2017

Matthias Eibl, Sebastian Karpf, Hubertus Hakert, Daniel Weng, and Robert Huber,
Two-photon-excited fluorescence (TPEF) and fluorescence lifetime imaging (FLIM) with sub-nanosecond pulses and a high analog bandwidth signal detection, in Multiphoton Microscopy in the Biomedical Sciences XVII , Ammasi Periasamy and Peter T. C. So and Karsten König and Xiaoliang S. Xie, Eds. SPIE, 022017. pp. 100691F.
DOI:10.1117/12.2250831
Bibtex: BibTeX
@inproceedings{10.1117/12.2250831,
author = {Matthias Eibl and Sebastian Karpf and Hubertus Hakert and Daniel Weng and Robert Huber},
title = {{Two-photon-excited fluorescence (TPEF) and fluorescence lifetime imaging (FLIM) with sub-nanosecond pulses and a high analog bandwidth signal detection}},
volume = {10069},
booktitle = {Multiphoton Microscopy in the Biomedical Sciences XVII},
editor = {Ammasi Periasamy and Peter T. C. So and Karsten K{\"o}nig and Xiaoliang S. Xie},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {100691F},
abstract = {Two-photon excited fluorescence (TPEF) microscopy and fluorescence lifetime imaging (FLIM) are powerful imaging techniques in bio-molecular science. The need for elaborate light sources for TPEF and speed limitations for FLIM, however, hinder an even wider application. We present a way to overcome this limitations by combining a robust and inexpensive fiber laser for nonlinear excitation with a fast analog digitization method for rapid FLIM imaging. The applied sub nanosecond pulsed laser source is synchronized to a high analog bandwidth signal detection for single shot TPEF- and single shot FLIM imaging. The actively modulated pulses at 1064nm from the fiber laser are adjustable from 50ps to 5ns with kW of peak power. At a typically applied pulse lengths and repetition rates, the duty cycle is comparable to typically used femtosecond pulses and thus the peak power is also comparable at same cw-power. Hence, both types of excitation should yield the same number of fluorescence photons per time on average when used for TPEF imaging. However, in the 100ps configuration, a thousand times more fluorescence photons are generated per pulse. In this paper, we now show that the higher number of fluorescence photons per pulse combined with a high analog bandwidth detection makes it possible to not only use a single pulse per pixel for TPEF imaging but also to resolve the exponential time decay for FLIM. To evaluate the performance of our system, we acquired FLIM images of a Convallaria sample with pixel rates of 1 MHz where the lifetime information is directly measured with a fast real time digitizer. With the presented results, we show that longer pulses in the many-10ps to nanosecond regime can be readily applied for TPEF imaging and enable new imaging modalities like single pulse FLIM.},
keywords = {FLIM, TPEF, fiber laser, endoscope, MOPA, Nonlinear microscopy, Fluorescence microscopy, Lifetime-based sensing},
year = {2017},
doi = {10.1117/12.2250831},
URL = {https://doi.org/10.1117/12.2250831}
}
Tianshi Wang, Tom Pfeiffer, Min Wu, Wolfgang Wieser, Wolfgang Draxinger, Antonius F. W. van der Steen, Robert Huber, and Gijs van Soest,
Short pulse laser induced thermo-elastic deformation imaging, in Optical Interactions with Tissue and Cells XXVIII , E. Duco Jansen and Hope Thomas Beier, Eds. SPIE, 022017. pp. 100620C.
DOI:10.1117/12.2251502
Bibtex: BibTeX
@inproceedings{10.1117/12.2251502,
author = {Tianshi Wang and Tom Pfeiffer and Min Wu and Wolfgang Wieser and Wolfgang Draxinger and Antonius F. W. van der Steen and Robert Huber and Gijs van Soest},
title = {{Short pulse laser induced thermo-elastic deformation imaging}},
volume = {10062},
booktitle = {Optical Interactions with Tissue and Cells XXVIII},
editor = {E. Duco Jansen and Hope Thomas Beier},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {100620C},
abstract = {Absorption of nanosecond laser pulses induces rapid thermo-elastic deformation in tissue, i.e. a sub-micrometer scale displacement happens within a couple of microseconds. In this study, we initially investigate the depth-resolved deformation using a 1.5 MHz phase-sensitive optical coherence tomography (OCT) system. Functional images can be reconstructed based on the detected deformation, which enables a new imaging modality called thermo-elastic deformation imaging (TDI). Our results show that the associated displacement is related to the optical absorption of the short laser pulses. The TDI images can provide tissue type information in addition to the conventional OCT images.},
keywords = {thermal-elastic deformation, optical coherence tomography},
year = {2017},
doi = {10.1117/12.2251502},
URL = {https://doi.org/10.1117/12.2251502}
}
R Bliedtner, and Amelink A,
Real Time Speckle Monitoring to Control Retinal Photocoagulation, in Proc. SPIE , 2017. pp. 1041308-1-7.
Datei: 12.2287815
Bibtex: BibTeX
@inproceedings{Bliedtner2017,
   author = {Bliedtner, K; Seifert, E; Brinkmann, R and  Amelink A},
   title = {Real Time Speckle Monitoring to Control Retinal Photocoagulation},
   booktitle = {Proc. SPIE},
   
   pages = {1041308-1-7},
  
url = { https://doi.org/10.1117/12.2287815},
Year = { 2017}
}
Tom Pfeiffer, Wolfgang Draxinger, Wolfgang Wieser, Thomas Klein, Markus Petermann, and Robert Huber,
Analysis of FDML lasers with meter range coherence, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXI , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, 2017. pp. 100531T.
DOI:10.1117/12.2254792
Bibtex: BibTeX
@inproceedings{10.1117/12.2254792,
author = {Tom Pfeiffer and Wolfgang Draxinger and Wolfgang Wieser and Thomas Klein and Markus Petermann and Robert Huber},
title = {{Analysis of FDML lasers with meter range coherence}},
volume = {10053},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXI},
editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {100531T},
abstract = {FDML lasers provide sweep rates in the MHz range at wide optical bandwidths, making them ideal sources for high
speed OCT. Recently, at lower speed, ultralong-range swept-source OCT has been demonstrated using a tunable
vertical cavity surface emitting laser (VCSEL) and also using a Vernier-tunable laser. These sources provide relatively
high sweep rates and meter range coherence lengths. In order to achieve similar coherence, we developed an extremely
well dispersion compensated Fourier Domain Mode Locked (FDML) laser, running at 3.2 MHz sweep rate and 120 nm
spectral bandwidth. We demonstrate that this laser offers meter range coherence and enables volumetric long range OCT
of moving objects.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode locking, FDML, MHz OCT},
year = {2017},
doi = {10.1117/12.2254792},
URL = {https://doi.org/10.1117/12.2254792}
}

2016

Sijia Wang, Gereon Hüttmann, Tayyaba Hasan, and Ramtin Rahmanzadeh,
Molecular targeted PDT with selective delivery of ICG Photo-Immunoconjugates(Conference Presentation), in Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXV , David H. Kessel and Tayyaba Hasan, Eds. SPIE, 042016. pp. 96940O.
DOI:10.1117/12.2217572
Datei: 12.2217572
Bibtex: BibTeX
@inproceedings{10.1117/12.2217572,
author = {Sijia Wang and Gereon H{\"u}ttmann and Tayyaba Hasan and Ramtin Rahmanzadeh},
title = {{Molecular targeted PDT with selective delivery of ICG Photo-Immunoconjugates
(Conference Presentation)}},
volume = {9694},
booktitle = {Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXV},
editor = {David H. Kessel and Tayyaba Hasan},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {96940O},
keywords = {photodynamic therapy, liposome, endosomal entrapment, nanotechnology, cell proliferation, photochemical internalization},
year = {2016},
doi = {10.1117/12.2217572},
URL = {https://doi.org/10.1117/12.2217572}
}
Mario Pieper, Hinnerk Schulz-Hildebrandt, Gereon Hüttmann, and Peter König,
Imaging of mucus clearance in the airways of living spontaneously breathing mice by optical coherence microscopy (Conference Presentation), 2016. pp. 969116-969116-1.
Datei: 12.2209054
Bibtex: BibTeX
@inproceedings{Pieper2016,
   author = {Pieper, Mario and Schulz-Hildebrandt, Hinnerk and Hüttmann, Gereon and König, Peter},
   title = {Imaging of mucus clearance in the airways of living spontaneously breathing mice by optical coherence microscopy (Conference Presentation)},
   volume = {9691},
   pages = {969116-969116-1},
year = { 2016},
   note = {10.1117/12.2209054},
   abstract = {Mucus transport is essential to remove inhaled particles and pathogens from the lung. Impaired removal of mucus often results in worsening of lung diseases. To understand the mechanisms of mucus transport and to monitor the impact of therapeutic strategies, it is essential to visualize airways and mucus in living animals without disturbing transport processes by intubation or surgically opening the airways. We developed a custom-built optical coherence microscope (OCM) providing a lateral and axial resolution of approximately 1.5 µm with a field of view of 2 mm at up to 150 images/s. Images of the intact trachea and its mucus transport were recorded in anesthetized spontaneously breathing mice. NaCl solution (0.9% and 7%) or Lipopolysaccharide were applied intranasally. OCM resolved detailed structure of the trachea and enabled measuring the airway surface liquid (ASL) thickness through the tracheal wall. Without stimulation, the amount of ASL was only a few µm above the epithelium and remained constant. After intranasal application of 30 µl saline at different concentrations, an early fast cough-like fluid removal with velocities higher than 1 mm/s was observed that removed a high amount of liquid. The ASL thickness increased transiently and quickly returned to levels before stimulation. In contrast to saline, application of Lipopolysaccharide induced substantial mucus release and an additional slow mucus transport by ciliary beating (around 100 µm/s) towards the larynx was observed. In conclusion, OCM is appropriate unique tool to study mechanisms of mucus transport in the airways and effects of therapeutic interventions in living animals.},
   url = {http://dx.doi.org/10.1117/12.2209054},
   type = {Conference Proceedings}
}
Hendrik Spahr, Dierck Hillmann, Carola Hain, Clara Pfäffle, Helge Sudkamp, Gesa Franke, and Gereon Hüttmann,
Imaging vascular dynamics in human retina using full-field swept-source optical coherence tomography (Conference Presentation), 2016. pp. 96970E-96970E-1.
DOI:10.1117/12.2214303
Datei: 12.2214303
Bibtex: BibTeX
@inproceedings{Spahr2016,
   author = {Spahr, Hendrik and Hillmann, Dierck and Hain, Carola and Pfäffle, Clara and Sudkamp, Helge and Franke, Gesa and Hüttmann, Gereon},
   title = {Imaging vascular dynamics in human retina using full-field swept-source optical coherence tomography (Conference Presentation)},
   volume = {9697},
   pages = {96970E-96970E-1},
   note = {10.1117/12.2214303},
   abstract = {We demonstrate a new non-invasive method to assess the functional condition of the retinal vascular system. Phase-sensitive full-field swept-source optical coherence tomography (PhS-FF-SS-OCT) is used to investigate retinal vascular dynamics at unprecedented temporal resolution. Motion of retinal tissue, that is induced by expansion of the vessels therein, is measured with an accuracy of about 10 nm. The pulse shape of arterial and venous pulsation, their temporal delay as well as the frequency dependent pulse propagation through the capillary bed are determined. For the first time, imaging speed and motion sensitivity are sufficient for a direct measurement of pulse waves propagating with more than 600 mm/s in retinal vessels of a healthy young subject.},
   url = {http://dx.doi.org/10.1117/12.2214303},
   type = {Conference Proceedings},
year = { 2016}
}
Jan Philip Kolb, Thomas Klein, Matthias Eibl, Tom Pfeiffer, Wolfgang Wieser, and Robert Huber,
Megahertz FDML laser with up to 143nm sweep range for ultrahigh resolution OCT at 1050nm, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX , Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin, Eds. SPIE, 2016. pp. 969703.
DOI:10.1117/12.2214758
Bibtex: BibTeX
@inproceedings{10.1117/12.2214758,
author = {Jan Philip Kolb and Thomas Klein and Matthias Eibl and Tom Pfeiffer and Wolfgang Wieser and Robert Huber},
title = {{Megahertz FDML laser with up to 143nm sweep range for ultrahigh resolution OCT at 1050nm}},
volume = {9697},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX},
editor = {Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {969703},
abstract = {We present a new design of a Fourier Domain Mode Locked laser (FDML laser), which provides a new record in sweep
range at ~1μm center wavelength: At the fundamental sweep rate of 2x417 kHz we reach 143nm bandwidth and 120nm
with 4x buffering at 1.67MHz sweep rate. The latter configuration of our system is characterized: The FWHM of the
point spread function (PSF) of a mirror is 5.6μm (in tissue). Human in vivo retinal imaging is performed with the MHz
laser showing more details in vascular structures. Here we could measure an axial resolution of 6.0μm by determining
the FWHM of specular reflex in the image. Additionally, challenges related to such a high sweep bandwidth such as
water absorption are investigated.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode locking, FDML, MHz OCT},
year = {2016},
doi = {10.1117/12.2214758},
URL = {https://doi.org/10.1117/12.2214758}
}
H P Urbach,
Surface harmonics on liquid lenses, in 2016 IEEE Photonics Conference (IPC) , 2016. pp. 248-249.
DOI:10.1109/IPCon.2016.7831063
Bibtex: BibTeX
@INPROCEEDINGS{Strauch2017,
author={Strauch, M and Urbach, H P},
booktitle={2016 IEEE Photonics Conference (IPC)},
title={Surface harmonics on liquid lenses},
year={2016},

pages={248-249},
keywords={lenses;optical harmonic generation;optical tuning;oscillations;surface harmonics;liquid lenses;tunability;nonspherical surfaces;surface oscillations;Lenses;Liquids;Surface waves;Optical surface waves;Harmonic analysis;Shape;Optical switches},
doi={10.1109/IPCon.2016.7831063},
ISSN={},
month={Oct},}
Katharina Bliedtner, Eric Seifert, Leoni Stockmann, Lisa Effe, and Ralf Brinkmann,
Towards real time speckle controlled retinal photocoagulation, 2016. pp. 96931A-96931A-6.
Datei: 12.2212703
Bibtex: BibTeX
@inproceedings{Bliedtner2016,
   author = {Bliedtner, Katharina and Seifert, Eric and Stockmann, Leoni and Effe, Lisa and Brinkmann, Ralf},
   title = {Towards real time speckle controlled retinal photocoagulation},
   volume = {9693},
   pages = {96931A-96931A-6},
   note = {10.1117/12.2212703},
   abstract = {Photocoagulation is a laser treatment widely used for the therapy of several retinal diseases. Intra- and inter-individual variations of the ocular transmission, light scattering and the retinal absorption makes it impossible to achieve a uniform effective exposure and hence a uniform damage throughout the therapy. A real-time monitoring and control of the induced damage is highly requested. Here, an approach to realize a real time optical feedback using dynamic speckle analysis is presented. A 532 nm continuous wave Nd:YAG laser is used for coagulation. During coagulation, speckle dynamics are monitored by a coherent object illumination using a 633nm HeNe laser and analyzed by a CMOS camera with a frame rate up to 1 kHz. It is obvious that a control system needs to determine whether the desired damage is achieved to shut down the system in a fraction of the exposure time. Here we use a fast and simple adaption of the generalized difference algorithm to analyze the speckle movements. This algorithm runs on a FPGA and is able to calculate a feedback value which is correlated to the thermal and coagulation induced tissue motion and thus the achieved damage. For different spot sizes (50-200 μm) and different exposure times (50-500 ms) the algorithm shows the ability to discriminate between different categories of retinal pigment epithelial damage ex-vivo in enucleated porcine eyes. Furthermore in-vivo experiments in rabbits show the ability of the system to determine tissue changes in living tissue during coagulation.},
   url = {http://dx.doi.org/10.1117/12.2212703},
   type = {Conference Proceedings},
year = { 2016}
}

2015

Jan Philip Kolb, Thomas Klein, Wolfgang Wieser, Wolfgang Draxinger, and Robert Huber,
High definition in vivo retinal volumetric video rate OCT at 0.6 Giga-voxels per second, in Optical Coherence Imaging Techniques and Imaging in Scattering Media , Brett E. Bouma and Maciej Wojtkowski, Eds. SPIE, 072015. pp. 95410Z.
DOI:10.1117/12.2183768
Bibtex: BibTeX
@inproceedings{10.1117/12.2183768,
author = {Jan Philip Kolb and Thomas Klein and Wolfgang Wieser and Wolfgang Draxinger and Robert Huber},
title = {{High definition in vivo retinal volumetric video rate OCT at 0.6 Giga-voxels per second}},
volume = {9541},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media},
editor = {Brett E. Bouma and Maciej Wojtkowski},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {95410Z},
abstract = {We present full volumetric high speed OCT imaging of the retina with multiple settings varying in volume size and volume rate. The volume size ranges from 255x255 A-scans to 160x40 A-scans with 450 samples per depth scan with volume rates varying between 20.8 V/s for the largest volumes to 195.2 V/s for the smallest. The system is based on a 1060nm Fourier domain mode locked (FDML) laser with 1.6MHz line rate. Scanning along the fast axis is performed with a 2.7 kHz or 4.3 kHz resonant scanner operated in bidirectional scanning mode, while a standard galvo scanner is used for the slow axis. The performance is analyzed with respect to various potential applications, like intraoperative OCT.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode locking, FDML, MHz-OCT},
year = {2015},
doi = {10.1117/12.2183768},
URL = {https://doi.org/10.1117/12.2183768}
}
Sebastian Karpf, Matthias Eibl, and Robert Huber,
Nanosecond two-photon excitation fluorescence imaging with a multi color fiber MOPA laser, in Advanced Microscopy Techniques IV; and Neurophotonics II , Emmanuel Beaurepaire and Peter T. C. So and Francesco Pavone and Elizabeth M. Hillman, Eds. SPIE, 072015. pp. 953616.
DOI:10.1117/12.2183854
Bibtex: BibTeX
@inproceedings{10.1117/12.2183854,
author = {Sebastian Karpf and Matthias Eibl and Robert Huber},
title = {{Nanosecond two-photon excitation fluorescence imaging with a multi color fiber MOPA laser}},
volume = {9536},
booktitle = {Advanced Microscopy Techniques IV; and Neurophotonics II},
editor = {Emmanuel Beaurepaire and Peter T. C. So and Francesco Pavone and Elizabeth M. Hillman},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {953616},
abstract = {A system is presented that uses a fiber based Master Oscillator Power Amplifier (MOPA) with nanosecond-range pulses for two-photon excitation fluorescence (TPEF) imaging. The robust laser in the extended near infrared is based on an actively modulated electro-optical modulator (EOM), enabling free synchronization of the pulses to any other light source or detection unit. Pulses with a freely programmable duration between 0.4 and 10 ns are generated and then amplified to up to kilowatts of peak power with ytterbium doped fiber amplifiers (YDFA). Since we achieve peak power and duty cycles comparable to standard femto- and picosecond setups, the TPEF signal levels are similar, but realized with a robust and inexpensive fiber-based setup. The delivery fiber is further used as an optional, electronically controllable Raman shifter to effectively shift the 1064 nm light to 1122 nm and to 1186 nm. This allows imaging of a manifold of fluorophores, like e.g. TexasRed, mCherry, mRaspberry and many more. We show TPEF imaging of the autofluorescence of plant leaves of moss and algae, acquired in epi-direction. This modular laser unit can be integrated into existing systems as either a fiber-based, alignment free excitation laser or an extension for multi-modal imaging.},
keywords = {multi-photon imaging, TPEF, MOPA, TPA, fiber laser, Raman shifter, non-linear imaging, multi-modal imaging},
year = {2015},
doi = {10.1117/12.2183854},
URL = {https://doi.org/10.1117/12.2183854}
}
Matthias Eibl, Sebastian Karpf, Wolfgang Wieser, Thomas Klein, and Robert Huber,
Hyperspectral stimulated Raman microscopy with two fiber laser sources, in Advanced Microscopy Techniques IV; and Neurophotonics II , SPIE, 072015. pp. 953604.
DOI:10.1117/12.2183822
Bibtex: BibTeX
@inproceedings{10.1117/12.2183822,
author = {Matthias Eibl and Sebastian Karpf and Wolfgang Wieser and Thomas Klein and Robert Huber},
title = {{Hyperspectral stimulated Raman microscopy with two fiber laser sources}},
volume = {9536},
booktitle = {Advanced Microscopy Techniques IV; and Neurophotonics II},
editor = {Emmanuel Beaurepaire and Peter T. C. So and Francesco Pavone and Elizabeth M. Hillman},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {953604},
abstract = {A fast all fiber based setup for stimulated Raman microscopy based on a rapidly wavelength swept cw-laser is presented. The applied Fourier domain mode locked (FDML) laser is a fiber ring laser, providing a continuously changing wavelength output over time. This fast swept source allows us to rapidly change the wavelength and, thereby the energy difference with respect to a single color pump laser. The pump laser is a master oscillator power amplifier based on a fiber amplified laser diode and a Raman shifter. By controlled variation of the relative timing between probe and pump laser with an arbitrary waveform generator, the Raman signals are encoded in time and they are directly acquired with a synchronized, fast analog-to-digital converter. This setup is capable of acquiring rapidly high resolution spectra (up to 0.5 cm<sup>-1</sup>) with shot noise limited sensitivity over a broadband (750 cm<sup>-1</sup> to 3150 cm<sup>-1</sup>) spectral region. Here, we show the performance of this system for imaging in the CH-stretch region around 3000 cm<sup>-1</sup> and in the fingerprint region around 1600 cm<sup>-1</sup>. We present hyperspectral images of a plant stem slice with molecular contrast of lignin and a lipid representative as well as images of PS (polystyrene) and PMMA (poly(methyl methacrylate) beads with an acquisition speed of 18 &mu;s per spectral point.},
keywords = {stimulated Raman, multiphoton, microscopy, coherent Raman, fiber laser, FDML, TICO, hyperspectral},
year = {2015},
doi = {10.1117/12.2183822},
URL = {https://doi.org/10.1117/12.2183822}
}
Wolfgang Wieser, Thomas Klein, Wolfgang Draxinger, and Robert Huber,
Fully automated 1.5 MHz FDML laser with more than 100mW output power at 1310 nm, in Optical Coherence Imaging Techniques and Imaging in Scattering Media , Brett E. Bouma and Maciej Wojtkowski, Eds. SPIE, 072015. pp. 954116.
DOI:10.1117/12.2183431
Bibtex: BibTeX
@inproceedings{10.1117/12.2183431,
author = {Wolfgang Wieser and Thomas Klein and Wolfgang Draxinger and Robert Huber},
title = {{Fully automated 1.5 MHz FDML laser with more than 100mW output power at 1310 nm}},
volume = {9541},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media},
editor = {Brett E. Bouma and Maciej Wojtkowski},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {954116},
abstract = {While FDML lasers with MHz sweep speeds have been presented five years ago, these devices have required manual control for startup and operation. Here, we present a fully self-starting and continuously regulated FDML laser with a sweep rate of 1.5 MHz. The laser operates over a sweep range of 115 nm centered at 1315 nm, and provides very high average output power of more than 100 mW. We characterize the laser performance, roll-off, coherence length and investigate the wavelength and phase stability of the laser output under changing environmental conditions. The high output power allows optical coherence tomography (OCT) imaging with an OCT sensitivity of 108 dB at 1.5 MHz.},
keywords = {OCT, optical coherence tomography, swept laser, wavelength-swept laser, fiber laser, MHz-OCT, Fourier-domain mode-locking, FDML},
year = {2015},
doi = {10.1117/12.2183431},
URL = {https://doi.org/10.1117/12.2183431}
}
Sebastian Karpf, Matthias Eibl, Wolfgang Wieser, Thomas Klein, and Robert Huber,
Time-encoded Raman scattering (TICO-Raman) with Fourier domain mode locked (FDML) lasers, in Optical Coherence Imaging Techniques and Imaging in Scattering Media , Brett E. Bouma and Maciej Wojtkowski, Eds. SPIE, 072015. pp. 95410F.
DOI:10.1117/12.2183859
Bibtex: BibTeX
@inproceedings{10.1117/12.2183859,
author = {Sebastian Karpf and Matthias Eibl and Wolfgang Wieser and Thomas Klein and Robert Huber},
title = {{Time-encoded Raman scattering (TICO-Raman) with Fourier domain mode locked (FDML) lasers}},
volume = {9541},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media},
editor = {Brett E. Bouma and Maciej Wojtkowski},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {95410F},
abstract = {We present a new concept for performing stimulated Raman spectroscopy and microscopy by employing rapidly wavelength swept Fourier Domain Mode locked (FDML) lasers [1]. FDML lasers are known for fastest imaging in swept-source optical coherence tomography [2, 3]. We employ this continuous and repetitive wavelength sweep to generate broadband, high resolution stimulated Raman spectra with a new, time-encoded (TICO) concept [4]. This allows for encoding and detecting the stimulated Raman gain on the FDML laser intensity directly in time. Therefore we use actively modulated pump lasers, which are electronically synchronized to the FDML laser, in combination with a fast analog-to-digital converter (ADC) at 1.8 GSamples/s. We present hyperspectral Raman images with color-coded, molecular contrast.},
keywords = {swept lasers, FDML, TICO-Raman, fiber lasers, stimulated Raman microscopy, Raman spectroscopy, molecular contrast, multi-modal imaging},
year = {2015},
doi = {10.1117/12.2183859},
URL = {https://doi.org/10.1117/12.2183859}
}
Tom Pfeiffer, Wolfgang Wieser, Thomas Klein, Markus Petermann, Jan Philip Kolb, Matthias Eibl, and Robert Huber,
Flexible A-scan rate MHz OCT: computational downscaling by coherent averaging, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX , Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin, Eds. SPIE, 042015. pp. 96970S-96970S-5.
DOI:10.1117/12.2214788
Bibtex: BibTeX
@inproceedings{10.1117/12.2214788,
author = {Tom Pfeiffer and Wolfgang Wieser and Thomas Klein and Markus Petermann and Jan-Phillip Kolb and Matthias Eibl and Robert Huber},
title = {{Flexible A-scan rate MHz OCT: computational downscaling by coherent averaging}},
volume = {9697},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XX},
editor = {Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {96970S},
abstract = {In order to realize fast OCT-systems with adjustable line rate, we investigate averaging of image data from an FDML based
MHz-OCT-system. The line rate can be reduced in software and traded in for increased system sensitivity and image
quality. We compare coherent and incoherent averaging to effectively scale down the system speed of a 3.2 MHz FDML
OCT system to around 100 kHz in postprocessing. We demonstrate that coherent averaging is possible with MHz systems
without special interferometer designs or digital phase stabilisation. We show OCT images of a human finger knuckle joint
in vivo with very high quality and deep penetration.},
keywords = {Optical coherence tomography, OCT, Fourier domain mode locking, FDML, MHz OCT, averaging, tunable laser},
year = {2016},
doi = {10.1117/12.2214788},
URL = {https://doi.org/10.1117/12.2214788}
}
Jan Philip Kolb, Philipp Schwarz, Thomas Klein, Wolfgang Wieser, and Robert Huber,
Dual parametric compounding approach for speckle reduction in OCT, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, 032015. pp. 93123G.
DOI:10.1117/12.2077659
Bibtex: BibTeX
@inproceedings{10.1117/12.2077659,
author = {Jan Philip Kolb and Philipp Schwarz and Thomas Klein and Wolfgang Wieser and Robert Huber},
title = {{Dual parametric compounding approach for speckle reduction in OCT}},
volume = {9312},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX},
editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {93123G},
abstract = {OCT as a coherent imaging technique inherently suffers from speckle. We present a new dual parametric compounding approach to reduce speckle. The approach is to acquire several OCT volumes with different numerical apertures (NAs). Then in post processing, a first spatial compounding step is performed by averaging of adjacent B-frames. In a second step data from the different volume is averaged. Retinal imaging data comparing this idea with standard spatial compounding is presented and analyzed and necessary parameters such as the required variation of the NA and number of different NAs are discussed},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode lockng, FDML, MHz OCT},
year = {2015},
doi = {10.1117/12.2077659},
URL = {https://doi.org/10.1117/12.2077659}
}
Jan Philip Kolb, Thomas Klein, Wolfgang Wieser, Wolfgang Draxinger, and Robert Huber,
Full volumetric video rate OCT of the posterior eye with up to 195.2 volumes/s, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, 032015. pp. 931202.
DOI:10.1117/12.2077147
Bibtex: BibTeX
@inproceedings{10.1117/12.2077147,
author = {Jan Philip Kolb and Thomas Klein and Wolfgang Wieser and Wolfgang Draxinger and Robert Huber},
title = {{Full volumetric video rate OCT of the posterior eye with up to 195.2 volumes/s}},
volume = {9312},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX},
editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {931202},
abstract = {Full volumetric high speed OCT imaging of the retina with multiple settings varying in volume size and volume rate is
presented. The volume size ranges from 255x255 A-scans to 160x40 A-scans with 450 samples per depth scan. The
volume rates vary between 20.8 V/s for the largest volumes to 195.2 V/s for the smallest. The system is based on a
1060nm Fourier domain mode locked (FDML) laser with 1.6MHz line rate. Scanning along the fast axis is performed
with a 2.7 kHz or 4.3 kHz resonant scanner operated in bidirectional scanning mode, while a standard galvo scanner is
used for the slow axis. The performance is analyzed with respect to various potential applications, like intraoperative
OCT.},
keywords = {Optical coherence tomography, OCT, tunable laser, Fourier domain mode lockng, FDML, MHz OCT},
year = {2015},
doi = {10.1117/12.2077147},
URL = {https://doi.org/10.1117/12.2077147}
}
W Schwarzer, S Koinzer, and K Schlott,
Power-controlled temperature guided retinal photocoagulation , in Photonic West BIOS , 2015.
Datei: 12.2083042
Bibtex: BibTeX
@inproceedings{Baade2015,
   author = {Baade, A and Schwarzer, W and Koinzer, S and Schlott, K and Birngruber, R and Brinkman, R},
   title = {Power-controlled temperature guided retinal photocoagulation },
   booktitle = {Photonic West BIOS},
   type = {Conference Proceedings},
url = { https://doi.org/10.1117/12.2083042},
year = { 2015}
}

2014

J Horstmann,
Speckle-based holographic detection for non-contact Photoacoustic Tomography, in 48th annual conference of the German Society for Biomedical Engineering , 08.. 2014. pp. 844-847.
Bibtex: BibTeX
@inproceedings{Buj14,
   author = {Buj, C and Horstmann, J and Münter, M and Brinkmann, R},
   title = {Speckle-based holographic detection for non-contact Photoacoustic Tomography},
   booktitle = {48th annual conference of the German Society for Biomedical Engineering},
   volume = {59},
   pages = {844-847},
   type = {Conference Proceedings},
Year = { 2014}
}

Matthias Eibl, Sebastian Karpf, Wolfgang Wieser, Thomas Klein, and Robert Huber,
Broadband, High Resolution Stimulated Raman Spectroscopy with Rapidly Wavelength Swept cw-Lasers, in CLEO: 2014 , Optica Publishing Group, 2014. pp. ATu3P.4.
DOI:10.1364/CLEO_AT.2014.ATu3P.4
Bibtex: BibTeX
@inproceedings{Eibl:14,
author = {Matthias Eibl and Sebastian Karpf and Wolfgang Wieser and Thomas Klein and Robert Huber},
booktitle = {CLEO: 2014},
journal = {CLEO: 2014},
keywords = {Lasers, tunable; Scattering, stimulated Raman; Spectroscopy, Raman; Laser light; Laser sources; Master oscillator power amplifiers; Raman spectroscopy; Self phase modulation; Stimulated Raman scattering},
pages = {ATu3P.4},
publisher = {Optica Publishing Group},
title = {Broadband, High Resolution Stimulated Raman Spectroscopy with Rapidly Wavelength Swept cw-Lasers},
year = {2014},
url = {https://opg.optica.org/abstract.cfm?URI=CLEO_AT-2014-ATu3P.4},
doi = {10.1364/CLEO_AT.2014.ATu3P.4},
abstract = {A fast all fiber based setup for stimulated Raman spectroscopy with a rapidly wavelength swept cw-laser is presented. It enables flexible acquisition of broadband (750 cm{\textminus}1 to 3150 cm{\textminus}1) spectra with high resolution (0.5 cm{\textminus}1).},
}
Sebastian Karpf, Matthias Eibl, Wolfgang Wieser, Thomas Klein, and Robert Huber,
Hyperspectral Stimulated Raman Microscopy with Fiber-based, Rapidly Wavelength Swept cw-Lasers, in CLEO: 2014 , Optica Publishing Group, 2014. pp. SM3P.3.
DOI:10.1364/CLEO_SI.2014.SM3P.3
Bibtex: BibTeX
@inproceedings{Karpf:14,
author = {Sebastian Karpf and Matthias Eibl and Wolfgang Wieser and Thomas Klein and Robert Huber},
booktitle = {CLEO: 2014},
journal = {CLEO: 2014},
keywords = {Lasers, tunable; Scattering, stimulated Raman; Raman microscopy; Biological imaging; Medical imaging; Optical coherence tomography; Raman microscopy; Raman scattering; Swept lasers},
pages = {SM3P.3},
publisher = {Optica Publishing Group},
title = {Hyperspectral Stimulated Raman Microscopy with Fiber-based, Rapidly Wavelength Swept cw-Lasers},
year = {2014},
url = {https://opg.optica.org/abstract.cfm?URI=CLEO_SI-2014-SM3P.3},
doi = {10.1364/CLEO_SI.2014.SM3P.3},
abstract = {A hyperspectral stimulated Raman microscopy system using rapidly wavelength swept lasers is presented. Imaging of biological samples with shot noise limited detection is demonstrated with the fiber based setup.},
}
J Horstmann,
Optical full-field holographic detection system for non-contact photoacoustic tomography, Proc. SPIE, 2014.
Bibtex: BibTeX
@inproceedings{
   author = {Horstmann, J and Brinkmann, R},
   title = {Optical full-field holographic detection system for non-contact photoacoustic tomography},
   publisher = {Proc. SPIE},
year = {2014},
   type = {Conference Proceedings}
}

2013

B. Olzowy, N. Starke, T. Schuldt, Gereon Hüttmann, Eva Lankenau, and Tino Just,
Optical coherence tomography and confocal endomicroscopy for rhinologic pathologies: a pilot study, in Head and Neck Optical Diagnostics , Christian Betz and Brian J. F. Wong M.D., Eds. SPIE, 062013. pp. 880505.
DOI:10.1117/12.2033174
Datei: 12.2033174
Bibtex: BibTeX
@inproceedings{10.1117/12.2033174,
author = {B. Olzowy and N. Starke and T. Schuldt and G. H{\"u}ttmann and E. Lankenau and T. Just},
title = {{Optical coherence tomography and confocal endomicroscopy for rhinologic pathologies: a pilot study}},
volume = {8805},
booktitle = {Head and Neck Optical Diagnostics},
editor = {Christian Betz and Brian J. F. Wong M.D.},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {880505},
keywords = {optical coherence tomography, confocal microscopy, inverted papilloma , chronic rhinosinusitis, nasal polyps, mucociliary function, ciliated epithelium},
year = {2013},
doi = {10.1117/12.2033174},
URL = {https://doi.org/10.1117/12.2033174}
}
Tianshi Wang, Wolfgang Wieser, Geert Springeling, Robert Beurskens, Charles T. Lancee, Tom Pfeiffer, Antonius F. W. van der Steen, Robert Huber, and Gijs van Soest,
Ultrahigh-speed intravascular optical coherence tomography imaging at 3200 frames per second, in Optical Coherence Tomography and Coherence Techniques VI , Brett E. Bouma and Rainer A. Leitgeb, Eds. SPIE, 062013. pp. 88020O.
DOI:10.1117/12.2032723
Bibtex: BibTeX
@inproceedings{10.1117/12.2032723,
author = {Tianshi Wang and Wolfgang Wieser and Geert Springeling and Robert Beurskens and Charles T. Lancee and Tom Pfeiffer and Antonius F. W. van der Steen and Robert Huber and Gijs van Soest},
title = {{Ultrahigh-speed intravascular optical coherence tomography imaging at 3200 frames per second}},
volume = {8802},
booktitle = {Optical Coherence Tomography and Coherence Techniques VI},
editor = {Brett E. Bouma and Rainer A. Leitgeb},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {88020O},
abstract = {We demonstrated intravascular OCT imaging with frame rate up to 3.2 kHz (192,000 rpm scanning). This was achieved by
using a custom-built catheter in which the circumferential scanning was actuated by a 1.0 mm diameter synchronous
motor. The OCT system was based on a Fourier Domain Mode Locked laser operating at an A-line rate of 1.6 MHz. The
diameter of the catheter was 1.1 mm at the tip. Ex vivo images of human coronary artery (~78.4 mm length) were acquired
at a pullback speed of 100 mm/s. True 3D volumetric imaging of the entire artery, with adequate sampling in all
dimensions, was performed in &lt; 1 second acquisition time.},
year = {2013},
doi = {10.1117/12.2032723},
URL = {https://doi.org/10.1117/12.2032723}
}