Confocal fluorescence microscope with dual-axis architecture and biaxial postobjective scanning

We present a novel confocal microscope that has dual-axis architecture and biaxial postobjective scanning for the collection fluorescence images from biological specimens This design uses two. low-numerical-aperture lenses to achieve high axial resolution and long working distance, and the scanning mirror located distal to the lenses rotates along the orthogonal axes to produce arc-surface images over a large field of view (FOV). With fiber optic coupling, this microscope can potentially be scaled down to millimeter dimensions via microelectromechanical systems (MEMS) technology. We demonstrate a benchtop prototype with a spatial resolution less than or equal to4.4 mum that collects fluorescence images with a high SNR and a good contrast ratio from specimens expressing GFR Furthermore, the scanning mechanism produces only small differences in aberrations over the image FOV. These results demonstrate proof of concept of the dualaxis confocal architecture for in vivo molecular and cellular imaging. (C) 2004 Society of Photo-Optical Instrumentation Engineers.