Computational Modeling of SIM Imaging Using Grating-Based Illumination

The resolution limit imposed by diffraction in traditional widefield microscopy can be doubled with structured illumination microscopy (SIM), a potent super-resolution imaging technique. SIM is a vital tool in biological research, providing high-resolution, live-cell imaging using standard fluorescent labels to reveal fine subcellular structures and dynamic processes. The effect of crucial system parameters on the resolution of SIM-reconstructed images is examined, with a focus on diffraction grating configurations and their dynamic modulation techniques. Mixing of the illumination pattern's spatial frequency and orientation, often produced by diffraction gratings, allows researchers to produce high frequency fringe patterns that are appropriate for resolving sub-diffraction features.

Further, to obtain a final reconstructed image, the presentation highlights the tradeoffs between illumination wavelength, grating pitch, and resolution. The work focuses on the use of single versus dual gratings for pattern generation. Systems with single diffraction gratings are mechanically simple compared to dual gratings. In contrast, counter rotating dual grating systems enable more angular diversity in the illumination patterns, which results in better isotropic coverage of spatial frequencies and, ultimately, higher resolution. It has been demonstrated there is great value carefully adjusting parameters like grating grooves, illumination pattern frequency, phase shift accuracy, and filtering strength provides an easily accessible superresolution platform.

About the presenter
Avani Premprakash is a Ph.D. scholar working under the guidance of Sandeep Chakraborty, Ph.D., in the research group ‘ECO-BIONICS’, Department of Physics, School of Advanced Sciences, Vellore Institute of Technology (VIT), Tamil Nadu, India.

She received her bachelor’s degree in physics from Bishop Chulaparambil Memorial College, Mahatma Gandhi University in 2020 and master’s degree in applied physics with specialization in photonics from CMS College, India, in 2022. Her research interests include optical microscopy, medical imaging, super-resolution microscopy, deep tissue imaging, and AI & ML in biophotonics. Her current field is in super-resolution optical microscopy systems tailored for deep tissue imaging applications.