Simulation and analysis of variable numerical aperture wide-field microscopy for telecentricity with constant resolution

Abstract

In this work, we propose simulation and analysis of a novel combination of a variable numerical aperture wide-field microscope objective with an Electrically Tunable Lens (ETL) for axial scanning with a telecentric image space. This work resolves the challenges of the conventional ETL based wide-field microscopic systems viz. variable magnification, field-of-view (FOV), an inconsistent lateral and axial resolution. The proposed combination performs the tuning of the object plane by changing ETL current and effectively modifies the object space numerical aperture using an aperture controller to provide a stationary telecentric image plane. Moreover, with the proposed combination, the lateral resolution of the system is preserved over an axial range of 7.586mm with a magnification error of 2.55 %. The proposed work witnesses the advantages of providing fast axial scanning, extended axial scanning range, autofocusing, invariant magnification, constant FOV, and constant resolution along with a compact optical setup.

Keywords: Autofocusing; Electrically Tunable Lens; Telecentricity; Variable numerical aperture microscope objective.