Extension of s2ISM to coherent image formation modalities

Determine whether modifying the forward model of Super-resolution Sectioning Image Scanning Microscopy (s2ISM) to accommodate coherent image formation (i.e., detection based on coherent optical processes rather than incoherent fluorescence) preserves the same benefits demonstrated for incoherent ISM, including enhanced lateral resolution and optical sectioning. Specifically, assess whether a coherent forward-model formulation of s2ISM yields comparable improvements, or whether alternative interferometric detection is required to achieve similar performance.

Background

The paper introduces Super-resolution Sectioning Image Scanning Microscopy (s2ISM), a reconstruction algorithm for laser scanning microscopes equipped with detector arrays that achieves super-resolution, improved optical sectioning, and high signal-to-noise ratio from single-plane acquisitions. The method is formulated for incoherent imaging modalities (e.g., fluorescence), leveraging the detector-plane fingerprint and a Poisson likelihood to disentangle in-focus and out-of-focus contributions.

In the Discussion, the authors consider extending s2ISM to coherent variants of image scanning microscopy. They note one approach would be to modify the forward model to reflect coherent image formation physics. However, they explicitly state uncertainty over whether such a coherent adaptation would confer the same benefits observed for incoherent cases. They also suggest an alternative strategy using interferometric detection, where intensities are replaced by fields, but do not resolve whether the benefits are equivalent.