A High-Speed Confocal Laser Endomicroscope Using an Electrothermal Mems Mirror Actuated in Linear-Near Resonant Raster Scan

Confocal laser endomicroscopy has profound impact in precision medicine, but is still facing challenges of ensuring high-speed in vivo imaging and guaranteeing safety. Electrothermal micromirrors typically have large linear angular scan range at low actuation voltage, allowing the safe laser scanning imaging. This paper reports a confocal endomicroscope using a two-axis electrothermal MEMS mirror actuated in near resonance to achieve a stable high-speed imaging. Fluorescent beads and micromachined patterns are used to test the probe performances. Experiments show that the lateral resolution is 4.15 μm and the field of view is about 300×800 μm
²
. The imaging speed can be set from 1 fps to 20 fps with different pixel resolutions. In a linear-near resonant mode, the imaging frame rate of the probe is 20 times faster than that of a linear-linear mode at the same pixel numbers.