Abstract
The possibility of modulating a light beam by reflecting it from the surface of a crystal whose surface dielectric constant is modulated by an electric field is investigated theoretically. Since the dielectric constant may depend on distance in from the surface of the crystal it was necessary to develop a computer program which calculates the reflectivity of a medium with a non-uniform dielectric constant. To get an idea of the effect of spatial variations in the dielectric constant, the program is first used to calculate the reflectivity of media with simple ramps in their dielectric constant. The results show that a dielectric constant whose ramp extends at least one-third of a wavelength of light into the medium looks homogeneous to the light.
To estimate the effectivensss of a reflection modulator, the surface dielectric constant of CdS near a band edge is simulated both with and without a perturbing electric field and the reflectivity program is used to compute both the perturbed and unperturbed reflectivity. The best results, for a field of 106 volt/cm, are that a contrast ratio (ratio of reflectivities) of 17 can be obtained at an efficiency (largest reflectivity) of 1.7 percent.
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References
B. O. Seraphin, Semiconductors and Semi-Metals (R. K. Willardson and A. C. Beer, Eds., Academic Press, New York, 1969), Vol 4.
The effect of modulating with an electric field near the Brewster angle has been investigated by Fischer and Seraphin (Solid State Comm. 5, 973(1967) in the approximation o f a homogeneous crystal dielectric constant
D. E. Aspnes and A. From, Solid State Comm. 7, 155(1969).
M. Born and E. Wolf, Principles of Optics (Pergamon Press, London, 1970) Chapter 1.
E. A. Coddington and N. Levinson, Theory of Ordinary Differential Equations (McGraw-Hill Book Company, Inc., 1955), Chapter 1.
R. J. Elliott, Polarons and Excitons (C. G. Kuper and G. D. Whitfield, Eds., Oliver and Boyd, Ltd., London, 1963), p. 269.
M. F. Degan and M. D. Glinchuk, Soviet Physics — Solid State 5, 2377(1964).
The various parameters required in Eqs. (2) and (3) to specify the bulk dielectric constant may be obtained from D. G. Thomas and J. J. Hopfield, Phys. Rev. 116, 573(1959).
W. A. Albers, Jr., Phys. Rev. Letters 23, 410(1969).
J. G. Gay and L. T. Klauder, Jr., Phys. Rev. 172, 811(1968).
D. F. Blossey, Ph.D. Thesis, University of Illinois (1969).
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© 1971 Plenum Press, New York
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Klauder, L.T., Gay, J.G. (1971). Light Modulation by Reflection. In: Albers, W.A. (eds) The Physics of Opto-Electronic Materials. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-1947-4_5
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DOI: https://doi.org/10.1007/978-1-4684-1947-4_5
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4684-1949-8
Online ISBN: 978-1-4684-1947-4
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