Accurate submicron edge detection using the phase change of a nano-scale shifting laser spot

Superresolution in phase image of π-phase step on plasmonic metasurface using differential heterodyne microscope

“…The nonlinear nature of the phase imaging leads to nonlinear distortions in the spatial spectrum of the final image, and therefore, in general, it is impossible to draw unambiguous conclusions about the steepness of the studied phase step based on the width of the phase response. Therefore, it is essential in this case that the concepts of resolution/superresolution are understood in terms of the accuracy of edge detection, 20 , 24 , 29 which is determined by the width of the phase response.…”

“…An important advantage of our method, as opposed to other techniques, 15 , 20 , 44 is that the superresolution effect is directly observable without additional processing of the phase response. We demonstrated that a metasurface can be used as a phase object for edge detection with superresolution.…”

“…In our work, we use the term “superresolution” in the sense of single-source resolution and it is devoted to a narrower specific aspect of superresolution, namely the problem of determining the position of the edge of a microobject 18 – 20 Tychinski was the first to notice the possibility of achieving superresolution in images of phase microobjects using optical interference microscopy 21 , 22 . This problem was investigated in detail by Totzek and Krumbugel, 23 where the presence of superresolution in phase images when detecting the edge of strip objects having a phase difference close to π using a microwave interferometer was confirmed and it was also noted that the nonlinearity of the phase image formation process plays an important role.…”