Seminarium Optyczne

Structured light with non-Gaussian intensity profiles and with spatially variant phase distributions is getting attention in many fields of optical science and technology. A special case of such beams is a vortex beam, which features a helical shaped wavefront and annular intensity distribution. An optical vortex is a singular phase structure having a point to which the equiphase lines converge (vortex point). They attract attention in modern optical metrology because they are stable structures having a characteristic point of zero intensity (at the vortex point) and can serve as precise position markers. On the other hand, they are well-defined points on the phase map and can be localized with arbitrary accuracy, at least in theory. In the talk, I will present the approaches that have been made to apply optical vortices in metrology. In particular, I will focus on the optical vortex scanning microscope. In this instrument, we propose to use the focused vortex beam to illuminate the sample. The investigated sample interacts with the illuminating beam that contains an area of low amplitude and fast-changing phase. That makes the beam sensitive to any phase or amplitude perturbations. I will present the results we obtained during our research on this instrument.