Featured Publications  

Magneto-Optical Garnet Waveguides on Semiconductor Platforms: Magnetics, Mechanics, and Photonics
Sang-Yeob Sung, Anirudh Sharma, Andrew Block, Katherine Keuhn, and Bethanie J. H. Stadler
Garnet films with thicknesses of 100–1000 nm and waveguides with widths of 700–2000 nm were grown onto Si . The polarization and localization of modes near guide surfaces effectively explain the trend in losses versus width. With Faraday rotations of 0.2 dB/ lm and 1.0 dB/mm loss, this integrated garnet has great potential for a multitude of photonic devices, including isolators, circulators, and mode converters. [PDF]

Opening of hybrid bandgaps in two-dimensional photonic crystals of Pb(Mg_1/3Nb_1/3)O₃-PbTiO₃ having very low refractive index contrast
Ratnanjali Khandwal, Xiaoyuan Qi, Sang-Yeob Sung, Bethanie J. H. Stadler, and Yingyin Kevin Zou
The effect of anisotropy on photonic crystals of Pb(Mg_1/3Nb_1/3)O₃-PbTiO₃ rods in air matrices was analyzed. Despite a low refractive index contrast (n=1.47), hybrid photonic bandgaps were achieved after optimization of the structure and the anisotropy. [PDF]

Controlling the angular response of magnetoresistance in Co/Cu multilayered nanowires using Co crystallographic orientation
Liwen Tan, Patrick D. McGary, and Bethanie J.H. Stadler
Ordered nanoporous templates with monodispersed pore diameters were used for the fabrication of multilayered Co/Cu nanowires. The c-axis alignment of Co layers was controlled in order to study the angular variation of the magnetoresistance (ΔMR). When the Co easy axis was in plane (perpendicular to the wire axes), the arrays were magnetically anisotropic and they had a low angular ΔMR (0.08%). This was most likely due to anisotropic magnetoresistance. However, when the Co c axis was out of plane (parallel to wire axes), the arrays were magnetically isotropic but they had larger angular ΔMR (1.33%). The maximum MR was 7% for the whole array. This control of the angular response will be useful in designing sensors for a variety of applications. [PDF]

Integration of magneto-optic garnet waveguides and polarizers for optical isolators
Sang-Yeob Sung, Xiaoyuan Qi, Bethanie J. H. Stadler
YIG waveguides and polarizers were integrated monolithically onto semiconductors. The waveguide losses were 1.55 dB/mm with Faraday rotations of 0.2 dB/mm. Birefringence was minimized by optimized etching. Photonic crystal polarizers and biasing films completed the isolator. [PDF]