A5042345483- Optical Imaging and Spectroscopy Techniques
- Photoacoustic and Ultrasonic Imaging
- Random lasers and scattering media
- Optical Coherence Tomography Applications
- Laser Material Processing Techniques
- Non-Invasive Vital Sign Monitoring
- Thermoregulation and physiological responses
- Ocular and Laser Science Research
- Laser Applications in Dentistry and Medicine
- Mass Spectrometry Techniques and Applications
- Orbital Angular Momentum in Optics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Neural dynamics and brain function
- Solid State Laser Technologies
- Optical Polarization and Ellipsometry
- Semiconductor materials and interfaces
- Photorefractive and Nonlinear Optics
- Mechanical and Optical Resonators
- Advanced Fiber Laser Technologies
- Electron and X-Ray Spectroscopy Techniques
- Laser Design and Applications
- Laser-Matter Interactions and Applications
- Dental Anxiety and Anesthesia Techniques
- Spectroscopy and Laser Applications
- Diamond and Carbon-based Materials Research
Friedrich-Alexander-Universität Erlangen-Nürnberg
2019-2024
Advanced Optical Technologies (United States)
2018-2023
Max Planck Institute for Biophysical Chemistry
1992-1994
The ablation of lithium niobate (LiNbO3), poly(tetrafluoroethylene) (PTFE, teflon), poly(methylmethacrylate) (PMMA) and polyimide (PI) by 500 fs UV excimer laser pulses at 248 nm is reported. Time-resolved measurements were carried out with pulse pairs variable delay in the range from −200 to +200 ps. rate very sensitive time between two pulses, —depending on material fluence—can increase or decrease for short delays. For LiNbO3, efficient shielding observed within a few picoseconds. PTFE...
Abstract In recent years, the laser has become an important tool in hospitals. Laser surgery particular many advantages. However, there is still a lack of understanding influence relevant parameters for surgery. order to fill this gap, pulse frequency, use exhaustion system, air cooling, power, scan speed, line energy and waiting time between cuts were analysed by ANOVA using inter-animal variation as benchmark. The quality was quantized previously published scoring system. A total 1710...
Laser surgery provides clean, fast and accurate cutting of tissue. However, it is difficult to detect what kind tissue being cut. Therefore, a wrong cut may lead iatrogenic damage structures. A feedback system should automatically stop the process when nerve reached or accidentally prevent its damage. This could increase applicability safety using laser scalpel in surgical procedures. In this study, random lasing (RL) used differentiate between skin, fat, muscle Among these types, special...
The determination of the optical properties a turbid medium is major topic in field optics. Generally, they comprise parameters µa , µs g and n. There is, however, lack techniques for direct scattering coefficient . This study, therefore, proposes random laser (RL) as tool to directly measure - not μs' Evidence found that it possible determine diffusive regime by means RL. Based on these findings, local model RL developed presented this study.
In general, the measurement of main three optical properties ( µ a , s and g ) in turbid media requires very precise total transmission (TT), reflection (TR) collimated (CT). Furthermore, an inverse algorithm such as adding doubling or Monte-Carlo-simulations is required for reconstruction properties. Despite many available methods, error free scattering coefficient g-factor still remains challenging. this study, we present way to directly calculate from transmission. To allow this, it can...
In this study, it is shown that the dynamics of lasing threshold and intensity saturation a diffusive random laser can be visualized by one spectral feature: peak wavelength shift (tunability). The varied ink concentration pump energy were utilized to experimentally induce dynamics. It was found progressively turns from blueshift redshift upon crossing threshold. A unique regime instead point revealed. This also compared with those deduced replica symmetry breaking Lévy statistics, both are...
Multiple diseases are associated with a wide spectrum of microvascular dysfunctions, microangiopathies and microcirculation disorders. Monitoring the could thus be useful to diagnose many local systemic circulatory disorders supervise critically ill patients. Many scores currently available help identify condition disorder invasive or leave scope for interpretation. Thus, present study aims investigate Monte-Carlo simulations (as numerical solutions radiative transfer equation) whether...
Abstract The laser has become an integral part of modern medicine, procedures based on this technique have found their way into a multitude medical disciplines. There is, however, no data available the detailed quantitative development use in sector. This fact gave rise to idea present study, which analyzed raw quality report German hospitals with respect subject. Over 9 years report, steady increase cumulative number cases was evident, although not all body regions is used followed trend....
Abstract Due to significant advantages, the trend in field of medical technology is moving towards minimally or even non-invasive examination methods. In this respect, optical methods offer inherent benefits, as does diffuse reflectance imaging (DRI). The present study attempts prove suitability DRI—when implemented alongside a suitable setup and data evaluation algorithm—to derive information from anatomically correctly scaled human capillaries (diameter: $$10\,\upmu \hbox {m}$$ <mml:math...
The need for tissue contact makes photoacoustic imaging not applicable special medical applications like wound imaging, endoscopy, or laser surgery. An easy, stable, and contact-free sensing technique might thus help to broaden the of modality. In this work, it is demonstrated first time that remote by speckle analysis can be performed in MHz sampling range tracking a single using four quadrant photo-detector. A speckle, which created self-interference surface back-reflection, temporally...
In medical applications, hyper-spectral imaging is becoming more and common. It has been shown to be effective for classification segmentation than normal RGB because narrower wavelength bands are used, providing a higher contrast. However, until now, the fact that images also contain information about three-dimensional structure of turbid media neglected. this study, it possible derive depth inclusions in phantoms from single image. Here, encoded by combination scattering absorption within...
For many applications in tissue optics, knowledge of the scattering coefficient or at least reduced is essential. In addition, its spectral dependence also an important feature, as this provides information about scatterer sizes. While characterization should be a simple fit, experimental results show strong fluctuations even for same type. in-vivo measurements, problem greater. Therefore, it aim study to analyze instabilities characterizations and find solution by means Bayesian inference....
Various clinically applicable scores and indices are available to help identify the state of a microcirculatory disorder in patient. Several these methods, however, leave room for interpretation only provide clues diagnosis. Thus, measurement method that allows reliable detection impending or manifest circulatory malfunctions would be great value. In this context, optical non-invasive shifted position-diffuse reflectance imaging (SP-DRI) was developed. It determine capillary diameter thus...
Chronic kidney disease (CKD) is a global burden affecting both children and adults. Novel imaging modalities hold great promise to visualize quantify structural, functional, molecular organ damage. The aim of the study was murine renal vasculature using label-free raster scanning optoacoustic mesoscopy (RSOM) in explanted organs from mice with injury.For experiments, freshly bisected kidneys alpha 8 integrin knock-out (KO) wildtype (WT) were used. A total n=7 female (n=4 KO, n=3 WT) n=6 male...
Brillouin scattering is a nonlinear effect in optical fibers which can be used for temperature or strain sensing. For read-out and analysis of the scattered signal, spectrum-analyzers with very high resolution complex detection systems are currently needed. In this work, new modality radial acoustic modes based on speckle-sensing presented.
Abstract The idea of laser surgery is nearly as old the itself. From first trials to modern systems, it was and aim selectively cut tissue in focus spot without causing harm surrounding structures. This only possible when correct parameters for surgical are chosen. Usually, this done by parameter studies. However, concrete evaluation scheme often differs between groups more precise approaches require staining microscopic evaluation. To overcome these issues, a macroscopic scoring system...
A random laser-assisted whispering gallery mode laser is presented. It provides an approach to accurately determine the microscale structure even in scattering environments. The resonator size results derived from wavelength spectrum, Fourier transformed and camera image are agreement.
Lasers have become a generally accepted tool for surgery due to their advantages compared traditional approaches like the scalpel. However, lasers lack feedback system safe laser guidance. This problem prevents potential application lot of medical cases in clinical environment. In this work, new tissue differentiation modality which might be implemented as using remote speckle-sensing is presented. tested on three types and results are discussed.