Experimental validation of 20nm sensitivity of Singular Beam Microscopy

Quickly developing nanotechnology drives the industrial need for fast but sensitive nano-scale feature detection and evaluation. In this work we bypass the diffraction limit for achieving nanoscale sensitivity by introducing optical singularities into the illuminating beam for a modified laser scanning microscopic architecture. A good correspondence was obtained between laboratory experiments and corresponding simulations that indicated a theoretical potential of 1nm sensitivity under a practical signal to noise ratio of 30dB. For analysis of the experimental and simulation results, two simple but effective algorithms were developed. A significant improvement of signal to noise ratio in the optical system with coherent light illumination can be achieved by utilization a highly redundant data collected during experiments. Our experimental results validate achievable sensitivity down to 20nm. The unique combination of nano-scale sensitivity together with implementation simplicity and on-line, real-time analysis capability make Singular Beam Microscopy a valuable industrial analytic method.