Volumetric measurements in HiLo Microscopy based on adaptive lenses

HiLo microscopy uses a combination of images recorded with wide-field and speckled illumination to compute optically sectioned images. The achievable axial resolution is comparable to laser scanning confocal microscopy, but without the need for lateral scanning. Axial scanning is performed by mechanically moving the front-lens. In this contribution, we introduce a HiLo microscope where axial scanning is performed without mechanical motion. Instead, an electrically tunable lens is used in the illumination-path which enables three-dimensional image acquisition potentially much faster than the mechanical pendant. The performance of the microscope, like resolution and imaging rates, is characterized and the limitations are discussed. The measurement rate of the setup is primarily limited by the framerate of the camera. Hence, the use of an adaptive lens and a fast illumination switch (between uniform and structured illumination) enables to record a full-frame 3D image faster than a typical confocal microscope. First measurements of Zebrafish embryos proof the potential of our approach.