Finite-area centroid propagation in homogeneous media and range of validity of the Optical Ehrenfest's Theorem
✍ Scribed by Jorge Ares; Justo Arines; Salvador Bará
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 274 KB
- Volume
- 284
- Category
- Article
- ISSN
- 0030-4018
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✦ Synopsis
The estimation of unknown wavefronts using Hartmann-Shack and other wavefront sensing devices relies on the fact that the irradiance centroids in homogeneous media propagate along straight lines whose slopes are given by the irradiance-weighted spatial average of the local wavefront slopes, a result which is a particular case of the Optical Ehrenfest's Theorem. The strict analytic validity of this theorem, however, heavily depends on the use of an infinitely extended integration region to compute the irradiance centroid. In this paper we describe the equation governing the centroid propagation in homogeneous media when it is computed within a finite region of the detection plane and determine the minimum size of this region sufficient to ensure an approximate fulfillment of the Optical Ehrenfest's Theorem.