Fast-scanning two-photon fluorescence imaging based on a microelectromechanical systems (MEMS) two-dimensional scanning mirror

James H. Clark Center for Biomedical Engineering & Sciences, Stanford University, Stanford, California 94305, USA.
Optics Letters (Impact Factor: 3.29). 08/2006; 31(13):2018-20. DOI: 10.1364/OL.31.002018
Source: PubMed


Towards overcoming the size limitations of conventional two-photon fluorescence microscopy, we introduce two-photon imaging based on microelectromechanical systems (MEMS) scanners. Single crystalline silicon scanning mirrors that are 0.75 mm x 0.75 mm in size and driven in two dimensions by microfabricated vertical comb electrostatic actuators can provide optical deflection angles through a range of approximately16 degrees . Using such scanners we demonstrated two-photon microscopy and microendoscopy with fast-axis acquisition rates up to 3.52 kHz.

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    • "The recent advancement in miniaturized scanning mirrors based on microelectromechanical systems (MEMS) technology has enabled the feasibility of fabricating compact fiber-optic-based endomicroscopic probes [23] [24] [25] [26]. In our previous work, we have successfully built an all-optical MEMS-based PAM system using miniature components and achieved imaging of microvasculatures inside a canine bladder wall [27]. "
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    • "Despite their rather established place on the MEMS landscape, novel applications of micromirrors continue to emerge, thanks to the perpetual interest they attract from the industry and academy alike. Some of the most recent research fields actively making use of micromirrors in one form or another, include endoscopic medical imaging (optical coherence tomography [1], two-photon microscopy [2], etc), 3D optical tracking [3], and projection displays [4]. The dominant trend in scanning mirrors favored small (usually smaller than 1.5 mm), but very fast devices that enable high resolution and high refresh rate operation. "
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    • "The introduction of compound gradient refractive index (GRIN) lenses as focusing optics [44, 49, 50], double-clad photonic crystal fibers [51, 52] for superior detection efficiency and mechanical flexibility, and microelectromechanical systems (MEMS) scanning mirrors [52–54] has been among the most important technological advancements towards microendoscopy. The majority of micro-lenses used in nonlinear imaging, GRIN lenses, have a typical size of 0.2–1 mm in diameter, 1–10 cm in length, and a numerical aperture of less than 0.6. "
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