstructure and Magnetic Properties of Sputtered Garnet Multilayers

1997 ◽  
Vol 494 ◽  
Author(s):  
R. Marcelli ◽  
G. Padeletti ◽  
N. Gambacorti ◽  
M. G. Simeone ◽  
D. Fiorani
Keyword(s):  
Magnetic Properties ◽  
Single Layer ◽  
Microstructural Characterization ◽  
Magnetic Multilayers ◽  
Gadolinium Gallium Garnet ◽  
Magnetic Clusters ◽  
Garnet Films ◽  
Secondary Ions ◽  
Paramagnetic Behaviour ◽  
Iron Garnet

ABSTRACTThe growth technique, the micromorphological and microstructural characterization by means of atomic force microscopy (AFM) and secondary ions mass spectrometry (SIMS) as well as the magnetic properties of a novel class of magnetic multilayers, based on radio frequency (RF) sputtered thin amorphous garnet films, are presented. One, three and five thin film multilayers composed by amorphous pure yttrium iron garnet (a:YIG) and amorphous gadolinium gallium garnet (a:GGG) have been grown on GGG single crystal substrates. The multilayer interfaces have been found to be comparable in both, the three and five-layers structure. Low field susceptibility measurements, showed a paramagnetic behaviour for the single layer YIG film. For the three and five layers samples, irreversibility effects were observed, giving evidence of magnetic clusters at the interface YIG/GGG.

Enhanced Faraday rotation in garnet films and multilayers

2004 ◽  
Vol 817 ◽  
Author(s):  
S. Kahl ◽  
A. M. Grishin
Keyword(s):  
Faraday Rotation ◽  
Layer Structure ◽  
Single Layer ◽  
Optical Transmittance ◽  
Defect Layer ◽  
Equivalent Thickness ◽  
One Dimensional ◽  
Garnet Films ◽  
Optical Visualization ◽  
Film Substrate

AbstractFilms were prepared by pulsed laser deposition. We investigated or measured crystallinity, morphology, film-substrate interface, cracks, roughness, composition, magnetic coercivity, refractive index and extinction coefficient, and magneto-optical Faraday rotation (FR) and ellipticity. The investigations were partly performed on selected samples, and partly on two series of films on different substrates and of different thicknesses. BIG films were successfully tested for the application of magneto-optical visualization. The effect of annealing in oxygen atmosphere was also investigated - very careful annealing can increase FR by up to 20%.Periodical BIG-YIG multilayers with up to 25 single layers were designed and prepared with the purpose to enhance FR at a selected wavelength. A central BIG layer was introduced as defect layer into this one-dimensional magneto-optical photonic crystal (MOPC) and generated resonances in optical transmittance and FR at a chosen design wavelength. In a 17-layer structure, at the wavelength of 748 nm, FR was increased from–2.6 deg/μm to –6.3 deg/μm at a small reduction in transmittance from 69% to 58% as compared to a single-layer BIG film of equivalent thickness. In contrast to thick BIG films, the MOPCs did not crack. We were first to report preparation of all-garnet MOPCs and second to experimentally demonstrate the MOPC principle in magneto-optical garnets.

scholarly journals Manifestations of the effects of a “weak” sublattice in an YIG film with the replacement of yttrium by Gd ions

2018 ◽  
Vol 185 ◽  
pp. 02011
Author(s):  
Vladislav Poimanov ◽  
Vladiimir Shkar ◽  
Yuriy Nepochatykh ◽  
Vedamanickam Sampath ◽  
Vladiimir Shavrov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Temperature Dependence ◽  
Resonance Method ◽  
Ferromagnetic Material ◽  
Gadolinium Gallium Garnet ◽  
Exchange Field ◽  
Ferrite Garnet ◽  
Garnet Films ◽  
Magnetic Sublattice

Ferrite-garnet films of submicron thickness were investigated by ferromagnetic resonance method and by the autodyne oscillator method. Compensation of the magnetization of such a film is detected on the curve of its temperature dependence, which is associated with the inclusion of gadolinium ions from the gadolinium-gallium garnet substrate in its composition. It was found that the magnetization of the sample in perpendicular to the surface of the film magnetic field showed an abnormal change in the magnetization and also rotation of the magnetic axis. This behaviour of a ferromagnetic material in the presence of a magnetic field can be explained by the expressions for the linear magnetostrictive effect, and the piezomagnetic effect arising from the para-processes operating within a “weak” rare-earth magnetic sublattice which is located inside a unidirectional exchange field of “strong” iron sublattice.

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