Image scanning microscopy using radially polarized beam with polarization conversion

• Published in: Optics communications 2024-10, Vol.569, p.130819, Article 130819
• Main Authors: Yuan, Xiaojin, Li, Haoqin, Chen, Rui
• Format: Article
• Language: English
• Subjects: Image scanning microscopy; Pixel reassignment; Polarization conversion; Radially polarized beam
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2024.130819

Image scanning microscopy (ISM), which combines the confocal scanning microscopy (CSM) with fast wide-field CCD detection, has been demonstrated in the fluorescent imaging, achieving both high resolution and signal to noise ratio (SNR). In this paper, we introduce radially polarized beam to ISM for non-fluorescent imaging. Radially polarized beam is applied to obtain a sharper illumination point spread function (PSF), along with a polarization converter to enhance detection PSF. It is found that the lateral resolution of ISM using radially polarized beam with polarization conversion (RPC-ISM) is improved to 0.28λ by a factor of 20%, as compared to traditional CSM. Further, images of complex object structures are simulated based on the complete model of scanning microscopy. Simulation results indicate an enhanced transverse resolution in RPC-ISM, compared with conventional ISM using circularly polarized beam. This technique can be used for label-free imaging such as semiconductor inspection, nano-lithography and so on. •A complete numerical model of image scanning microscopy (ISM) is proposed.•Radially polarized illumination with polarization conversion is utilized to improve the imaging capability.•Proposed model enables to analyze the imaging capability of ISM before experiment.