Spatial light modulators in fluorescence microscopy

Spatial light modulators (SLMs) are becoming increasingly important in optical microscopy. These reflective or transmissive devices, based on microdisplays using liquid crystal or micromirror array technology, are used to achieve a variety of useful effects and imaging modes. When placed in an image plane, SLMs can be used to create arbitrary, computer controlled masks. These masks can then be placed in the microscope's illumination pathway, detection pathway, or both. The result is a programmable array microscope (PAM): an optical sectioning microscope with improved speed, sensitivity, and flexibility compared to conventional confocal laser scanning microscopes (CLSMs). Another possibility is structured illumination microscopy (SIM), in which SLMs are used only for illumination. Both high speed optical sectioning and live cell, 3D superresolution can also be achieved via SIM. When placed in an aperture plane, SLMs can manipulate the reflected wavefront. This allows for applications such as adaptive optics.