Non-axial-scanning multifocal confocal microscopy with multiplexed volume holographic gratings.

Confocal imaging techniques offer an optical sectioning capability to acquire three-dimensional information from various volumetric samples by discriminating the desired in-focus signals from the out-of-focus background. However, confocal, in general, requires a point-by-point scan in both the lateral and axial directions to reconstruct three-dimensional images. In addition, axial scanning in confocal is slower than scanning in lateral directions. In this Letter, a non-axial-scanning multifocal confocal microscope incorporating multiplexed holographic gratings in illumination and dual detection for depth discrimination is presented. Further, we demonstrate the ability of the proposed confocal microscopy to image ex vivo tissue structures simultaneously at different focal depths without mechanical or electro-optic axial scanning.