A5059873330- Advanced Fluorescence Microscopy Techniques
- Optical Coherence Tomography Applications
- Digital Holography and Microscopy
- Electrowetting and Microfluidic Technologies
- Optical measurement and interference techniques
- Advanced optical system design
- Structural Health Monitoring Techniques
- Adaptive optics and wavefront sensing
- Image Processing Techniques and Applications
- High-pressure geophysics and materials
- Advanced Fiber Optic Sensors
- Optical Coatings and Gratings
- Advanced Optical Imaging Technologies
- Advanced Measurement and Detection Methods
- Laser-Plasma Interactions and Diagnostics
- Advanced Numerical Analysis Techniques
- Geotechnical and Geomechanical Engineering
- Electron and X-Ray Spectroscopy Techniques
- Advancements in Photolithography Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Near-Field Optical Microscopy
- Sensor Technology and Measurement Systems
- Laser-induced spectroscopy and plasma
- Structural Analysis of Composite Materials
- Rock Mechanics and Modeling
Technische Universität Dresden
2015-2024
Technical University of Darmstadt
2014
Electrically tunable lenses exhibit strong potential for fast motion-free axial scanning in a variety of microscopes. However, they also lead to degradation the achievable resolution because aberrations and misalignment between illumination detection optics that are induced by scan itself. Additionally, typically nonlinear relation actuation voltage displacement leads over- or under-sampled frame acquisition most microscopic techniques their static depth-of-field. To overcome these...
Abstract Diffraction-limited deep focusing into biological tissue is challenging due to aberrations that lead a broadening of the focal spot. The diffraction limit can be restored by employing aberration correction for example with deformable mirror. However, this results in bulky setup required beam folding. We propose bi-actuator adaptive lens simultaneously enables axial scanning and specimen-induced spherical compact setup. Using confocal microscope, we show diffraction-limited up 340 μm...
In this paper we present and verify the non-linear simulation of an aspherical adaptive lens based on a piezo-glass sandwich membrane with combined bending buckling actuation. To predict full piezoelectric behavior, measured charge coefficient, hysteresis creep effects piezo material inserted them into FEM model using virtual electric field. We further included discussed fabrication parameters -- glue layers thermal stress their variations. our simulations, fabricated set lenses different...
Due to their high stiffness-to-weight ratio, glass fiber-reinforced polymers are an attractive material for rotors, e.g., in the aerospace industry. A fundamental understanding of behavior requires non-contact, in-situ dynamic deformation measurements. The surface speeds and particularly translucence limit usability conventional optical measurement techniques. We demonstrate that laser Doppler distance sensor provides a powerful reliable tool monitoring radial expansion at fast rotating...
Deformable mirrors are the standard adaptive optical elements for aberration correction in confocal microscopy. Their usage leads to increased contrast and resolution. However, these improvements achieved at cost of bulky setups. Since spherical aberrations dominating microscopy, it is not required employ all degrees freedom commonly offered by deformable mirrors. In this contribution, we present an alternative approach microscopy based on a novel lens with two freedom. These lenses enable...
Tunable lenses are widely applied in imaging systems, as they provide inertia-free axial scanning. Their proper placement the system is critical to maximize tuning range and limit broadening of focal spot size. We introduce a purely analytic description optical systems employing tunable toolset find application-specific optimal trade-offs between these opposing goals. The proposed method selected configurations scanning derive expressions for their effective length On this basis, we...
We present a HiLo microscope with an electrically tunable lens for high-contrast three-dimensional image acquisition. microscopy combines wide field and speckled illumination images to create optically sectioned images. Additionally, the depth-of-field is not fixed, but can be adjusted between confocal-like axial resolution. incorporate in scanning, obtain data without need of moving neither sample nor objective. The used adaptive consists transparent polydimethylsiloxane (PDMS) membrane...
We present a fluid-membrane lens with two piezoelectric actuators that offer versatile, circular symmetric surface shaping. A wavefront-measurement-based control system ensures robustness against creeping and hysteresis effects of the actuators. apply adaptive to correct synthetic aberrations induced by deformable mirror. The results suggest is able spherical standard Zernike coefficients between 0 μm 1 μm, while operating at refractive powers up about 4m<sup>-1</sup>. in custom-built...
Adaptive lenses offer fast and flexible scans without mechanical movement. However, driving the lens to achieve desired behavior is challenging requires online monitoring. The demand for monitoring techniques can be high when with large tuning ranges or multiple degrees of freedom are employed. We analyze performance a partitioned aperture wavefront (PAW) as tool in situ in-process adaptive lenses. PAW has advantage enabling measurements input angles thus high-tuning-range just single beam...
The enhancement effect of a microstructured surface on laser absorption and characteristic <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi mathvariant="normal">K</a:mi><a:mi>α</a:mi></a:mrow></a:math> emission has been investigated by measuring K-shell from titanium (Ti) targets irradiated with high-intensity (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mo>∼</c:mo><c:msup><c:mn>10</c:mn><c:mn>20</c:mn></c:msup><c:mspace...
We report on the characterization of an image plate and its absolute calibration to electrons in low keV energy range (1-30 keV). In our case, Agfa MD4.0 without protection layer was used combination with a Fuji FLA7000 scanner. The data are compared other published consistent picture sensitivity plates is obtained, which suggests validity obtained up 100 keV.
We propose a HiLo microscope that employs adaptive lens based axial scanning for volumetric measurements. Its application fluorescence measurements of transgenic zebrafish is presented and lenses with tunable asphericity are introduced.
Microscopic techniques with high spatial and temporal resolution are required for in vivo studying biological cells tissues. Adaptive lenses exhibit strong potential fast motion-free axial scanning. However, they also lead to a degradation of the achievable because aberrations. This hurdle can be overcome by digital optical technologies. We present novel High-and-Low-frequency (HiLo) 3D-microscope using structured illumination an adaptive lens. Uniform is used obtain sectioning...
The high stiffness to weight ratio of glass fibre-reinforced polymers (GFRP) makes them an attractive material for rotors e.g. in the aerospace industry. We report on recent developments towards non-contact, in-situ deformation measurements with temporal resolution up 200 µs and micron measurement uncertainty. determine starting point damage evolution inside rotor through radial expansion measurements. This leads a better understanding dynamic behaviour regarding prediction initiation...
Adaptive lenses enable compact, fast and quasi-motionless scanning in optical microscopy [1]. One drawback, however, is that the elements of an imaging system are usually optimized for a certain design-focal-length adaptive lens. In particular, spherical aberrations negatively influence axial lateral resolution as well signal strength confocal microscope. We address this problem using novel fluid-membrane lens based on piezo-glass composite membrane, where ultrathin glass membrane sandwiched...
We use quantitative phase imaging based on partitioned-aperture wavefront sensing to monitor and control the behavior of novel adaptive lenses that enable simultaneous axial scanning aberration control.