Sub-Diffraction-Limit Realization and Micro-displacement measurements via complex Gaussian-correlated beam

Abstract Overcoming the Rayleigh diffraction limit has been a longstanding focus in optical field. In this paper, a complex Gaussian-correlated beam was used as the illumination source, which renders the minimum resolution distance of four symmetrical pinholes at least 0.05 times the Rayleigh diffraction limit. In addition, the method was applied in displacement measurements, which can measure a displacement below the Rayleigh diffraction limit. The theoretical results show that the complex Gaussian-correlated beam has a great potential to realize sub-diffraction-limit and micro-displacement measurements.