Prof. Alexander Heisterkamp Profile

Prof. Alexander Heisterkamp

Researcher/Head of Biophotonics Group at Leibniz Univ Hannover

SPIE Involvement:

Conference Program Committee | Author | Editor

Publications (75)

Proceedings Article | 20 June 2024 Poster + Paper

Development of a linear optical coherence tomography low-cost system for ophthalmic applications

Niklas Bauer, Damian Mendroch, David Harings, Jan Matrisch, Uwe Oberheide, Alexander Heisterkamp

Proceedings Volume 13006, 130061B (2024) https://doi.org/10.1117/12.3016988

KEYWORDS: Optical coherence tomography, Imaging systems

Read Abstract +

Proceedings Article | 20 June 2024 Poster + Paper

Deconvolution-based image enhancement for optical coherence tomography

Damian Mendroch, Niklas Bauer, David Harings, Alexander Heisterkamp

Proceedings Volume 13006, 130061A (2024) https://doi.org/10.1117/12.3016987

KEYWORDS: Optical coherence tomography, Deconvolution, Convolution, Image processing, Image enhancement, Image deconvolution, Signal processing, Image denoising

Read Abstract +

Proceedings Article | 20 June 2024 Presentation

Characterisation and differentiation of oral bacteria using ATR-FTIR spectroscopy

Katharina Frings, Nils Heine, Nicolas Debener, Thomas Scheper, Janina Bahnemann, Katharina Nikutta, Maria Leilani Torres-Mapa, Alexander Heisterkamp

Proceedings Volume PC13006, PC1300604 (2024) https://doi.org/10.1117/12.3021519

Read Abstract +

Proceedings Article | 20 June 2024 Presentation

Biocompatible hydrogel-based plasmonic sensor for glucose sensing

Ammar Ahmed, Thore Amend, Christina Wenck, Mitsuhiro Terakawa, Maria Leilani Torres-Mapa, Alexander Heisterkamp

Proceedings Volume PC13008, PC1300803 (2024) https://doi.org/10.1117/12.3017510

Read Abstract +

Proceedings Article | 20 June 2024 Presentation

Light delivery using a tapered optical fiber for optogenetic stimulation in mouse auditory midbrain

Meike Rogalla, Michael Tomanek, Gunnar Quass, Sabri Deniz Ünlü, Alexander Heisterkamp, Maria Torres-Mapa

Proceedings Volume PC13007, PC1300701 (2024) https://doi.org/10.1117/12.3022082

KEYWORDS: Optogenetics, Tapered optical fibers, Optical switching, Optical fibers, Resolution enhancement technologies, Neurons, Nervous system, Auditory cortex

Read Abstract +

Proceedings Article | 19 June 2024 Presentation

Comparative studies on UVA and femtosecond corneal crosslinking characterized using Brillouin microscopy

Christian Alejandro Iriarte Valdez, Johannes Wenzel, Maria Leilani Torres-Mapa, Alexander Heisterkamp, Oliver Stachs, Colette Leyh, Emilie Baron, Alexandra Claus

Proceedings Volume PC13010, PC1301003 (2024) https://doi.org/10.1117/12.3016711

KEYWORDS: Femtosecond phenomena, Cornea, Microscopy, Collagen, 3D acquisition, Viscoelasticity, Transparency, Laser irradiation, Diseases and disorders

Read Abstract +

Proceedings Article | 17 March 2023 Presentation

Spatiotemporal optogenetic control of cardiomyocyte excitability using a microLED array

Sebastian Junge, Masa Al Masri, Ricci Signorini, Monika Szepes, Jan Guelink, Heiko Brüning, Ina Gruh, Maria Leilani Torres-Mapa, Alexander Heisterkamp

Proceedings Volume PC12366, PC1236606 (2023) https://doi.org/10.1117/12.2662749

KEYWORDS: Optogenetics, Tissue optics, Calcium, Tissues, Stem cells, Spatial light modulators, Modulation, Mirrors, Luminescence, Light sources

Read Abstract +

Proceedings Article | 6 March 2023 Presentation

Correlative imaging and quantification of the tumor microenvironment of triple-negative-breast-cancer using lightsheet microscopy, scanning laser optical tomography, and TPEF

H. Kamin, L. Nolte, J. Maurer, E. Stickeler, D. Heinemann, A. Heisterkamp, S. Johannsmeier, T. Ripken

Proceedings Volume PC12371, PC1237104 (2023) https://doi.org/10.1117/12.2648373

KEYWORDS: Microscopy, Tumors, Optical tomography, Laser optics, Optical microscopy, Luminescence, Breast cancer, 3D image processing, Tumor growth modeling, Statistical modeling

Read Abstract +

Proceedings Article | 1 April 2022 Presentation

Laser direct writing of functional microstructures in transparent soft materials using femtosecond laser

Mitsuhiro Terakawa, Shuichiro Hayashi, Fumiya Morosawa, Hirofumi Tomikawa, Yo Nagano, Manan Machida, Hiroaki Onoe, Alexander Heisterkamp

Proceedings Volume PC11989, PC1198903 (2022) https://doi.org/10.1117/12.2607530

KEYWORDS: Femtosecond phenomena, Biomedical optics, Metals, Graphene, Crystals, Carbon, Piezoresistive sensors, Nanofibers, Laser crystals, Gold

Read Abstract +

Proceedings Article | 9 December 2021 Paper

OCT wavenumber calibration with simple reference arm modification

Miroslav Zabic, Simon Hansert, Sonja Johannsmeier, Dag Heinemann, Alexander Heisterkamp, Tammo Ripken

Proceedings Volume 11924, 119241L (2021) https://doi.org/10.1117/12.2616143

KEYWORDS: Calibration, Optical coherence tomography, Glasses, Reflection, Mirrors, Signal processing, Fourier transforms, Infrared detectors, Imaging systems, Free space optics

Read Abstract +

Proceedings Article | 3 December 2021 Paper

Holographic optogenetic stimulation with calcium imaging to probe and visualize cardiac activity

Sebastian Junge, Felix Schmieder, Phillip Sasse, Jürgen Czarske, Maria Leilani Torres-Mapa, Alexander Heisterkamp

Proceedings Volume 11921, 119210G (2021) https://doi.org/10.1117/12.2615634

KEYWORDS: Calcium, Optogenetics, Luminescence, Visualization, Holography, Spatial light modulators, Photostimulation, Tissue optics, Imaging systems, Error analysis

Read Abstract +

Proceedings Article | 5 March 2021 Presentation + Paper

Charged fluorophores-assisted fabrication of metallic structures inside hydrogel by multi-photon photoreduction

Manan Machida, Weilu Shen, Hiroaki Onoe, Alexander Heisterkamp, Eric Mazur, Mitsuhiro Terakawa

Proceedings Volume 11676, 116760R (2021) https://doi.org/10.1117/12.2578247

KEYWORDS: Ions, Metals, Gold, Molecules, Absorbance, Oxidation, Microfabrication, Biomedical optics

Read Abstract +

Proceedings Article | 1 April 2020 Presentation

Holographic optogenetic stimulation with calcium imaging as an all-optical tool for cardiac electrophysiological studies (Conference Presentation)

Sebastian Junge, Felix Schmieder, Philipp Sasse, Jürgen Czarske, Maria Leilani Torres-Mapa, Alexander Heisterkamp

Proceedings Volume 11359, 1135917 (2020) https://doi.org/10.1117/12.2554011

KEYWORDS: Optogenetics, Action potentials, Holography, Calcium, Electrophysiology, Visualization, Atrial fibrillation, Heart, Mouse models, Tissue optics

Read Abstract +

On cellular or tissue level, electrophysiology studies during light stimulation with shaped light can potentially enable the design of effective stimulation strategies towards future cardiac therapies. In this work, we explore the use of optogenetics in probing the electrophysiology of a functional cardiac syncytium. A holographic technique with the use of a spatial light modulator allows beam shaping and precise spatiotemporal control of the origin of action potential in a cardiac-like cell line monolayer. Depolarization was performed by using a blue laser (488 nm) incident to a reflective ferroelectric liquid crystal on silicon spatial light modulator (FLCOS-SLM) which generates multiple foci on to cardiomyocyte-like cells (HL1 line) expressing the light-gated protein Channelrhodopsin-2 (ChR2). The calcium-sensitive fluorophore Cal-630 was used to visualize the cellular electrical activity and thus can be combined with ChR2 as an all-optical method to stimulate and visualize electrophysiology of cardiac-like cells in a non-contact manner. We generated single or multiple foci each with spot size of ~5 µm for optogenetic stimulation. The probability of triggering an action potential, which we refer to as excitation probability, is highly dependent on the laser intensity. The threshold intensity for a single beamlet, where approximately 50% of the laser pulses successfully trigger an action potential, is ~4 µW/μm² (n=5 regions, 5 cells analyzed per region, performed in triplicates) at frequency of 1 Hz and pulse duration of 10 ms. We also demonstrate spatial summation of membrane potential in HL1-ChR2. Generated multiple foci can render the excited cells as individual inputs to elicit action potential in a syncytium. We demonstrate the dependence of the excitation probability on the foci gap distance. Two foci, each with sub-threshold intensity of 2 µW/μm² were generated. At spacing of 50 µm, the median excitation probability increases compared to single spot stimulation with the same intensity.

Proceedings Article | 1 April 2020 Presentation

Force spectroscopy measurements of ligand binding with transmembrane proteins using optical tweezers (Conference Presentation)

Carolin Riesenberg, Christian Alejandro Iriarte Valdez, Annegret Becker, Alexander Heisterkamp, Anaclet Ngezahayo, Maria Leilani Torres-Mapa

Proceedings Volume 11359, 1135915 (2020) https://doi.org/10.1117/12.2555811

KEYWORDS: Optical tweezers, Proteins, Spectroscopy, Particles, Receptors, Calibration, Feedback control, Silica, Laser optics, Thermodynamics

Read Abstract +

Proceedings Article | 1 April 2020 Presentation

Integration of optical manipulation in 3D printed microfluidic devices (Conference Presentation)

Haoran Wang, Anton Enders, Alexander Heisterkamp, Janina Bahnemann, Maria Leilani Torres-Mapa

Proceedings Volume 11359, 1135916 (2020) https://doi.org/10.1117/12.2555949

Read Abstract +

Microfluidic systems facilitate the realization of compact and miniaturized lab-on-a-chip systems which can be used for various applications. The conventional method to fabricate such devices entails the use of complex etching processes in clean rooms and soft lithography methods which require substantial expertise. Since the design of such microfluidic devices is often customized depending on the application of the user, it would be ideal to have a fabrication technique that would allow for fast and reliable production with the possibility to generate high resolution three-dimensional structures using different materials. 3D printing technique has been recently demonstrated as a means to fabricate microfluidic devices. It enables rapid prototyping of robust and complex structures. Nowadays, 3D printers can create small structures down to several tens of microns. 3D-printed devices can also provide lab-on-a-chip systems which are compatible with optical techniques and microscopy. In this work, we demonstrate the integration of optical manipulation in 3D-printed microfluidic systems with particular focus on optimized design and fabrication protocol. 3D printing was performed using a Multijet printer (MJP2500 Plus). A microfluidic chip was designed for the purpose of dual beam optical trapping and optical stretching of mammalian cells. Three inlets with channel dimensions of 500 µm were used to flow buffer, particles or cells into the device. Two single mode fibers were inserted into fiber guide channels with dimensions of 500 µm, separated with a distance of 300 µm, in order to deliver counterpropagating beams into the trapping region. Hydrodynamic focusing was performed showing that laminar flow can be achieved in the device. In order to evaluate the compatibility of 3D-printed microfluidic chips for optical manipulation, the mean square displacement of the optically trapped 10 µm polystyrene particle was measured for different laser powers. In addition, we demonstrate optical stretching4 of microvascular endothelial cells under flow.

Proceedings Article | 19 February 2020 Presentation + Paper

Design of a novel MEMS based laser scanning laryngoscope to combine high precision laser cuts with simultaneous MHz OCT and stereo camera feedback

James Napier, Sontje Ihler, Max-Heinrich Laves, Miroslav Zabic, Alexander Heisterkamp, Walter Neu

Proceedings Volume 11213, 112130J (2020) https://doi.org/10.1117/12.2550806

KEYWORDS: Laser cutting, Optical coherence tomography, Microelectromechanical systems, Surgery, Laser therapeutics, Fiber lasers, Scanners, Zemax, Laser scanners

Read Abstract +

Proceedings Article | 19 February 2020 Paper

Evaluation of a model for deep tissue optogenetic stimulation

Sonja Johannsmeier, Johannes Wenzel, Maria Torres-Mapa, Sebastian Junge, Philipp Sasse, Tammo Ripken, Dag Heinemann, Alexander Heisterkamp

Proceedings Volume 11227, 1122708 (2020) https://doi.org/10.1117/12.2544837

KEYWORDS: Tissues, Tissue optics, Optogenetics, Data modeling, Scattering, Light scattering, Diffusion, Absorption, Photons

Read Abstract +

Proceedings Article | 22 July 2019 Paper

Hydrogels for light delivery in in vivo optogenetic applications

Sonja Johannsmeier, Maria Torres-Mapa, Tammo Ripken, Dag Heinemann, Alexander Heisterkamp

Proceedings Volume 11075, 110750H (2019) https://doi.org/10.1117/12.2525324

KEYWORDS: Optogenetics, Particles, Waveguides, In vivo imaging, Tissues, Tissue optics, Refractive index, Natural surfaces, Reflection, Collagen

Read Abstract +

Proceedings Article | 26 February 2019 Paper

Concept for high speed vocal cord imaging with swept-source optical coherence tomography

Miroslav Zabic, Sara Sharifpourboushehri, Lennart Müller-Wirts, Hannes Benecke, Alexander Heisterkamp, Heiko Meyer, Tammo Ripken

Proceedings Volume 10853, 108530H (2019) https://doi.org/10.1117/12.2509538

KEYWORDS: Optical coherence tomography, Signal processing, Software development, Optical simulations, Liquid lenses, Optical imaging

Read Abstract +

Proceedings Article | 20 February 2019 Paper

Wavefront sensorless adaptive optics for optical coherence tomography guided femtosecond laser surgery in the posterior eye

Miroslav Zabic, Ben Matthias, Jan Hahn, Alexander Heisterkamp, Heiko Meyer, Tammo Ripken

Proceedings Volume 10886, 1088603 (2019) https://doi.org/10.1117/12.2509363

KEYWORDS: Adaptive optics, Wavefronts, Optical coherence tomography, Sensors, Deformable mirrors, Laser optics, Optimization (mathematics), Eye

Read Abstract +

Proceedings Article | 24 May 2018 Presentation

Hydrogels for efficient light delivery in optogenetic applications (Conference Presentation)

Sonja Johannsmeier, Maria Leilani Torres, Tammo Ripken, Dag Heinemann, Alexander Heisterkamp

Proceedings Volume 10685, 106851C (2018) https://doi.org/10.1117/12.2306425

KEYWORDS: Optogenetics, Waveguides, Tissues, Tissue optics, Proteins, Biomedical optics, Robotics, Biotechnology, Interfaces, Refractive index

Read Abstract +

Optogenetics utilizes light sensitive proteins to trigger biological functions by an external optical stimulus. It has been applied in numerous settings, including robotics, biotechnology, and several therapeutic approaches. The latter is of particular interest, as optogenetics provides the possibility to directly control cellular functions of excitable tissues, such as neurons and muscles, in a contact free manner by ion channels such as channelrhodopsin-2. In this context, optogenetics allows to create a human-implant interface, with an unprecedented performance. However, optogenetic therapeutic approaches are inhibited two conceptual constraints, limiting their clinical translation. (1) Precise and defined delivery of the stimulation light is restricted by scattering and absorption of the body’s tissue, limiting its resolution and thereby selectivity. (2) Optogenetics implies intrinsically a gene modification of the target tissue, raising issues concerning the effective in vivo delivery and the safety of the (viral) vectors applied. Biocompatible waveguides which in parallel can serve as cell encapsulation could provide a promising approach to circumvent these constraints. Encapsulation would ensure optical accessibility and encase the genetically modified cells. These constructs should guide and distribute the light as desired with minimal losses and they should also mimic the mechanical properties of the surrounding tissue to ensure compatibility and long-term stability. In this project, we present a study on poly(ethylene glycol) (PEGDA) based hydrogels as waveguides for optogenetic pacing of the heart. PEGDA is a non-biodegradable, biocompatible polymer with high transparency for visible wavelengths. Both optical and mechanical properties of hydrogels made from PEGDA derivatives are tuned to achieve compatibility with muscle tissue as well as optimal light guiding and distribution. The excitation light is coupled into the hydrogel with a biocompatible fiber. The design of the fiber-hydrogel contact must ensure efficient light coupling as well as mechanically stable binding of the fiber to the hydrogel construct. Properties of the hydrogel are mainly tuned by monomer length and concentration. Total internal reflection can be achieved by embedding a fiber-like hydrogel with a high refractive index into a second, low refractive index gel. Multi-component gels and different geometries are explored as additional ways to impact light distribution. After optimization, the hydrogel may be used to deliver light for the excitation of genetically altered cardiomyocytes for controlled contraction. This would pave the way for the development of a biohybrid, optogenetically driven pacemaker implant. On a long term perspective, hydrogel waveguides with embedded optogenetic excitable cells which functionally couple to the target tissue may serve as a general human-implant interface, with encased genetic modification and controlled, biocompatible light guiding to the target tissue.

Proceedings Article | 14 March 2018 Presentation

Intracellular cargo delivery with polymer substrates and nanosecond pulsed laser (Conference Presentation)

Weilu Shen, Stefan Kalies, Nabiha Saklayen, Marinna Madrid, Alexander Heisterkamp, Eric Mazur

Proceedings Volume 10522, 105220C (2018) https://doi.org/10.1117/12.2289012

KEYWORDS: Polymers, Pulsed laser operation, Ultrafast lasers, Plasma, Fabrication, Luminescence, Flow cytometry, Molecules, Scanning electron microscopy, Natural surfaces

Read Abstract +

Proceedings Article | 23 February 2018 Paper

Investigation of second harmonic generation and multispectral imaging as new contrast mechanisms in scanning laser optical tomography

Lena Nolte, Georgios Antonopoulos, Alexander Heisterkamp, Tammo Ripken, Heiko Meyer

Proceedings Volume 10499, 1049913 (2018) https://doi.org/10.1117/12.2289509

KEYWORDS: Second-harmonic generation, Luminescence, Polarization, Multispectral imaging, Laser optics, Optical tomography, Harmonic generation, Absorption, Scattering, Radon transform

Read Abstract +

Proceedings Article | 14 February 2018 Paper

Hydrogels for efficient light delivery in optogenetic applications

S. Johannsmeier, M. Torres, T. Ripken, D. Heinemann, A. Heisterkamp

Proceedings Volume 10482, 104820Q (2018) https://doi.org/10.1117/12.2289470

KEYWORDS: Tissues, Optogenetics, Heart, Particles, Refractive index, Waveguides, Light scattering, Polymerization

Read Abstract +

Proceedings Article | 1 August 2017 Paper

Gold nanoparticle-mediated laser stimulation causes a complex stress signal in neuronal cells

Sonja Johannsmeier, Patrick Heeger, Mitsuhiro Terakawa, Stefan Kalies, Alexander Heisterkamp, Tammo Ripken, Dag Heinemann

Proceedings Volume 10417, 104170B (2017) https://doi.org/10.1117/12.2284174

KEYWORDS: Gold, Nanoparticles

Read Abstract +

Proceedings Article | 26 June 2017 Paper

Holographically generated structured illumination for cell stimulation in optogenetics

Felix Schmieder, Lars Büttner, Jürgen Czarske, Maria Leilani Torres, Alexander Heisterkamp, Simon Klapper, Volker Busskamp

Proceedings Volume 10335, 1033517 (2017) https://doi.org/10.1117/12.2270281

KEYWORDS: Digital holography, Holography, Optogenetics, Computer generated holography, Spatial light modulators, Holograms, Action potentials, Ferroelectric LCDs, Silicon

Read Abstract +

Proceedings Article | 21 April 2017 Presentation

Photothermal gold nanoparticle mediated stimulation of cardiomyocyte beating (Conference Presentation)

Stefan Kalies, Lara Gentemann, Michelle Coffee, Robert Zweigerdt, Dag Heinemann, Alexander Heisterkamp

Proceedings Volume 10094, 100940J (2017) https://doi.org/10.1117/12.2249834

KEYWORDS: Light emitting diodes, Gold, Nanoparticles, Calcium, Laser systems engineering, Laser irradiation, Molecular lasers, Picosecond phenomena, Particles, Stem cells

Read Abstract +

Proceedings Article | 19 April 2017 Presentation

Optical cell stimulation for neuronal excitation (Conference Presentation)

Sonja Johannsmeier, Patrick Heeger, Mitsuhiro Terakawa, Alexander Heisterkamp, Tammo Ripken, Dag Heinemann

Proceedings Volume 10052, 100520E (2017) https://doi.org/10.1117/12.2252017

KEYWORDS: Picosecond phenomena, Calcium, Gold, Nanoparticles, Optogenetics, Signal detection, Optical manipulation, Modulation, Action potentials, Biomedical optics

Read Abstract +

SPIE Journal Paper | 9 May 2016 Open Access

Biodegradable microsphere-mediated cell perforation in microfluidic channel using femtosecond laser

Atsuhiro Ishii, Kazumasa Ariyasu, Tatsuki Mitsuhashi, Dag Heinemann, Alexander Heisterkamp, Mitsuhiro Terakawa

JBO, Vol. 21, Issue 05, 055001, (May 2016) https://doi.org/10.1117/12.10.1117/1.JBO.21.5.055001

KEYWORDS: Microfluidics, Femtosecond phenomena, Luminescence, Laser applications, Pulsed laser operation, Molecules, Polymers, Molecular lasers, Particles, Silica

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 1 March 2016 Presentation + Paper

Signal and response properties indicate an optoacoustic effect underlying the intra-cochlear laser-optical stimulation

Nicole Kallweit, Peter Baumhoff, Alexander Krueger, Nadine Tinne, Alexander Heisterkamp, Andrej Kral, Hannes Maier, Tammo Ripken

Proceedings Volume 9689, 96892G (2016) https://doi.org/10.1117/12.2210926

KEYWORDS: Pulsed laser operation, Laser optics, Signal attenuation, Absorption, Infrared radiation, Sensors, Neurons, Acoustics, Water, Laser systems engineering, In vivo imaging, Signal detection

Read Abstract +

Proceedings Article | 29 February 2016 Paper

Three-dimensional imaging of intracochlear tissue by scanning laser optical tomography (SLOT)

N. Tinne, L. Nolte, G. Antonopoulos, J. Schulze, J. Andrade, A. Heisterkamp, H. Meyer, A. Warnecke, O. Majdani, T. Ripken

Proceedings Volume 9689, 96892H (2016) https://doi.org/10.1117/12.2211066

KEYWORDS: Optical tomography, Laser optics, Ear, Tomography, Microscopy, Visualization, 3D image processing, Optical clearing, Absorption, Luminescence, Light scattering, 3D scanning

Read Abstract +

Proceedings Article | 5 March 2015 Paper

Four-wave mixing microscopy: a high potential nonlinear imaging method

Tobias Ehmke, Andreas Knebl, Alexander Heisterkamp

Proceedings Volume 9329, 932912 (2015) https://doi.org/10.1117/12.2076743

KEYWORDS: Four wave mixing, Signal detection, Microscopy, Objectives, Optical parametric oscillators, Microscopes, Signal processing, Signal generators, In vivo imaging, Tissues

Read Abstract +

Proceedings Article | 7 March 2014 Paper

Femtosecond optical injection of intact plant cells using a reconfigurable platform

Claire Mitchell, Stefan Kalies, Tomas Cizmar, Nicola Bellini, Anisha Kubasik-Thayil, Alexander Heisterkamp, Lesley Torrance, Alison Roberts, Frank Gunn-Moore, Kishan Dholakia

Proceedings Volume 8972, 89720C (2014) https://doi.org/10.1117/12.2037784

KEYWORDS: Bessel beams, Femtosecond phenomena, Gaussian beams, Pulsed laser operation, Molecules, Luminescence, Biomedical optics, Laser beam propagation, Microscopes, Laser optics

Read Abstract +

Proceedings Article | 15 March 2013 Paper

High-throughput optical injection of mammalian cells using a non-diffracting beam in a microfluidic platform

Helen Rendall, Robert Marchington, Bavishna Praveen, Gerald Bergmann, Yoshihiko Arita, Alexander Heisterkamp, Frank Gunn-Moore, Kishan Dholakia

Proceedings Volume 8611, 861103 (2013) https://doi.org/10.1117/12.2003193

KEYWORDS: Microfluidics, Bessel beams, Femtosecond phenomena, Electroluminescence, Biomedical optics, Neodymium, Capillaries, Nondiffracting beams, Digital image correlation, Astronomical imaging

Read Abstract +

Proceedings Article | 8 March 2013 Paper

Imaging of the mouse lung with scanning laser optical tomography (SLOT)

Marko Heidrich, Manuela Kellner, Rebecca Beigel, Raoul-Amadeus Lorbeer, Lars Knudsen, Alexander Heisterkamp, Tammo Ripken, Matthias Ochs, Mark Kühnel, Heiko Meyer

Proceedings Volume 8565, 856535 (2013) https://doi.org/10.1117/12.2003955

KEYWORDS: Lung, Blood vessels, Visualization, Laser optics, Optical tomography, Microscopy, Image transmission, Tissue optics, Absorption, Optical resolution

Read Abstract +

Proceedings Article | 22 September 2011 Paper

Spatial beam shaping for lowering the threshold energy for femtosecond laser pulse photodisruption

Anja Hansen, Tammo Ripken, Alexander Heisterkamp

Proceedings Volume 8130, 81300M (2011) https://doi.org/10.1117/12.900598

KEYWORDS: Adaptive optics, Eye, Wavefronts, Femtosecond phenomena, Eye models, Tissues, Pulsed laser operation, Retina, Laser damage threshold, Surgery

Read Abstract +

SPIE Journal Paper | 1 August 2011 Open Access

Femtosecond laser-induced fusion of nonadherent cells and two-cell porcine embryos

Kai Kuetemeyer, Alexander Heisterkamp, Andrea Lucas-Hahn, Björn Petersen, Heiner Niemann

JBO, Vol. 16, Issue 08, 088001, (August 2011) https://doi.org/10.1117/12.10.1117/1.3609818

KEYWORDS: Laser welding, Femtosecond phenomena, Fusion energy, Laser damage threshold, Laser therapeutics, Laser irradiation, Objectives, Data fusion, Control systems, Pulsed laser operation

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 8 June 2011 Paper

Interaction dynamics of fs-laser induced cavitation bubbles and their impact on the laser-tissue-interaction of modern ophthalmic laser systems

N. Tinne, T. Ripken, H. Lubatschowski, A. Heisterkamp

Proceedings Volume 8092, 80921H (2011) https://doi.org/10.1117/12.889341

KEYWORDS: Cavitation, Laser tissue interaction, Laser vision correction, Laser cutting, Pulsed laser operation, Laser energy, Tissue optics, Fusion energy, Laser systems engineering, Laser therapeutics

Read Abstract +

A today well-known laser based treatment in ophthalmology is the LASIK procedure which nowadays includes cutting of the corneal tissue with ultra-short laser pulses. Instead of disposing a microkeratome for cutting a corneal flap, a focused ultra-short laser pulse is scanned below the surface of biological tissue causing the effect of an optical breakdown and hence obtaining a dissection. Inside the tissue, the energy of the laser pulses is absorbed by non-linear processes; as a result a cavitation bubble expands and ruptures the tissue. Hence, positioning of several optical breakdowns side by side generates an incision. Due to a reduction of the amount of laser energy, with a moderate duration of treatment at the same time, the current development of ultra-short pulse laser systems points to higher repetition rates in the range of even Megahertz instead of tens or hundreds of Kilohertz. In turn, this results in a pulse overlap and therefor a probable occurrence of interaction between different optical breakdowns and respectively cavitation bubbles of adjacent optical breakdowns. While the interaction of one single laser pulse with biological tissue is analyzed reasonably well experimentally and theoretically, the interaction of several spatial and temporal following pulses is scarcely determined yet. Thus, the aim of this study is to analyse the dynamic and interaction of two cavitation bubbles by using high speed photography. The applied laser pulse energy, the energy ratio and the spot distance between different cavitation bubbles were varied. Depending on a change of these parameters different kinds of interactions such as a flattening and deformation of bubble shape or jet formation are observed. The effects will be discussed regarding the medical ophthalmic application of fs-lasers. Based on these results a further research seems to be inevitable to comprehend and optimize the cutting effect of ultra-short pulse laser systems with high (> 500 kHz) repetition rates.

Proceedings Article | 8 June 2011 Paper

Focal spot shaping for femtosecond laser pulse photodisruption through turbid media

Anja Hansen, Tammo Ripken, Alexander Heisterkamp

Proceedings Volume 8092, 80921E (2011) https://doi.org/10.1117/12.889310

KEYWORDS: Adaptive optics, Eye, Femtosecond phenomena, Wavefronts, Eye models, Retina, Surgery, Pulsed laser operation, Tissue optics, Optical calibration

Read Abstract +

Proceedings Article | 11 February 2011 Paper

Gold nanoparticle mediated cell manipulation using fs and ps laser pulses for cell perforation and transfection

D. Heinemann, M. Schomaker, D. Motekaitis, J. Krawinkel, D. Killian, H. Escobar, Christian Junghanß, Alexander Heisterkamp

Proceedings Volume 7925, 79250J (2011) https://doi.org/10.1117/12.874904

KEYWORDS: Picosecond phenomena, Molecules, Gold, Particles, Nanoparticles, Molecular lasers, Radiation effects, Femtosecond phenomena, Molecular biology, Pulsed laser operation

Read Abstract +

Proceedings Article | 11 February 2011 Paper

Mechanisms of gold nanoparticle mediated ultrashort laser cell membrane perforation

M. Schomaker, J. Baumgart, D. Motekaitis, D. Heinemann, J. Krawinkel, M. Pangalos, W. Bintig, E. Boulais, R. Lachaine, B. St.-Louis Lalonde, A. Ngezahayo, M. Meunier, A. Heisterkamp

Proceedings Volume 7925, 79250F (2011) https://doi.org/10.1117/12.876625

KEYWORDS: Cavitation, Picosecond phenomena, Pulsed laser operation, Particles, Gold, Nanoparticles, Molecules, Laser therapeutics, Laser systems engineering, Femtosecond phenomena

Read Abstract +

Proceedings Article | 8 February 2011 Paper

Mechanisms of femtosecond laser cell surgery in the low-density plasma regime

K. Kuetemeyer, R. Rezgui, H. Lubatschowski, A. Heisterkamp

Proceedings Volume 7897, 789704 (2011) https://doi.org/10.1117/12.874147

KEYWORDS: Laser ablation, Surgery, Plasma, Femtosecond phenomena, Ionization, Laser therapeutics, Molecules, Laser damage threshold, Luminescence, Laser vision correction

Read Abstract +

SPIE Journal Paper | 1 September 2010 Open Access

Errata: Repetition rate dependency of reactive oxygen species formation during femtosecond laser-based cell surgery

Judith Baumgart, Kai Kuetemeyer, Holger Lubatschowski, Alexander Heisterkamp, Willem Bintig, Anaclet Ngezahayo, Wolfgang Ertmer

JBO, Vol. 15, Issue 05, 059802, (September 2010) https://doi.org/10.1117/12.10.1117/1.3497003

KEYWORDS: Oxygen, Femtosecond phenomena, Laser therapeutics, Surgery, Laser vision correction, Biophysics, Quantum optics

DOWNLOAD PAPER

Proceedings Article | 28 August 2010 Paper

Ultrashort laser pulse cell manipulation using nano- and micro- materials

Markus Schomaker, Doreen Killian, Saskia Willenbrock, Eric Diebold, Eric Mazur, Willem Bintig, Anaclet Ngezahayo, Ingo Nolte, Hugo Murua Escobar, Christian Junghanß, Holger Lubatschowski, Alexander Heisterkamp

Proceedings Volume 7762, 77623G (2010) https://doi.org/10.1117/12.869054

KEYWORDS: Molecules, Green fluorescent protein, Femtosecond phenomena, Particles, Glasses, Nanoparticles, Luminescence, Ultrafast phenomena, Molecular lasers, Stem cells

Read Abstract +

SPIE Journal Paper | 1 July 2010 Open Access

Combined multiphoton imaging and automated functional enucleation of porcine oocytes using femtosecond laser pulses

Kai Kuetemeyer, Andrea Lucas-Hahn, Björn Petersen, Erika Lemme, Petra Hassel, Heiner Niemann, Alexander Heisterkamp

JBO, Vol. 15, Issue 04, 046006, (July 2010) https://doi.org/10.1117/12.10.1117/1.3463012

KEYWORDS: Laser ablation, Femtosecond phenomena, Luminescence, Multiphoton microscopy, Control systems, Imaging systems, 3D image processing, Pulsed laser operation, Laser systems engineering, Ultraviolet radiation

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 3 March 2010 Paper

Visualizing of fs laser pulse induced micro-incisions inside crystalline lens tissue

O. Stachs, S. Schumacher, M. Kröger, H. Hoffmann, M. Fromm, A. Heisterkamp, H. Lubatschowski, R. Guthoff

Proceedings Volume 7550, 75500U (2010) https://doi.org/10.1117/12.841584

KEYWORDS: Optical fibers, Laser tissue interaction, Femtosecond phenomena, Visualization, Crystals, Confocal microscopy, Laser cutting, Tissues, Laser crystals, Microscopes

Read Abstract +

Proceedings Article | 3 March 2010 Paper

Three-dimensional multimodal microscopy of rabbit cornea after cross-linking treatment

A. Krüger, M. Hovakimyan, D. Ramírez, R.-A. Lorbeer, M. Kröger, O. Stachs, A. Wree, R. Guthoff, H. Lubatschowski, A. Heisterkamp

Proceedings Volume 7550, 755002 (2010) https://doi.org/10.1117/12.842282

KEYWORDS: Second-harmonic generation, Cornea, Confocal microscopy, Microscopy, Reflectivity, Collagen, Femtosecond phenomena, Visualization, Two photon excitation microscopy, Luminescence

Read Abstract +

Proceedings Article | 25 February 2010 Paper

Functional enucleation of porcine oocytes for somatic cell nuclear transfer using femtosecond laser pulses

K. Kuetemeyer, A. Lucas-Hahn, B. Petersen, P. Hassel, E. Lemme, H. Niemann, A. Heisterkamp

Proceedings Volume 7589, 75890A (2010) https://doi.org/10.1117/12.840045

KEYWORDS: Femtosecond phenomena, Laser ablation, Multiphoton microscopy, Luminescence, Genetics, 3D image processing, Laser systems engineering, Pulsed laser operation, Imaging systems, Microscopes

Read Abstract +

Proceedings Article | 25 February 2010 Paper

Fs-laser cell perforation using gold nanoparticles of different shapes

Markus Schomaker, Holger Fehlauer, Willem Bintig, Anaclet Ngezahayo, Ingo Nolte, Hugo Murua Escobar, Holger Lubatschowski, Alexander Heisterkamp

Proceedings Volume 7589, 75890C (2010) https://doi.org/10.1117/12.842446

KEYWORDS: Nanoparticles, Gold, Femtosecond phenomena, Particles, Molecules, Laser therapeutics, Spherical lenses, Green fluorescent protein, Stem cells, Multiphoton microscopy

Read Abstract +

Proceedings Article | 24 February 2010 Paper

Applying optical Fourier filtering to standard optical projection tomography

Raoul-Amadeus Lorbeer, Heiko Meyer, Marko Heidrich, Holger Lubatschowski, Alexander Heisterkamp

Proceedings Volume 7570, 75700F (2010) https://doi.org/10.1117/12.841599

KEYWORDS: Modulation transfer functions, Bessel beams, Tomography, Projection systems, Optical tomography, Microscopy, Luminescence, Nerve, Optical filters, Image resolution

Read Abstract +

Proceedings Article | 20 February 2010 Paper

In vivo optical coherence tomography of percutaneous implants in hairless mice

S. Donner, F. Witte, I. Bartsch, F. Petraglia, O. Massow, M. Heidrich, H. Lubatschowski, A. Heisterkamp, A. Krüger

Proceedings Volume 7554, 75540S (2010) https://doi.org/10.1117/12.841640

KEYWORDS: Optical coherence tomography, Tissues, In vivo imaging, Interfaces, Skin, Inflammation, Tissue optics, Biopsy, Mirrors, Animal model studies

Read Abstract +

Proceedings Article | 8 February 2010 Paper

Optical forces in biophotonics: transfection and cell sorting

Wolfgang Ertmer, Heiko Meyer, Raoul Lorbeer, Gerald Bergmann, Christina Krämer, Holger Lubatschowski, Hugo Murua Escoboar, Ingo Nolte, Alexander Heisterkamp

Proceedings Volume 7613, 76130Q (2010) https://doi.org/10.1117/12.841868

KEYWORDS: Microfluidics, Microscopes, Molecules, Luminescence, Biomedical optics, Ultrafast phenomena, Optical tweezers, Pulsed laser operation, Molecular lasers, Absorption

Read Abstract +

SPIE Journal Paper | 1 September 2009 Open Access

Repetition rate dependency of reactive oxygen species formation during femtosecond laser-based cell surgery

Judith Baumgart, Kai Kuetemeyer, Willem Bintig, Anaclet Ngezahayo, Wolfgang Ertmer, Holger Lubatschowski, Alexander Heisterkamp

JBO, Vol. 14, Issue 05, 054040, (September 2009) https://doi.org/10.1117/12.10.1117/1.3253382

KEYWORDS: Luminescence, Molecules, Oxygen, Surgery, Femtosecond phenomena, Laser therapeutics, Laser irradiation, Pulsed laser operation, Laser vision correction, Multiphoton microscopy

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 17 July 2009 Paper

Femtosecond laser based enucleation of porcine oocytes for somatic cell nuclear transfer

K. Kütemeyer, A. Lucas-Hahn, B. Petersen, P. Hassel, E. Lemme, H. Niemann, A. Heisterkamp

Proceedings Volume 7373, 73730C (2009) https://doi.org/10.1117/12.831880

KEYWORDS: Femtosecond phenomena, Multiphoton microscopy, Ultrafast phenomena, Laser ablation, Luminescence, 3D image processing, Molecules, Laser therapeutics, Absorption, Microscopes

Read Abstract +

Proceedings Article | 17 July 2009 Paper

Nanoparticle mediated laser cell perforation

Markus Schomaker, Judith Baumgart, Anaclet Ngezahayo, Jörn Bullerdiek, Ingo Nolte, Hugo Murua-Escobar, Holger Lubatschowski, Alexander Heisterkamp

Proceedings Volume 7373, 737308 (2009) https://doi.org/10.1117/12.831903

KEYWORDS: Nanoparticles, Gold, Particles, Femtosecond phenomena, Molecules, Multiphoton microscopy, Laser therapeutics, Proteins, Laser marking, Stem cells

Read Abstract +

Proceedings Article | 1 July 2009 Paper

Three dimensional numerical simulation of complex optical systems using the coherenttransfer function

Raoul-Amadeus Lorbeer, Alexander Heisterkamp

Proceedings Volume 7367, 73671K (2009) https://doi.org/10.1117/12.831529

KEYWORDS: Polarization, Confocal microscopy, Objectives, Microscopy, Contrast transfer function, Numerical simulations, Computer simulations, Point spread functions, Optical transfer functions, Femtosecond phenomena

Read Abstract +

Proceedings Article | 1 July 2009 Paper

Reflective confocal laser scanning microscopy and nonlinear microscopy of cross-linked rabbit cornea

Alexander Krueger, Marina Hovakimyan, Diego Ramirez, Oliver Stachs, Rudolf Guthoff, Alexander Heisterkamp

Proceedings Volume 7367, 736719 (2009) https://doi.org/10.1117/12.831478

KEYWORDS: Cornea, Second-harmonic generation, Reflectivity, Confocal microscopy, Microscopy, Scanning helium ion microscopy, Collagen, Signal detection, Wound healing, Confocal laser scanning microscopy

Read Abstract +

Proceedings Article | 18 February 2009 Paper

Plasmonic perforation of living cells using ultrashort laser pulses and gold nanoparticles

Markus Schomaker, Judith Baumgart, Anaclet Ngezahayo, Jörn Bullerdiek, Ingo Nolte, Hugo Murua Escobar, Holger Lubatschowski, Alexander Heisterkamp

Proceedings Volume 7192, 71920U (2009) https://doi.org/10.1117/12.809316

KEYWORDS: Nanoparticles, Gold, Particles, Proteins, Plasmons, Femtosecond phenomena, Green fluorescent protein, Luminescence, Plasmonics, Ultrafast phenomena

Read Abstract +

Proceedings Article | 20 February 2008 Paper

Investigation of reactive oxygen species formation in living cells during femtosecond laser based cell surgery

J. Baumgart, W. Bintig, A. Ngezahayo, W. Ertmer, H. Lubatschowski, A. Heisterkamp

Proceedings Volume 6854, 68540O (2008) https://doi.org/10.1117/12.763315

KEYWORDS: Luminescence, Surgery, Oxygen, Femtosecond phenomena, Laser therapeutics, Pulsed laser operation, Laser irradiation, Molecular lasers, Laser energy, Laser vision correction

Read Abstract +

Proceedings Article | 15 February 2008 Paper

Numerical modeling of nonlinear plasma formation in high-NA micromachining of transparent materials and biological cells using ultrashort laser pulses

C. Arnold, A. Heisterkamp, W. Ertmer, H. Lubatschowski

Proceedings Volume 6881, 688104 (2008) https://doi.org/10.1117/12.761206

KEYWORDS: Plasma, Ultrafast phenomena, Plasma generation, Ionization, Electrons, Nonlinear optics, Absorption, Surgery, Soft tissue optics, Tissue optics

Read Abstract +

Ultrashort laser pulses recently found extensive application in micro- and nanostructuring, in refractive surgery of the eye, and in biophotonics. Due to the high laser intensity required to induce optical breakdown, nonlinear plasma formation is generally accompanied by a number of undesired nonlinear side-effects such as self-focusing, filamentation and plasma-defocusing, seriously limiting achievable precision and reproducibility. To reduce pulse energy, enhance precision, and limit nonlinear side effects, applications of ultrashort pulses have recently evolved towards tight focusing using high numerical aperture microscope objectives. However, from the theoretical and numerical point of view generation of optical breakdown at high numerical aperture focusing was barely studied. To simulate the interaction of ultrashort laser pulses with transparent materials, a comprehensive numerical model taking into account nonlinear propagation, plasma generation as well as the pulse's interaction with the generated plasma is introduced. By omitting the widely used scalar and paraxial approximations a novel nonlinear propagation equation is derived, especially suited to meet the conditions of high numerical aperture focusing. The multiple rate equation (MRE) model is used to simultaneously calculate the generation of free electrons. Nonparaxial and vectorial diffraction theory provides initial conditions. The theoretical model derived is applied to numerically study the generation of optical breakdown plasmas, concentrating on parameters usually found in experimental applications of cell surgery. Water is used as a model substance for biological soft tissue and cellular constituents. For focusing conditions of numerical aperture NA < 0.9 generation of optical breakdown is shown to be strongly influenced by plasma defocusing, resulting in spatially distorted breakdown plasmas of expanded size. For focusing conditions of numerical aperture NA ≥ 0.9 on the other hand generation of optical breakdown is found to be almost unaffected by distortive side-effects, perfectly suited for material manipulation of highest precision.

Proceedings Article | 6 February 2007 Paper

Live cell opto-injection by femtosecond laser pulses

J. Baumgart, W. Bintig, W. Ertmer, H. Lubatschowski, A. Heisterkamp

Proceedings Volume 6435, 643512 (2007) https://doi.org/10.1117/12.700166

KEYWORDS: Luminescence, Femtosecond phenomena, Proteins, Microscopes, Fluorescent proteins, Microscopy, Green fluorescent protein, Viruses, Cell death, Tissues

Read Abstract +

Proceedings Article | 28 February 2006 Paper

Multiphoton microscopy for cell surgery

J. Baumgart, A. Heisterkamp, A. Ngezahayo, W. Ertmer, H. Lubatschowski

Proceedings Volume 6108, 61081B (2006) https://doi.org/10.1117/12.645699

KEYWORDS: Luminescence, Retina, Absorption, Multiphoton microscopy, Tissues, Tissue optics, Surgery, Femtosecond phenomena, Eye, Laser ablation

Read Abstract +

Proceedings Article | 15 April 2005 Paper

Nanosurgery in live cells using ultrashort laser pulses

Alexander Heisterkamp, Iva Maxwell, Sanjay Kumar, J. Underwood, J. Nickerson, Donald Ingber, Eric Mazur

Proceedings Volume 5695, (2005) https://doi.org/10.1117/12.590467

KEYWORDS: Luminescence, Laser ablation, Laser cutting, Ultrafast phenomena, Transmission electron microscopy, Microscopy, Femtosecond phenomena, Microscopes, Electron microscopy, Biology

Read Abstract +

Proceedings Article | 21 March 2005 Paper

Numerical calculation of nonlinear ultrashort laser pulse propagation in transparent Kerr media

Cord Arnold, Alexander Heisterkamp, Wolfgang Ertmer, Holger Lubatschowski

Proceedings Volume 5714, (2005) https://doi.org/10.1117/12.588903

KEYWORDS: Electrons, Ionization, Plasma, Tissue optics, Ultrafast phenomena, Refractive index, Absorption, Cornea, Plasma generation, Water

Read Abstract +

Proceedings Article | 13 July 2004 Paper

Investigations for the correction of presbyopia by-fs-laser induced cuts

Tammo Ripken, Uwe Oberheide, Alexander Heisterkamp, Wolfgang Ertmer, Georg Gerten, Holger Lubatschowski

Proceedings Volume 5314, (2004) https://doi.org/10.1117/12.528955

KEYWORDS: Laser cutting, Tissues, Laser tissue interaction, Femtosecond phenomena, Eye, Cornea, Tissue optics, Glasses, Light scattering, Scanners

Read Abstract +

Proceedings Article | 1 June 2004 Paper

Numerical calculation of nonlinear ultrashort laser pulse propagation in water

Cord Arnold, Alexander Heisterkamp, Wolfgang Ertmer, Holger Lubatschowski

Proceedings Volume 5340, (2004) https://doi.org/10.1117/12.529003

KEYWORDS: Electrons, Tissue optics, Ultrafast phenomena, Ionization, Cornea, Water, Refractive index, Diffraction, Plasma, Dispersion

Read Abstract +

Proceedings Article | 16 October 2003 Paper

Applications of ultrafast lasers in ophthalmology

Alexander Heisterkamp, Tammo Ripken, Uwe Oberheide, Omid Kermani, Thanongsak Mamom, Wolfgang Drommer, Wolfgang Ertmer, Holger Lubatschowski

Proceedings Volume 5142, (2003) https://doi.org/10.1117/12.500612

KEYWORDS: Eye, Cornea, Surgery, Laser cutting, Tissues, Laser vision correction, Laser therapeutics, Ultrafast lasers, Ophthalmology, Wound healing

Read Abstract +

Proceedings Article | 16 October 2003 Paper

First in-vivo studies of presbyopia treatment with ultrashort laser pulses

Tammo Ripken, Alexander Heisterkamp, Uwe Oberheide, Ron Krueger, Elke Luetkefels, Wolfgang Drommer, Wolfgang Ertmer, Holger Lubatschowski

Proceedings Volume 5142, (2003) https://doi.org/10.1117/12.500421

KEYWORDS: Laser cutting, Eye, In vivo imaging, Cornea, Tissue optics, Laser tissue interaction, Femtosecond phenomena, Optical fibers, Laser therapeutics, Tissues

Read Abstract +

Proceedings Article | 19 February 2003 Paper

Medical and biological applications for ultrafast laser pulses

Holger Lubatschowski, Alexander Heisterkamp, Fabian Will, Ajoy Singh, Jesper Serbin, Andreas Ostendorf, Omid Kermani, R. Heermann, Herbert Welling, Wolfgang Ertmer

Proceedings Volume 4830, (2003) https://doi.org/10.1117/12.486505

KEYWORDS: Laser tissue interaction, Tissues, Laser ablation, Femtosecond phenomena, Laser dentistry, Cornea, Pulsed laser operation, Laser vision correction, Surgery, Laser cutting

Read Abstract +

Proceedings Article | 13 June 2002 Paper

Intrastromal refractive sugery with ultrashort laser pulses in living animals

Alexander Heisterkamp, Thanongsak Mamom, Omid Kermani, Wolfgang Drommer, Herbert Welling, Wolfgang Ertmer, Holger Lubatschowski

Proceedings Volume 4611, (2002) https://doi.org/10.1117/12.470587

KEYWORDS: Surgery, Eye, Cornea, Ultrafast phenomena, Pulsed laser operation, Laser therapeutics, Laser cutting, Tissues, Laser vision correction, Thermal effects

Read Abstract +

Proceedings Article | 1 April 2002 Paper

Ultrafast laser pulses for medical applications

Holger Lubatschowski, Alexander Heisterkamp, Fabian Will, Jesper Serbin, Thorsten Bauer, Carsten Fallnich, Herbert Welling, Wiebke Mueller, Burkard Schwab, Ajoy Singh, Wolfgang Ertmer

Proceedings Volume 4633, (2002) https://doi.org/10.1117/12.461386

KEYWORDS: Pulsed laser operation, Tissues, Laser tissue interaction, Laser ablation, Laser dentistry, Femtosecond phenomena, Cornea, Surgery, Laser cutting, Laser therapeutics

Read Abstract +

Proceedings Article | 26 October 2001 Paper

Nonlinear effects inside corneal tissue after fs-photodisruption

Alexander Heisterkamp, Tammo Ripken, Holger Lubatschowski, Herbert Welling, Wolfgang Drommer, Elke Luetkefels, Thanongsak Mamom, Wolfgang Ertmer

Proceedings Volume 4433, (2001) https://doi.org/10.1117/12.446501

KEYWORDS: Cornea, Pulsed laser operation, Laser therapeutics, Surgery, Eye, Tissues, Laser cutting, Laser vision correction, Sensors, Optical filters

Read Abstract +

Proceedings Article | 7 June 2001 Paper

Optimization of the parameters for intrastromal refractive surgery with ultrashort laser pulses

Alexander Heisterkamp, Tammo Ripken, Holger Lubatschowski, Herbert Welling, Wolfgang Dommer, Elke Luetkefels, Thanongsak Mamom, Wolfgang Ertmer

Proceedings Volume 4245, (2001) https://doi.org/10.1117/12.429279

KEYWORDS: Laser vision correction, Cornea, Surgery, Pulsed laser operation, Laser cutting, Eye, Laser therapeutics, Tissue optics, Ultrafast phenomena, Laser tissue interaction

Read Abstract +

Proceedings Article | 16 November 2000 Paper

Intrastromal cutting effects in rabbit cornea using femtosecond laser pulses

Alexander Heisterkamp, Tammo Ripken, Holger Lubatschowski, Herbert Welling, Elke Luetkefels, Wolfgang Drommer, Wolfgang Ertmer

Proceedings Volume 4161, (2000) https://doi.org/10.1117/12.409337

KEYWORDS: Cavitation, Tissue optics, Laser cutting, Cornea, Pulsed laser operation, Tissues, Eye, Femtosecond phenomena, Photography, Laser optics

Read Abstract +

Proceedings Article | 7 June 2000 Paper

Intrastromal refractive surgery by ultrashort laser pulses: side effects and mechanisms

Alexander Heisterkamp, Gero Maatz, Tammo Ripken, Holger Lubatschowski, Herbert Welling, Elke Luetkefels, Wolfgang Drommer, Wolfgang Ertmer

Proceedings Volume 3908, (2000) https://doi.org/10.1117/12.387518

KEYWORDS: Laser therapeutics, Cavitation, Cornea, Pulsed laser operation, Hydrogen, Surgery, Laser vision correction, Picosecond phenomena, Ultrafast phenomena, Scanning electron microscopy

Read Abstract +

Showing 5 of 75 publications

Proceedings Volume Editor (12)

SPIE Conference Volume | 21 March 2017

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XVII

SPIE Conference Volume | 6 June 2016

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XVI

SPIE Conference Volume | 21 April 2015

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XV

SPIE Conference Volume | 28 March 2014

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XIV

SPIE Conference Volume | 4 April 2013

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XIII

Showing 5 of 12 publications

Conference Committee Involvement (21)

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXV

25 January 2025 | San Francisco, California, United States

Lasers and Photonics for Advanced Manufacturing

8 April 2024 | Strasbourg, France

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXIV

28 January 2024 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXIII

29 January 2023 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXII

23 January 2022 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXI

6 March 2021 | Online Only, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XX

1 February 2020 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XIX

2 February 2019 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XVIII

28 January 2018 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XVII

29 January 2017 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XVI

14 February 2016 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XV

8 February 2015 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XIV

2 February 2014 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XIII

3 February 2013 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XII

22 January 2012 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XI

23 January 2011 | San Francisco, California, United States

Frontiers in Ultrafast Optics: Biomedical, Scientific and Industrial Applications X (Formerly: Commercial and Biomedical Applications of Ultrafast Lasers)

24 January 2010 | San Francisco, California, United States

Commercial and Biomedical Applications of Ultrafast Lasers IX

25 January 2009 | San Jose, California, United States

Commercial and Biomedical Applications of Ultrafast Lasers VIII

20 January 2008 | San Jose, California, United States

Commercial and Biomedical Applications of Ultrafast Lasers VII

21 January 2007 | San Jose, California, United States

Commercial and Biomedical Applications of Ultrafast Lasers VI

22 January 2006 | San Jose, California, United States

Showing 5 of 21 Conference Committees

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years