Lissajous multi-modal endomicroscopy with optical coherence tomography and confocal fluorescence microscopy

Abstract

We present a multi-modal endomicroscopic system integrating confocal fluorescence microscopy (CFM) and op tical coherence tomography (OCT) into a compact, resonant fiber scanner. The probe employs an asymmetric double D-shaped fiber cantilever to achieve axis-dependent frequency separation, enabling Lissajous scanning. An analytical model was formulated to predict tip displacement by combining geometric amplification, quality factor enhancement, and frequency-dependent transfer functions. This model captured axis-specific dynamics and guided cantilever-holder optimization via simulation. The probe achieved lateral and axial resolutions of 2.19 & micro;m and 23.66 & micro;m in CFM mode, and 24.77 & micro;m and 6.98 & micro;m in OCT mode. Ex vivo fluorescein-stained porcine stomach imaging confirmed simultaneous acquisition of en-face fluorescence and depth-resolved OCT images. These results validate the system's ability to deliver complementary contrast and spatially correlated structural information in a compact platform. This multi-modal approach promises real-time surgical guidance and label-assisted diagnostics in clinical settings.