Three-dimensional nanoscale optical vortex profilometry

摘要

Practical application of optical vortex in a method of three-dimensional profilometry with nanoscale resolution was considered. It was shown that phase analysis of coherent light beam carrying axial optical vortex allow to retrieve information about sample surface relief. High spatial resolution caused by vortex helical phase sensitivity to disturbances in wave front after reflection or spreading through studying sample, which can be optically transparent or have a reflecting surface. This method applicable for non-destructive testing of live cells and biological tissues in real-time regime with exceeding optical diffraction limit. Computer processing of vortex interferograms allow to achieve a vertical resolution down to 1,75 nm. Specially designed optical scheme reduces an environment influence, in particular, vibration, misalignment of test sample and its local anisotropy and provides the possibility of investigating surfaces of large linear dimensions. The prospective tasks of automated systems creation for monitoring of surface quality were proposed, in particular those that will could be developed with methods based on singular optics and phase singularities.