Open AccessModel-based optimization of near-field binary-pixelated beam shapers
Author(s) -
C. Dorrer,
J. Hassett
Publication year - 2017
Publication title -
applied optics
Language(s) - English
Resource type - Journals
ISSN - 0003-6935
DOI - 10.1364/ao.56.000806
Subject(s) - pixel , optics , dither , halftone , transmission (telecommunications) , computer science , noise (video) , filter (signal processing) , algorithm , physics , artificial intelligence , computer vision , noise shaping , image (mathematics) , telecommunications
The optimization of components that rely on spatially dithered distributions of transparent or opaque pixels and an imaging system with far-field filtering for transmission control is demonstrated. The binary-pixel distribution can be iteratively optimized to lower an error function that takes into account the design transmission and the characteristics of the required far-field filter. Simulations using a design transmission chosen in the context of high-energy lasers show that the beam-fluence modulation at an image plane can be reduced by a factor of 2, leading to performance similar to using a non-optimized spatial-dithering algorithm with pixels of size reduced by a factor of 2 without the additional fabrication complexity or cost. The optimization process preserves the pixel distribution statistical properties. Analysis shows that the optimized pixel distribution starting from a high-noise distribution defined by a random-draw algorithm should be more resilient to fabrication errors than the optimized pixel distributions starting from a low-noise, error-diffusion algorithm, while leading to similar beam-shaping performance. This is confirmed by experimental results obtained with various pixel distributions and induced fabrication errors.