Fast structured illumination microscopy using rolling shutter cameras

Spatial light modulators (SLM) update in a synchronous manner, whereas the data readout process in fast structured illumination systems is usually done using a rolling shutter camera with asynchronous readout. In structured illumination microscopy (SIM), this leads to synchronization problems causing a speed limit for fast acquisition. In this paper we present a configuration to overcome this limit by exploiting the extremely fast SLM display and dividing it into several segments along the direction of the rolling shutter of the sCMOS camera and displaying multiple SLM frames per camera acquisition. The sCMOS runs in continuous rolling shutter mode and the SLM keeps the readout-line always inside a dark region presenting different SIM patterns before and after the readout/start-exposure line. Using this approach, we reached a raw frame rate of 714 frames per second (fps) resulting in a two-beam SIM acquisition rate of 79 fps with a region of interest (ROI) of 16.5 x 16.5 mu m(2).