Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-25T01:37:07.303Z Has data issue: false hasContentIssue false

Fabrication of Integrated Magneto-Optic Isolator

Published online by Cambridge University Press:  01 February 2011

Sang-Yeob Sung
Affiliation:
Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455
Xiaoyuan Qi
Affiliation:
Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455
John Reinke
Affiliation:
Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455
Samir K. Mondal
Affiliation:
Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455
Sun Sook Lee
Affiliation:
Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455
Bethanie J. H Stadler
Affiliation:
Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455
Get access

Abstract

In optical applications, especially in optical communications, protecting light sources from harmful reflected energy is very important. With magneto-optic isolators, these light sources can be protected to extend their lifetimes and performance by blocking back-reflected light. The active element in these optical isolators is a magneto-optical garnet. However, garnet is difficult to integrate with semiconductors due to the high thermal budget usually required to obtain the garnet crystal structure. For example, current isolator garnets cannot be integrated monolithically into a photonic integrated circuit due to the growth process, liquid phase epitaxy, which requires growth temperatures of >900 °C and also garnet substrates. In this work, magneto-optical garnets were grown monolithically by low-temperature reactive RF sputtering, followed by an ultra-short (<15 sec) anneal. The refractive indices of the resulting garnets were measured using Fourier transform infrared (FTIR) spectroscopy. Various rib waveguides were fabricated by both wet etching and reactive ion etching (RIE). The width of the waveguides varied from 2 to 12 μm and the heights were varied from 0.5 to 1.0 μm. Sm-Co thin films were used for integrated biasing magnets. They were deposited on top of claddings of both magnesium oxide and yttrium oxide, all using the same sputtering system that was used to deposit the garnet films. These magnetic films had high enough remanent fields to saturate the garnet waveguides, and they had coercivities of 700 Oe. The Faraday rotations and waveguide losses of the subsequent isolators were measured to be 10 degrees and 0.1 dB/μm at 632 nm, respectively. Although this prototype is promising, optimization of the device designs is ongoing. In summary, this work succeeded in providing the first comprehensive report on etching YIG by RIE, in developing all of the steps required for integrating isolators on non-garnet substrates, and in proving the feasibility of these isolators.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Mondal, S. and Stadler, B., “Novel designs for integrating YIG/air Photonic Crystal slab polarizers with waveguide Faraday rotators”, IEEE Photo. Tech. Let, in press, Jan. 2005.Google Scholar
[2] Kaewsuriyathumrong, S., Mizumoto, T., Mak, H., and Naito, Y., J. Lightwave Tech., vol. 8, pp. 177182, Feb. 1990.Google Scholar
[3] Levy, M., Ilic, I., Scarmozzino, R., Osgood, R. M. Jr, Wolfe, R., Gutierrez, C. J., and Prinz, G. A., IEEE Photo. Tech. Let., vol. 5, pp 198200, Feb. 1993.Google Scholar
[4] Shintaku, T., Uno, T., and Kobayashi, M., J. Appl. Phys., vol. 74, pp. 48774881, Oct. 1993.Google Scholar
[5] Levy, M., Osgood, R. M. Jr, Hegde, H., Cadieu, F. J., Wolfe, R., and Fratello, V.J., IEEE Photo. Tech. Let., vol. 8, pp. 903906, Jul. 1996.Google Scholar
[6] Bahlmann, N., Chandrasekhara, V., Erdmann, A., Gerhardt, R., Hertel, P., Lehmann, R., Salz, D., Schröteler, F.-J., Wallenhorst, M., and Dötsch, H., J. Lightwave Tech., vol. 16, pp. 818823, May 1998.Google Scholar
[7] Sung, S., Kim, N., and Stadler, B., MRS Symp. – Proc., vol. 768, pp. 111116, 2003.Google Scholar
[8] Sung, S., Qi, X., Mondal, S., and Stadler, B., MRS Symp. – Proc., vol. 817, pp. 213218, 2004.Google Scholar
[9] Suzuki, J. Appl. Phys., vol. 69, pp. 47564760, Apr. 1991.Google Scholar
[10] Gomi, M., Furuyama, H. and Abe, M., J. Appl. Phys., vol. 82, pp. 13591362, Apr. 1997.Google Scholar
[11] Jang, P. and Kim, J., IEEE Trans. Magn., vol. 37, pp. 24382440, Jul. 2001.Google Scholar