Match!
Johannes Roths
Munich University of Applied Sciences
55Publications
4H-index
86Citations
Publications 55
Newest
#1Gabriele Marchi (Munich University of Applied Sciences)H-Index: 3
#2Peter Foehr (TUM: Technische Universität München)H-Index: 5
Last.Johannes Roths (Munich University of Applied Sciences)H-Index: 4
view all 6 authors...
Abstract Objective In this study we aim to show that an optical fiber Bragg grating-based microindentation system, which has the potential to be deployed arthroscopically, can differentiate between healthy and degenerated articular cartilage, which represents an important challenge in minimally-invasive surgery. Design Twenty bovine osteochondral cylinders, extracted from the patellar groove of ten 24 months old animals were subjected to stepwise in vitro stress-relaxation indentation measuremen...
#1Gaopeng Wang (WUT: Wuhan University of Technology)H-Index: 7
#2Yuhuan Qin (WUT: Wuhan University of Technology)H-Index: 3
Last.Minghong Yang (WUT: Wuhan University of Technology)H-Index: 16
view all 8 authors...
Abstract A novel fiber Bragg grating (FBG) hydrogen sensor based on WO 3 -Pd 2 Pt-Pt composite film and controllable laser heating system is proposed and experimentally demonstrated with improved performance. The hydrogen sensor is a small stainless steel tube with two gas holes. The stainless steel tube contains two single mode fibers. One is inscribed with two short-period FBGs for monitoring the hydrogen concentration and ambient temperature, and the other is linked with 980 nm laser for opti...
#1Florian Heilmeier (TUM: Technische Universität München)H-Index: 1
#2Robert Koos (TUM: Technische Universität München)H-Index: 1
Last.Wolfram Volk (TUM: Technische Universität München)H-Index: 12
view all 8 authors...
Fibre Bragg Gratings (FBGs) were employed as internal strain sensors within tensile specimens that were machined out of a casted aluminium alloy. Embedded FBGs have the potential to directly measure strains within a casted part for a better understanding of load cases for the part design process. In addition, if the FBGs remain in the part, strains can be measured under real-life conditions and return valuable evidence for health monitoring. The proof of application is provided by the presented ...
#1Gabriele Marchi (Munich University of Applied Sciences)H-Index: 3
#2Peter Foehr (TUM: Technische Universität München)H-Index: 5
Last.Rainer Burgkart (TUM: Technische Universität München)H-Index: 28
view all 10 authors...
In this study, the capability of a fiber optic microindenter sensor to discriminate between healthy and slightly degenerated human articular cartilage samples is demonstrated. The purely optical indenter sensor is characterized by extremely reduced dimensions (0.125 mm in diameter and 27 mm in length) in comparison to existing indenter probes offering advantages for endoscopic deployment. The indenter sensor is intended to assist the surgeon in the identification of damaged articular cartilage. ...
#1Barbara HopfH-Index: 3
#2Bennet FischerH-Index: 1
Last.Johannes RothsH-Index: 4
view all 5 authors...
A novel technique for strain and temperature decoupling with surface-glued fiber Bragg gratings (FBGs) is presented and applied for strain-independent temperature measurements in a temperature range between −30 °C and 110 °C with uncertainties below 4 °C over the entire measurement range. The influence of temperature-dependent glue-induced transversal forces on the fiber sensor could be eliminated with a sensor element consisting of two FBGs in identical polarization-maintaining fibers that were...
#1Binod Bastola (Institut national de la recherche scientifique)H-Index: 1
#2B. Fischer (Institut national de la recherche scientifique)
Last.Andreas Ruediger (Institut national de la recherche scientifique)H-Index: 9
view all 4 authors...
Abstract Despite the relevance of glass fibers and integrated optical circuits for an increasing number of cutting-edge applications ranging from telecommunication to sensing and quantum photonics, the knowledge about their structural and chemical properties is still in its infancy. Optical spectroscopy techniques are challenged due to the intrinsically low cross-sections for inelastic processes. Our approach is to detect these properties along the core, extending the interaction to the fiber le...
#1Markus Lindner (Munich University of Applied Sciences)H-Index: 2
#2Edis Tunc (Munich University of Applied Sciences)H-Index: 1
Last.Johannes Roths (Munich University of Applied Sciences)H-Index: 4
view all 8 authors...
An array of regenerated fiber Bragg gratings (RFBGs) was employed to monitor the temperature distribution during an aluminum cast process. Significant temperature gradients in the cast part were observed during the cooling and solidification period. The direction and velocity of the solidification front was revealed by the temperature data obtained by the RFBGs at different measurement points. A generalized calibration curve was established and applied to the RFBG array, avoiding the need of ind...
#1Franz J. Dutz (Munich University of Applied Sciences)H-Index: 1
#2Valentin Stephan (Munich University of Applied Sciences)H-Index: 1
Last.Heinz P. Huber (Munich University of Applied Sciences)H-Index: 19
view all 6 authors...
Here, we describe a method for producing locally micro-structured fiber Bragg gratings (LMFGB) by fs-laser machining. This technique enables the precise and reproducible ablation of cladding material to create circumferential grooves inside the claddings of optical fibers. From initial ablation experiments we acquired optimized process parameters. The fabricated grooves were located in the middle of uniform type I fiber Bragg gratings. LMFBGs with four different groove widths of 48, 85, 135 and ...
123456