Abstract

The sensitivity of the reflectance vs angle of incidence method for measuring the optical constants n and k has been investigated using computer methods. Reflectance values for the perpendicular and parallel components R_s and R_p, and their average R_a, corresponding to unpolarized radiation, were computed. With these values, isoreflectance curves were plotted in the n–k plane using a computer–plotter combination. The angles of intersection of these isoreflectance curves provide a measure of the sensitivity of the method and are a function of n and k. For a given n and k, the sensitivity of the method is greatest using R_p and least using R_s Error studies showing the effects of nonparallelism and polarization of the incident radiation and error in reflectance measurement were made for R_p and R_a, but not for R_s because the lack of sensitivity of the method for this component renders it practically useless. The effect of errors was simulated by altering the computed reflectance values by a given amount and plotting the corresponding isoreflectance curves. It was found that the method is least sensitive to errors when using R_p. A scheme for plotting isoreflectance curves using a computer–plotter combination is given as well as an alternative scheme for digital computation of n and k without recourse to isoreflectance curves.

© 1965 Optical Society of America

Thickness of absorbing films necessary to measure their optical constants using the reflectance-vs-angle-of-incidence method

W. R. Hunter and G. Hass
J. Opt. Soc. Am. 64(4) 429-433 (1974)

Digital Evaluation of the Complex Index of Refraction from Reflectance Data*

D. W. Juenker
J. Opt. Soc. Am. 55(3) 295-299 (1965)

On the Cause of Errors in Reflectance vs Angle of Incidence Measurements and the Design of Reflectometers to Eliminate the Errors

W. R. Hunter
Appl. Opt. 6(12) 2140-2150 (1967)

Method of Using the Reflectance Ratios of Different Angles of Incidence for the Determination of Optical Constants

G. R. Field and E. Murphy
Appl. Opt. 10(6) 1402-1405 (1971)

Optical Constants of Metals in the Extreme Ultraviolet. I. A Modified Critical-Angle Technique for Measuring the Index of Refraction of Metals in the Extreme Ultraviolet*

W. R. Hunter
J. Opt. Soc. Am. 54(1) 15-19 (1964)