Abstract
Experimental results of thermal emittance from lamellar gratings in intrinsic silicon are presented along with a theoretical discussion. For azimuthal angular directions in shallow gratings, enhanced thermal emission plateaus and maxima are observed. In the case of p-polarized emission in the Φ = 90° azimuth (parallel to the grating vector), the plateau arises when two diffractive orders can be supported; it lies between the Rayleigh polar angles corresponding to the forbidden zone. The experimentally observed angular dependence of the s-polarized emission for the Φ = 90° azimuth has been compared with a coupled-wave calculation, and a respectable agreement has been obtained. For the experimentally observed s-polarized emission in the Φ = 0° azimuth (perpendicular to the grating vector), there is an onset of enhanced emission at the polar angles that follows a simple empirical relation unrelated to any known diffraction law. By contrast, the p-polarized emission in the Φ = 0° azimuth shows relatively little structure. These data illustrate the value of thermal emission for surveying multivariate absorption processes involving microstructures.
© 1993 Optical Society of America
Full Article | PDF ArticleMore Like This
T. K. Wang and Jay N. Zemel
Appl. Opt. 31(6) 732-736 (1992)
Frederick C. Evering
Appl. Opt. 5(8) 1313-1317 (1966)
Eugene K. Popov, Lyuben B. Mashev, and Erwin G. Loewen
Appl. Opt. 28(5) 970-975 (1989)