Multifocal confocal microscopy using a volume holographic lenslet array illuminator

Multifocal illumination can improve image acquisition time compared to single point scanning in confocal microscopy. However, due to an increase in the system complexity, obtaining uniform multifocal illumination throughout the field of view with conventional methods is challenging. Here, we propose a volume holographic lenslet array illuminator (VHLAI) for multifocal confocal microscopy. To obtain uniform array illumination, a super Gaussian (SG) beam has been incorporated through VHLAI with an efficiency of 43%, and implemented in a confocal microscope. The design method for a photo-polymer based volume holographic beam shaper is presented and its advantages are thoroughly addressed. The proposed system can significantly improve image acquisition time without sacrificing the quality of the image. The performance of the proposed multifocal confocal microscopy was compared with wide-field images and also evaluated by measuring optically sectioned microscopic images of fluorescence beads, florescence pollen grains, and biological samples. The proposed multifocal confocal system generates images faster without any changes in scanning devices. The present method may find important applications in high-speed multifocal microscopy platforms.