Improving resolution by the higher-order microscope imaging system with thermal light

Abstract

The resolution properties of the higher-order ghost imaging with thermal light source are investigated. In a multi-arm microscope imaging scheme with thermal light, we compare the resolution of the images obtained by the higher-order correlation with that by the lower-order correlation, and show that the resolution of the images can be enhanced with an increasing number of the reference arms. The effects from the aperture of the reference lens are also discussed. In recent years, ghost imaging, ghost interference, and subwavelength interference have been investigated extensively both in quantum field and classical field. The first coincidence imaging experiment was performed based on entangled photon pairs generated by spontaneous parametric down-conversion (SPDC)[1]. While Bennink et al. provided an experimental demonstration of ghost imaging by using a classical source[2]. Compared with entangled source, the visibility of the second-order correlated imaging with thermal source is quite low, which could become the obstacle for the applications of the imaging technique. To enhance the visibility, some efforts turned to higher-order ghost imaging[3-7]. As pointed in Refs. [4, 5], the higher-order intensity correlation could improve the visibility and the resolution of the interference pattern in a double-slit interference scheme when compared with the lower-order intensity correlation. However, their work focused on the higher-order ghost interference and diffraction, the resolution of the higher-order ghost imaging was not mentioned. In this Letter, we discuss the higher-order microscope imaging with thermal source. Based on the analytical results and the numerical simulations, we show that the resolution of the images can be enhanced with an increase of the reference arms in a multi-arm microscope imaging system.