Simple structured illumination microscope setup with high acquisition speed by using a spatial light modulator

TL;DR

This paper presents a simple, high-speed structured illumination fluorescence microscope using a spatial light modulator and passive components, achieving near-diffraction-limited resolution at high frame rates.

Contribution

It introduces a straightforward setup with passive polarization and filtering components for rapid, high-contrast structured illumination microscopy.

Findings

Achieved lateral resolution of 114.2 nm

Operates at 7.6 frames per second

Uses passive components for high contrast

Abstract

We describe a two-beam interference structured illumination fluorescence microscope. The novelty of the presented system lies in its simplicity. A programmable electro-optical spatial light modulator in an intermediate image plane enables precise and rapid control of the excitation pattern in the specimen. The contrast of the projected light pattern is strongly influenced by the polarization state of the light entering the high NA objective. To achieve high contrast, we use a segmented polarizer. Furthermore, a mask with six holes blocks unwanted components in the spatial frequency spectrum of the illumination grating. Both these passive components serve their purpose in a simpler and almost as efficient way as active components. We demonstrate a lateral resolution of 114.2 +- 9.5 nm at a frame rate of 7.6 fps per reconstructed 2D slice.