Design and Function of a Structured Illumination System For Use In An AO Microscope

The design and function of a Strucutred Illumination system for use as part of an Adaptive Optics Structured Illumination Microscope (AOSIM) is presented. After successful implementation of AO in a standard widefield microscope, our lab wanted to apply the technology to a more advanced imaging modality that has a lot to gain from the AO system. SIM allows us to reconstruct an image with resolution beyond the Rayleigh limit of the optics, called a super-resolution image, by aliasing high spatial frequencies, outside the limit of the optics, to lower frequencies within the system pass band. The aliasing is accomplished by spatially modulating the illumination at a frequency near the cutoff frequency of the system. These aliased frequencies are superimposed on the lower spatial frequencies of the object in our image. Using multiple images and an inverse algorithm, we separate the aliased and normal frequencies, restore them to their original frequency positions, and recreate the original spectrum of the object. This allows us to recreate a super-resolution image of the object. We show that our SIM system creates images that are a higher resolution than a standard wide-field microscope