Hostname: page-component-7c8c6479df-xxrs7 Total loading time: 0 Render date: 2024-03-28T21:54:03.587Z Has data issue: false hasContentIssue false

Optical Losses in Ferroelectric Oxide Thin Films: Is There Light at the End of the Tunnel?

Published online by Cambridge University Press:  15 February 2011

D. K. Fork
Affiliation:
Xerox Palo Alto Research Center, Palo Alto, CA 94304, USA
F. Armani-Leplingard
Affiliation:
Xerox Palo Alto Research Center, Palo Alto, CA 94304, USA
J. J. Kingston
Affiliation:
Xerox Palo Alto Research Center, Palo Alto, CA 94304, USA
Get access

Abstract

Optical losses are a barrier to use of ferroelectric waveguide thin films. Losses of about 2 dB/cm will reduce the efficiency of a frequency doubler by over 50%. Achieving losses on this order in conjunction with other essential film properties is difficult. The optical loss has several origins, including absorption, mode leakage, internal scattering and surface scattering. When the film surface morphology is accurately known, it is possible to estimate the surface scattering component of the loss. We have employed atomic force microscopy and computer modeling to compute, and correlate the optical loss as a function of film thickness and wavelength. The results suggest upper limits to the morphological roughness for various device applications. For lithium niobate films on sapphire which are intended to frequency double into the blue part of the spectrum, the optimal film thickness is about 400 nm and the RMS roughness is constrained below about 1.0 nm, with some weak dependence on grain size. Although present growth techniques do not appear to achieve this level of surface flatness intrinsically, an understanding of the morphological development of the film structure may lead to improvements.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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 Lipscomb, G. F., Lytel, R. S., Ticknor, A. J., Kenny, J., Van Eck, T. E., Girton, D. G., and Binkley, E., Proc. Mater. Res. Soc. Symp., 228, 15 (1992).Google Scholar
2 Risk, W. P., Optics and Photonics News, 1(5), 10 (1990).Google Scholar
3 Nashimoto, K., Fork, D. K., and Geballe, T. H., Appl. Phys. Lett., 60, 1199 (1992).Google Scholar
4 Hsu, W-Y., and Raj, R., Appl. Phys. Lett., 60, 3105 (1992).Google Scholar
5 Fork, D. K. and Anderson, G. B., Appl. Phys. Lett. 63, 1029 (1993).Google Scholar
6 Hung, L. S., Agostinelli, J. A., Mir, J. M., and Zheng, L. R., Appl. Phys. Lett., 62, 3071 (1993).Google Scholar
7 Gutmann, R., Huliger, J., Hauert, R., and Moser, E. M., J. Appl. Phys., 70, 2648 (1991).Google Scholar
8 Nishihara, H., Haruna, M. and Suhara, T., Optical Integrated Circuits, p. 167168, McGraw Hill Optical and Electro-optical engineering series, New York 1989.Google Scholar
9 Schwyn Thony, S., Lehman, H. W., and Gunter, P., Appl. Phys. Lett., 61, 373 (1992).Google Scholar
10 Graettinger, T. M., Rou, S. H., Ameen, M. S., Auciello, O., and Kingon, A. I., Appl. Phys. Lett., 58, 1964 (1991).Google Scholar
11 Kingston, J. J., Fork, D. K., Leplingard, F., Ponce, F. A., Mat. Res. Soc. Symp. Proc., 341, 289 (1994).Google Scholar
12 Marcuse, D., Theory of Dielectric Optical Waveguides, (Academic Press, New York, 1974), Chap. 3.Google Scholar
13 Marcuse, D., Bell Sys. Tech. J., p. 3187, Dec. 1969.Google Scholar
14 pseudo-even and pseudo-odd designate modes which are truly odd or even in the limit of a symmetric slab guide.Google Scholar
15 Fork, D. K., Armani-Leplingard, F., and Kingston, J. J., proceedings of the 6th International Symposium on Integrated Ferroelectrics, vol. 6, part 1, March 1994, Monterey CA.Google Scholar