100k-frame-rate high-speed imaging by interferometric FRAME using galvanometer scanner

We present an interferometric FRAME system operating at ~100,000 frames per second (fps), employing an electrically modulated diode laser and a resonant galvanometer scanner within an off-axis Michelson interferometer. The laser allows flexible adjustment of the frame rate in high-speed imaging, while the galvanometer scanner improves mirror rotation speed compared to the stepping motor-based systems used in our previous study. Synchronization of the scanner, pulse injection, and camera exposure by a self-made electronic circuit enables capture of the time series of a rotating optical chopper at 95 kfps (i.e. nearly 100 kfps). Spatial resolution tests using a USAF target yields 44 μm with an NA=0.16 optical system. Further improvement is possible by optimizing the interference fringes (i.e., frequency spacing in Fourier domain). This compact, cost-efficient system enables high-speed imaging from the microsecond scale using a general-purpose camera. Specifically, utilizing FRAME’s wide-field imaging capability allows extension to high-speed microscopy through integration of our system into microscopes.