Tunable, Nonmechanical, Fractional Talbot Illuminators

Abstract

Inside an optical Fourier processor, we inserted a varifocal system to continuously magnify the frequency of a master grating. The proposed system does not involve any mechanical compensation for scaling the Fourier spectrum. As the magnification, M, varies, the Fourier spectrum remains at the same initial location. We identified a previously unknown quadratic phase factor for generating, in the fixed output plane, Talbot images of any fractional order. We applied this result to setting a structured illumination beam, which does not have occluding regions. This illuminating beam can be useful for Talbot interferometry.

Talbot-Lau devices: a reappraisal

“…Here, we concentrate our discussions on a Gaussian design of a system for tuning the magnification of the Fourier spectrum of a grating. For the sake of completeness, we include some previously results that are not well-known (Mishra et al, 2014;Lee et al, 2019;Gómez-Sarabia and Ojeda-Castañeda, 2020a;Gómez-Sarabia and Ojeda-Castañeda, 2020b;Song et al, 2020;Gómez-Sarabia and Ojeda-Castañeda, 2021;Gómez-Sarabia and Ojeda-Castañeda, 2023b).…”