title: Volumetric HiLo microscopy employing an electrically tunable lens.
abstract: Electrically tunable lenses exhibit strong potential for fast motion-free axial scanning in a variety of microscopes. However, they also lead to a degradation of the achievable resolution because of aberrations and misalignment between illumination and detection optics that are induced by the scan itself. Additionally, the typically nonlinear relation between actuation voltage and axial displacement leads to over- or under-sampled frame acquisition in most microscopic techniques because of their static depth-of-field. To overcome these limitations, we present an Adaptive-Lens-High-and-Low-frequency (AL-HiLo) microscope that enables volumetric measurements employing an electrically tunable lens. By using speckle-patterned illumination, we ensure stability against aberrations of the electrically tunable lens. Its depth-of-field can be adjusted a-posteriori and hence enables to create flexible scans, which compensates for irregular axial measurement positions. The adaptive HiLo microscope provides an axial scanning range of 1 mm with an axial resolution of about 4 μm and sub-micron lateral resolution over the full scanning range. Proof of concept measurements at home-built specimens as well as zebrafish embryos with reporter gene-driven fluorescence in the thyroid gland are shown.
authors.forename: Katrin
authors.initials: K
authors.lastname: Philipp
authors.forename: André
authors.initials: A
authors.lastname: Smolarski
authors.forename: Nektarios
authors.initials: N
authors.lastname: Koukourakis
authors.forename: Andreas
authors.initials: A
authors.lastname: Fischer
authors.forename: Moritz
authors.initials: M
authors.lastname: Stürmer
authors.forename: Ulrike
authors.initials: U
authors.lastname: Wallrabe
authors.forename: Jürgen W
authors.initials: JW
authors.lastname: Czarske
mesh_terms: D004560:Electricity; D004867:Equipment Design; D007908:Lens, Crystalline; D007909:Lenses; D008029:Lighting; D008853:Microscopy