Point Spread Function Measurement and Analysis of Three Dimensional Optical Imaging System

摘要

Optical coherence tomography (OCT) and confocal scanning microscopes can perform three dimensional (3D) opticalimaging of target objects. They are widely used in many fields because of their non-contact measurement, real-time fastimaging and high resolution. This paper is dedicated to evaluating the resolution of 3D optical imaging systems, enablingthird-party metrology assessment, assuring periodic quality, and comparing different systems. An improved standard testmethod based on the system 3D point spread function (PSF) is proposed in this paper. The standard diameter microsphereswere embedded in the robust PSF phantoms as scattering particles. An OCT and a confocal scanning microscope wereused to acquire the 3D PSF images. Different from previous studies, this paper proposes a new preparation process for PSFphantoms. In addition, new mathematical model was built based on statistical methods to analyze the PSF that includeshundreds of scattered data. Combining the imaging principles of OCT and confocal microscopy, the imaging resolution ofthe two optical systems was compared. Finally, a stability experiment was performed to further verify the feasibility ofusing the PSF to evaluate the resolution performance of the imaging system. The results showed that the resolution basedon PSF analysis is in good agreement with the theoretically calculated value, and this method can be used to reliablyevaluate the resolution of 3D optical imaging system in the future.