Phys. Rev. Lett. Phys. Rev. A Phys. Rev. B Phys. Rev. C Phys. Rev. D Phys. Rev. E Phys. Rev. ST AB Phys. Rev. ST AB Rev. Mod. Phys. Phys. Rev. (Series I) Phys. Rev. Volume: Page/Article:

Phys. Rev. Lett. 71, 537–540 (1993)

[Issue 4 – 26 July 1993 ]

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X-ray flux enhancement in thin-film waveguides using resonant beam couplers

Y. P. Feng, S. K. Sinha, H. W. Deckman, J. B. Hastings, and D. P. Siddons

Exxon Research and Engineering Company, Annandale, New Jersey 08801

National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973

We present experimental evidence for achieving significant x-ray flux enhancement by coupling a highly collimated and monochromatic synchrotron x-ray beam into a Si/polyimide/SiO₂ thin-film waveguide. The observed 20-fold flux increase agrees with theoretical predictions and was limited only by absorption of the 1 Å x rays in the waveguide structure.

©1993 The American Physical Society

URL: http://link.aps.org/abstract/PRL/v71/p537
DOI: 10.1103/PhysRevLett.71.537
PACS: 61.10.-i, 07.85.+n, 41.50.+h

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References

1. D. Marcuse, Theory of Dielectric Optical Waveguides (Academic, New York, 1974).
2. P. K. Tien and R. Ulrich, J. Opt. Soc. Am. 60, 1325 (1970) [ INSPEC].
3. R. E. De Wames and S. K. Sinha, Phys Rev. B 7, 917 (1973).
4. B. E. Warren, X-Ray Diffraction (Dover, New York, 1990).
5. E. Spiller and A. Segmüller, Appl. Phys. Lett. 24, 60 (1974) [CAS][ INSPEC].
6. Y. P. Feng and S. K. Sinha (to be published).
7. The PIQ series polyimide is a product of Hitachi Chemical Co., Ltd.
8. The magnitude of I^c_m depends on W and the bandwidth Gamma _m of the resonant coupling, and is maximized for W Gamma _m= 1.26 if the x rays are coherent across W.
9. The symmetric guide theory used in the paper does not predict the TE₄ mode as a guided one. The actual guide, however, has an asymmetric structure.
10. The electromagnetic theory overestimates the size of absorption dips by about a factor of 2. The observed dip size is partially accounted for by the coupled intensity into the guide.
11. This is due to a peculiar property of the RBC. Since resonant coupling only occurs when k_z= k₀ sin theta _in+- Gamma _m, with theta _in being very small, the acceptance range for energy Delta E / E at a fixed theta _in is much greater than the angular acceptance range Delta theta _in at a fixed energy.
12. Y. P. Feng, H. W. Deckman, and S. K. Sinha (to be published).
13. J. Wang, M. J. Bedzyk and M. Caffrey, Science 258, 775 (1992) [CAS][ INSPEC].

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