Investigation of the extended focusing capability of the spherical aberration to enlarge the field of view in light-sheet fluorescence microscopy

Abstract

In light-sheet fluorescence microscopy (LSFM), using Gaussian beams for light-sheet generation results in a trade-off between the thickness and the field of view (FOV). Here we present a theoretical analysis of using spherical aberration to enlarge the FOV while keeping the light-sheet thickness small. Such spherical aberration can arise when focusing beams through an interface between materials of mismatched refractive indices. The depth-of-focus extension of the Gaussian beam is achieved when using air objectives to focus light into the samples dipped in the immersion medium with a higher refractive index. By scanning this elongated beam, a thin light sheet with a wide FOV can be used for LSFM imaging. Meanwhile, the accompanied sidelobes with the spherical aberrated light sheet, which are mainly distributed in the rear part of the light sheet, are also discussed. Simulation results show that an extended FOV of 64.4 µ m is possible for an objective lens of N A = 0.3 , which is about 5 times that of the unaberrated case. For such an extended FOV, a comparatively thin thickness of 1.38 µ m as well as the first sidelobe about 11.1% of the peak intensity in the center are also demonstrated.

Axially overlapped multi-focus light sheet with enlarged field of view

“…For example, the mSPIM [27] or SiMView [4] applied the dual-objective excitation configuration to double the FoV with similar axial resolution. Successive focus can be generated by axial scanning with tunable acoustic gradient-index (TAG) [28,29] lens, electrically tunable lens (ETL) [30,31], spatial light modulator (SLM) [32,33], multiconfiguration [34] and remote focusing optics [35,36]. Synchronization with a rolling shutter further increases the axial resolution [35].…”