@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}
}

@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}
}

@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}
}

@article{Huber:15,
author = {Robert Huber},
journal = {Opt. Photon. News},
keywords = {Image processing; Optical coherence tomography; Lasers, tunable; Medical optics and biotechnology; Optical coherence tomography; Image processing; Imaging techniques; Line scan cameras; Medical imaging; Optical coherence tomography; Three dimensional imaging},
number = {6},
pages = {32--39},
publisher = {Optica Publishing Group},
title = {4-D Real-Time Optical Coherence Tomography},
volume = {26},
month = {Jun},
year = {2015},
url = {https://www.optica-opn.org/abstract.cfm?URI=opn-26-6-32},
doi = {10.1364/OPN.26.6.000032},
abstract = {Advances in OCT techniques, combined with the processing power of moderncomputer hardware, are adding a new dimension---time---to a familiar 3-D imaging method.The result could be new applications in research and the biomedicalclinic.},
}

@article{Jirauschek:15,
author = {Christian Jirauschek and Robert Huber},
journal = {Opt. Lett.},
keywords = {Laser theory; Lasers, tunable; Optical coherence tomography; Birefringence; Polarization; Pulses; Cross phase modulation; Mode locking; Optical components; Picosecond pulses; Polarization mode dispersion; Pulse generation},
number = {10},
pages = {2385--2388},
publisher = {Optica Publishing Group},
title = {Modeling and analysis of polarization effects in Fourier domain mode-locked lasers},
volume = {40},
month = {May},
year = {2015},
url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-40-10-2385},
doi = {10.1364/OL.40.002385},
abstract = {We develop a theoretical model for Fourier domain mode-locked (FDML) lasers in a non-polarization-maintaining configuration, which is the most widely used type of FDML source. This theoretical approach is applied to analyze a widely wavelength-swept FDML setup, as used for picosecond pulse generation by temporal compression of the sweeps. We demonstrate that good agreement between simulation and experiment can only be obtained by including polarization effects due to fiber bending birefringence, polarization mode dispersion, and cross-phase modulation into the theoretical model. Notably, the polarization dynamics are shown to have a beneficial effect on the instantaneous linewidth, resulting in improved coherence and thus compressibility of the wavelength-swept FDML output.},
}

@Article{HU_2014_Zhang_a,
  Title                    = {{Optical coherence tomography guided laser cochleostomy: towards the accuracy on tens of micrometer scale}},
  Author                   = {Zhang, Yaokun and Pfeiffer, Tom and Weller, Marcel and Wieser, Wolfgang and Huber, Robert and Raczkowsky, J\"{o}rg and Schipper, J\"{o}rg and W\"{o}rn, Heinz and Klenzner, Thomas},
  Journal                  = {BioMed research international},
  Year                     = {2014},
  Month                    = jan,
  Pages                    = {251814--24},
  Volume                   = {2014},
  Doi                      = {10.1155/2014/251814},
  ISSN                     = {2314-6141},
keywords = {AG-Huber_OCT},
  Url                      = {http://www.hindawi.com/journals/bmri/2014/251814/}
}

@Article{HU_2014_Reznicek_a,
  Title                    = {{Megahertz ultra-wide-field swept-source retina optical coherence tomography compared to current existing imaging devices.}},
  Author                   = {Reznicek, Lukas and Klein, Thomas and Wieser, Wolfgang and Kernt, Marcus and Wolf, Armin and Haritoglou, Christos and Kampik, Anselm and Huber, Robert and Neubauer, Aljoscha S},
  Journal                  = {Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv f\"{u}r klinische und experimentelle Ophthalmologie},
  Year                     = {2014},

  Month                    = jun,
  Number                   = {6},
  Pages                    = {1009--16},
  Volume                   = {252},

  Doi                      = {10.1007/s00417-014-2640-4},
  ISSN                     = {1435-702X},
keywords = {AG-Huber_OCT},
  Url                      = {http://link.springer.com/article/10.1007\%2Fs00417-014-2640-4}
}

@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.},
}

@article{Wieser:14,
author = {Wolfgang Wieser and Wolfgang Draxinger and Thomas Klein and Sebastian Karpf and Tom Pfeiffer and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Optical coherence tomography; Lasers, tunable; Optical coherence tomography; Endoscopic imaging; Full field optical coherence tomography; Functional imaging; Image quality; Ophthalmic imaging; Vertical cavity surface emitting lasers},
number = {9},
pages = {2963--2977},
publisher = {Optica Publishing Group},
title = {High definition live 3D-OCT in vivo: design and evaluation of a 4D OCT engine with 1 GVoxel/s},
volume = {5},
month = {Sep},
year = {2014},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-5-9-2963},
doi = {10.1364/BOE.5.002963},
abstract = {We present a 1300 nm OCT system for volumetric real-time live OCT acquisition and visualization at 1 billion volume elements per second. All technological challenges and problems associated with such high scanning speed are discussed in detail as well as the solutions. In one configuration, the system acquires, processes and visualizes 26 volumes per second where each volume consists of 320 x 320 depth scans and each depth scan has 400 usable pixels. This is the fastest real-time OCT to date in terms of voxel rate. A 51 Hz volume rate is realized with half the frame number. In both configurations the speed can be sustained indefinitely. The OCT system uses a 1310 nm Fourier domain mode locked (FDML) laser operated at 3.2 MHz sweep rate. Data acquisition is performed with two dedicated digitizer cards, each running at 2.5 GS/s, hosted in a single desktop computer. Live real-time data processing and visualization are realized with custom developed software on an NVidia GTX 690 dual graphics processing unit (GPU) card. To evaluate potential future applications of such a system, we present volumetric videos captured at 26 and 51 Hz of planktonic crustaceans and skin.},
}

@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).},
}

@Article{HU_2014_Wieser_b,
  Title                    = {{A 4-D OCT Engine with 1 GVoxel/s}},
  Author                   = {Wieser, Wolfgang and Draxinger, Wolfgang and Klein, Thomas and Karpf, Sebastian and Pfeiffer, Tom and Huber, Robert},
  Journal                  = {Optics and Photonics News},
  Year                     = {2014},

  Month                    = dec,
  Number                   = {12},
  Pages                    = {36 },
  Volume                   = {25},
keywords = {AG-Huber_FDML, AG-Huber_OCT},

  Publisher                = {OSA},
  Url                      = { http://www.osa-opn.org/home/articles/volume_25/december_2014/extras/a_4-d_oct_engine_with_1_gvoxel_s/#.VcH21Pl5raw}
}

@article{Kolb2014,
   author = {Kolb, Jan Philip and Klein, Thomas and Mohler, Kathrin and Wieser, Wolfgang and Reznicek, Lukas and Kernt, Marcus and Kampik, Anselm and Neubauer, Aljoscha S. and Huber, Robert},
   title = {Widefield Megahertz (MHz) OCT of diabetic retinopathy},
   journal = {Investigative Ophthalmology & Visual Science},
   volume = {55},
   number = {13},
   pages = {5018-5018},
   abstract = { PurposeTo investigate morphological appearance of diabetic retinopathy and laser effects in panretinal laser photocoagulation with a widefield MHz OCT (60° field of view, 120° center angle).  MethodsA custom swept-source OCT device with a 1060nm Fourier-domain mode-locked laser source achieving a line rate of 1.68MHz was used to investigate 15 consecutive patients with diabetic retinopathy. Within 1.82s datasets consisting of 2088x1024 A-scans over 60° were acquired. The densely sampled three dimensional datasets were investigated in various B-Scan cross-sections as well as en-face images and 3D reconstructions. Selected findings were compared with SLO images from a widefield SLO (Optos, Dunfermeline, UK).  ResultsOn the densely sampled 3D and en-face images, hard exsudates, peripheral laser spots as well as proliferative neovascularization were readily detected. Characteristic structural changes resulting from laser burns could easily be visualized across the whole field of view in the OCT datasets. In addition, depth-scans and B-scans allowed to identify additional structural changes including IS/OS disruption, RPE detachment or neovascularisation reaching into the vitreous across the field of view.  ConclusionsThree dimensional visualization of the retina over 60° field of view with a MHz OCT is feasible in patients with diabetic retinopathy. It might allow additional clinical insights in peripheral changes such as laser spots or retinal neovascularisation. 3D reconstruction of OCT dataset of patient with diabetic retinopathy with neovascularization (green), hard exsudates (yellow), epiretinal membrane and peripheral retinal scars after panretinal laser treatment (blue). Indications with arrows are examplatory. Top: En-face of same patient as in figure 1. Red line indicates the position of B-Frame below. Retinal scars due to focal laser coagulation temporal of the fovea visible. Bottom: Neovascularisation (green) reaching into the vitreous is visible on the left side. Retinal scars especially on RPE level due to panretinal laser treatment (blue) are observable.},
   ISSN = {1552-5783},
   url = {http://dx.doi.org/},
   year = {2014},
keywords = {AG-Huber_OCT},
   type = {Journal Article}
}

@article{Klein2014,
   author = {Klein, Thomas and Draxinger, Wolfgang and Mohler, Kathrin and Kolb, Jan Philip and Wieser, Wolfgang and Kampik, Anselm and Neubauer, Aljoscha S. and Wolf, Armin and Huber, Robert},
   title = {Wide-field choroidal thickness and en-face maps of patients created with MHz-OCT},
   journal = {Investigative Ophthalmology & Visual Science},
   volume = {55},
   number = {13},
   pages = {1620-1620},
   abstract = { PurposeTo study the feasibility of simultaneous peripheral and central choroidal thickness measurement and en-face visualization in patients with a variety of diseases, using a single high-resolution wide-field MHz-OCT dataset spanning more than 50 degrees field of view.  MethodsIn this retrospective study, choroidal morphology of 29 patients imaged with MHz-OCT was assessed. MHz-OCT is a custom SS-OCT operating at 1060nm and an axial line rate of 1.68MHz. The high speed, more than 30 times faster than current commercial devices, enabled a very high resolution scan protocol of 2088x1024 A-scans over a wide field of ~60 degrees. However, due to the very high speed, signal strength is lower compared to slower devices. Hence, thickness and structure maps were only created for selected datasets: The positions of Bruch’s membrane and choroid sclera junction were determined manually by a trained observer a subset of all A-scans, from which thickness and intensity maps were created.  ResultsDespite relative low signal strength, the choroid sclera junction could be clearly observed over the entire unshadowed image area in 15 of 29 patients. Apart from shadowing, visibility of this junction shows strong variation even within a single dataset due to varying retinal thickness, eye-blinks, saccades and retinal curvature. Thus, thickness could be evaluated at least in some areas for all 29 patients, especially in the periphery. Moreover, choroidal thickness varied considerably intra- and interindividually. In two patients, abrupt changes of the choroid were observed in the temporal periphery, which may resemble morphology or imaging artifact. In addition to thickness, en-face choroidal structure maps were extracted from the segmented OCT datasets. Visibility of choroidal vasculature in these maps correlates with choroidal thickness.  ConclusionsChoroidal thickness and structure in patients could be visualized over large areas for the first time. Due to focal choroidal thickness changes with large thickness gradients, high-density scan protocols may be favorable for OCT-based investigations of the choroid. En-face images of the choroid can be extracted from these high-resolution datasets, but the influence of choroidal thickness on the image information should be taken into account. Choroidal en-face image (top), color-coded thickness map with superimposed structural image (middle) and OCT B-frame (bottom) for two eyes (A,B).},
   ISSN = {1552-5783},
   url = {http://dx.doi.org/},
   year = {2014},
keywords = {AG-Huber_OCT},
   type = {Journal Article}
}

@article{Kortuem2014,
   author = {Kortuem, Karsten Ulrich and Kolb, Jan Philip and Klein, Thomas and Mohler, Kathrin and Kampik, Anselm and Neubauer, Aljoscha S. and Wieser, Wolfgang and Huber, Robert and Haritoglou, Christos},
   title = {Wide Field MHz OCT imaging of the vitreoretinal interface},
   journal = {Investigative Ophthalmology & Visual Science},
   volume = {55},
   number = {13},
   pages = {1619-1619},
   abstract = { PurposeTo investigate changes caused by vitreoretinal interface disease with a multi-MHz OCT over a wide field of view of 60°.  MethodsWe used custom swept-source OCT device with a 1060nm Fourier-domain mode-locked laser source achieving a line rate of 1.68MHz. Within 1.82s datasets consisting of 2088x1024 A-scans over 60° were acquired from 5 patients with vitreoretinal traction due to VMTS and 3 patients with vascular pathology. The densely sampled three dimensional datasets were investigated in B-Scan cross-sections as well as en-face images and 3D reconstructions.  ResultsVitreoretinal traction could be imaged well in most of the cases, although the current sensitivity of the system limited image quality. Across the whole 60° field of view in the OCT datasets vitreoretinal tractions could be topographically assessed, always including the macula and optic disc, where vitreous anchorage could be shown. By means of the depth-scans as part of the 3D OCT volume we could image traction-associated retinal changes such as retinal elevation or RPE detachment.  ConclusionsThis unique three dimensional visualization of the retina over 60° field of view with a MHz OCT is feasible in patients with vitreoretinal interface disease and might offer additional clinical insights on the three-dimensional topology of tractional changes. Three dimensional Wide Field MHz OCT retinal and vitreous visualization.},
   ISSN = {1552-5783},
   url = {http://dx.doi.org/},
   year = {2014},
keywords = {AG-Huber_OCT},
   type = {Journal Article}
}

@Article{HU_2014_Karpf_a,
  Title                    = {{Time-Encoded Raman: Fiber-based, hyperspectral, broadband stimulated Raman microscopy}},
  Author                   = {Karpf, Sebastian and Eibl, Matthias and Wieser, Wolfgang and Klein, Thomas and Huber, Robert},
  journal = {ArXiv e-prints},
  Year                     = {2014},
  Archiveprefix            = {arXiv},
  Arxivid                  = {1405.4181},
  Eprint                   = {1405.4181},
keywords = {AG-Huber_NL},
  Url                      = {http://arxiv.org/abs/1405.4181}
}

@article{Klein:13,
author = {Thomas Klein and Wolfgang Wieser and Lukas Reznicek and Aljoscha Neubauer and Anselm Kampik and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Medical optics instrumentation; Lasers, fiber; Medical and biological imaging; Ophthalmic optics and devices ; Optical coherence tomography; Adaptive optics; Distributed Bragg reflectors; Fiber Bragg gratings; Functional imaging; Image quality; Three dimensional imaging},
number = {10},
pages = {1890--1908},
publisher = {Optica Publishing Group},
title = {Multi-MHz retinal OCT},
volume = {4},
month = {Oct},
year = {2013},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-4-10-1890},
doi = {10.1364/BOE.4.001890},
abstract = {We analyze the benefits and problems of in vivo optical coherence tomography (OCT) imaging of the human retina at A-scan rates in excess of 1 MHz, using a 1050 nm Fourier-domain mode-locked (FDML) laser. Different scanning strategies enabled by MHz OCT line rates are investigated, and a simple multi-volume data processing approach is presented. In-vivo OCT of the human ocular fundus is performed at different axial scan rates of up to 6.7 MHz. High quality non-mydriatic retinal imaging over an ultra-wide field is achieved by a combination of several key improvements compared to previous setups. For the FDML laser, long coherence lengths and 72 nm wavelength tuning range are achieved using a chirped fiber Bragg grating in a laser cavity at 419.1 kHz fundamental tuning rate. Very large data sets can be acquired with sustained data transfer from the data acquisition card to host computer memory, enabling high-quality averaging of many frames and of multiple aligned data sets. Three imaging modes are investigated: Alignment and averaging of 24 data sets at 1.68 MHz axial line rate, ultra-dense transverse sampling at 3.35 MHz line rate, and dual-beam imaging with two laser spots on the retina at an effective line rate of 6.7 MHz.},
}

@article{Klein:13,
author = {Thomas Klein and Raphael Andr\'{e} and Wolfgang Wieser and Tom Pfeiffer and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Speckle; Medical optics instrumentation; Medical and biological imaging; Optical coherence tomography; Functional imaging; High speed imaging; Image quality; Imaging techniques; Medical imaging; Ophthalmic imaging},
number = {4},
pages = {619--634},
publisher = {Optica Publishing Group},
title = {Joint aperture detection for speckle reduction and increased collection efficiency in ophthalmic MHz OCT},
volume = {4},
month = {Apr},
year = {2013},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-4-4-619},
doi = {10.1364/BOE.4.000619},
abstract = {Joint-aperture optical coherence tomography (JA-OCT) is an angle-resolved OCT method, in which illumination from an active channel is simultaneously probed by several passive channels. JA-OCT increases the collection efficiency and effective sensitivity of the OCT system without increasing the power on the sample. Additionally, JA-OCT provides angular scattering information about the sample in a single acquisition, so the OCT imaging speed is not reduced. Thus, JA-OCT is especially suitable for ultra high speed in-vivo imaging. JA-OCT is compared to other angle-resolved techniques, and the relation between joint aperture imaging, adaptive optics, coherent and incoherent compounding is discussed. We present angle-resolved imaging of the human retina at an axial scan rate of 1.68 MHz, and demonstrate the benefits of JA-OCT: Speckle reduction, signal increase and suppression of specular and parasitic reflections. Moreover, in the future JA-OCT may allow for the reconstruction of the full Doppler vector and tissue discrimination by analysis of the angular scattering dependence.},
}

@article{Wang:13,
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},
journal = {Opt. Lett.},
keywords = {Optical coherence tomography; Endoscopic imaging; Endoscopic imaging; Fourier domain mode locking; Image quality; Laser modes; Optical coherence tomography; Three dimensional imaging},
number = {10},
pages = {1715--1717},
publisher = {Optica Publishing Group},
title = {Intravascular optical coherence tomography imaging at 3200 frames per second},
volume = {38},
month = {May},
year = {2013},
url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-38-10-1715},
doi = {10.1364/OL.38.001715},
abstract = {We demonstrate intravascular optical coherence tomography (OCT) imaging with frame rate up to 3.2\&\#xA0;kHz (192,000\&\#xA0;rpm scanning). This was achieved by using a custom-built catheter in which the circumferential scanning was actuated by a 1.0\&\#xA0;mm diameter synchronous motor. The OCT system, with an imaging depth of 3.7\&\#xA0;mm (in air), is based on a Fourier domain mode locked laser operating at an A-line rate of 1.6\&\#xA0;MHz. The diameter of the catheter is 1.1\&\#xA0;mm at the tip. Ex vivo images of human coronary artery (78.4\&\#xA0;mm length) were acquired at a pullback speed of 100\&\#x2009;\&\#x2009;mm/s. True 3D volumetric imaging of the entire artery, with dense and isotropic sampling in all dimensions, was performed in \<1 second acquisition time.},
}

@inproceedings{10.1117/12.2006979,
author = {Yaokun Zhang and Tom Pfeiffer and Wolfgang Wieser and Marcel Weller and Robert Huber and Thomas Klenzner and J{\"o}rg Raczkowsky and Heinz W{\"o}rn},
title = {{History compounding: a novel speckle reduction technique for OCT guided cochleostomy}},
volume = {8571},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XVII},
editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {85713H},
abstract = {Optical coherence tomography (OCT) is a promising candidate for monitoring the bottom of the drilled channel during
cochleostomy to prevent injury to the critical structure under the bone tissue. While the thickness of the overlaying bone
tissue is changed during the drilling process, the wave front of the backscattered light is also altered, resulting in
changing speckle patterns of the observed structures in the sequential historical scans. By averaging the different patterns
in these scans, named history compounding, the speckles can be reduced and the detection of critical structure becomes
much easier. Before averaging, the refractive index of bone tissue ???????? has to be compensated so that the speckles of the
same structure in different historical scans can be aligned together. An accurate method for measuring the refractive
index n<sub>b</sub> using OCT is presented. Experiments were conducted to evaluate history compounding and the new technique
is proved to be an effective, flexible and intuitive speckle reduction technique for OCT guided cochleostomy as well as
hard tissue ablation of other kind.},
keywords = {optical coherence tomography, speckle reduction, refractive index, cochleostomy, hard tissue ablation},
year = {2013},
doi = {10.1117/12.2006979},
URL = {https://doi.org/10.1117/12.2006979}
}

@INPROCEEDINGS{6801995,
  author={Karpf, Sebastian and Eibl, Matthias and Wieser, Wolfgang and Klein, Thomas and Huber, Robert},
  booktitle={2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC}, 
  title={FDML Raman: New high resolution SRS with ultra broadband spectral coverage}, 
  year={2013},
  volume={},
  number={},
  pages={1-1},
  doi={10.1109/CLEOE-IQEC.2013.6801995}}

@inproceedings{Karpf:13,
author = {Sebastian Karpf and Matthias Eibl and Wolfgang Wieser and Thomas Klein and Robert Huber},
booktitle = {CLEO: 2013},
journal = {CLEO: 2013},
keywords = {Lasers, fiber; Scattering, stimulated Raman; Spectroscopy, Raman; Fourier domain mode locking; Lasers; Optical coherence tomography; Raman lasers; Raman spectroscopy; Swept lasers},
pages = {CTu2H.5},
publisher = {Optica Publishing Group},
title = {FDML Raman: High Speed, High Resolution Stimulated Raman Spectroscopy with Rapidly Wavelength Swept Lasers},
year = {2013},
url = {https://opg.optica.org/abstract.cfm?URI=CLEO_SI-2013-CTu2H.5},
doi = {10.1364/CLEO_SI.2013.CTu2H.5},
abstract = {An all fiber based system for high speed, high resolution Raman sensing is presented. The system is based on a wavelength swept Fourier Domain Mode Locked (FDML) laser for the detection of the Raman signal.},
}

@article{10.1371/journal.pone.0081499,
    doi = {10.1371/journal.pone.0081499},
    author = {Choi, WooJhon AND Mohler, Kathrin J. AND Potsaid, Benjamin AND Lu, Chen D. AND Liu, Jonathan J. AND Jayaraman, Vijaysekhar AND Cable, Alex E. AND Duker, Jay S. AND Huber, Robert AND Fujimoto, James G.},
    journal = {PLOS ONE},
    publisher = {Public Library of Science},
    title = {Choriocapillaris and Choroidal Microvasculature Imaging with Ultrahigh Speed OCT Angiography},
    year = {2013},
    month = {12},
    volume = {8},
    url = {https://doi.org/10.1371/journal.pone.0081499},
    pages = {1-8},
    abstract = {We demonstrate in vivo choriocapillaris and choroidal microvasculature imaging in normal human subjects using optical coherence tomography (OCT). An ultrahigh speed swept source OCT prototype at 1060 nm wavelengths with a 400 kHz A-scan rate is developed for three-dimensional ultrahigh speed imaging of the posterior eye. OCT angiography is used to image three-dimensional vascular structure without the need for exogenous fluorophores by detecting erythrocyte motion contrast between OCT intensity cross-sectional images acquired rapidly and repeatedly from the same location on the retina. En face OCT angiograms of the choriocapillaris and choroidal vasculature are visualized by acquiring cross-sectional OCT angiograms volumetrically via raster scanning and segmenting the three-dimensional angiographic data at multiple depths below the retinal pigment epithelium (RPE). Fine microvasculature of the choriocapillaris, as well as tightly packed networks of feeding arterioles and draining venules, can be visualized at different en face depths. Panoramic ultra-wide field stitched OCT angiograms of the choriocapillaris spanning ∼32 mm on the retina show distinct vascular structures at different fundus locations. Isolated smaller fields at the central fovea and ∼6 mm nasal to the fovea at the depths of the choriocapillaris and Sattler's layer show vasculature structures consistent with established architectural morphology from histological and electron micrograph corrosion casting studies. Choriocapillaris imaging was performed in eight healthy volunteers with OCT angiograms successfully acquired from all subjects. These results demonstrate the feasibility of ultrahigh speed OCT for in vivo dye-free choriocapillaris and choroidal vasculature imaging, in addition to conventional structural imaging.},
    number = {12},

}

@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 < 1 second acquisition time.},
year = {2013},
doi = {10.1117/12.2032723},
URL = {https://doi.org/10.1117/12.2032723}
}

@article{10.1117/1.JBO.18.2.026008,
author = {Teresa Torzicky and Sebastian Marschall and Michael Pircher and Bernhard Baumann and Marco Bonesi and Stefan Zotter and Erich G{\"o}tzinger and Wolfgang Trasischker and Thomas Klein and Wolfgang Wieser and Benjamin R. Biedermann and Robert A. Huber and Peter E. Andersen and Christoph K. Hitzenberger},
title = {{Retinal polarization-sensitive optical coherence tomography at 1060 nm with 350 kHz A-scan rate using an Fourier domain mode locked laser}},
volume = {18},
journal = {Journal of Biomedical Optics},
number = {2},
publisher = {SPIE},
pages = {026008},
abstract = {We present a novel, high-speed, polarization-sensitive, optical coherence tomography set-up for retinal imaging operating at a central wavelength of 1060 nm which was tested for in vivo imaging in healthy human volunteers. We use the system in combination with a Fourier domain mode locked laser with active spectral shaping which enables the use of forward and backward sweep in order to double the imaging speed without a buffering stage. With this approach and with a custom designed data acquisition system, we show polarization-sensitive imaging with an A-scan rate of 350 kHz. The acquired three-dimensional data sets of healthy human volunteers show different polarization characteristics in the eye, such as depolarization in the retinal pigment epithelium and birefringence in retinal nerve fiber layer and sclera. The increased speed allows imaging of large volumes with reduced motion artifacts. Moreover, averaging several two-dimensional frames allows the generation of high-definition B-scans without the use of an eye-tracking system. The increased penetration depth of the system, which is caused by the longer probing beam wavelength, is beneficial for imaging choroidal and scleral structures and allows automated segmentation of these layers based on their polarization characteristics.},
keywords = {Optical coherence tomography, Polarization, Birefringence, Imaging systems, Data acquisition, Image segmentation, Modulation, Mode locking, 3D acquisition, Retinal scanning},
year = {2013},
doi = {10.1117/1.JBO.18.2.026008},
URL = {https://doi.org/10.1117/1.JBO.18.2.026008}
}

@Article{HU_2013_Eigenwillig_b,
  Title                    = {{Picosecond pulses from wavelength-swept continuous-wave Fourier domain mode-locked lasers}},
  Author                   = {Eigenwillig, Christoph M and Wieser, Wolfgang and Todor, Sebastian and Biedermann, Benjamin R and Klein, Thomas and Jirauschek, Christian and Huber, Robert},
  Journal                  = {Nature communications},
  Year                     = {2013},
  Month                    = jan,
  Pages                    = {1848--1855},
  Volume                   = {4},
  Doi                      = {10.1038/ncomms2870},
  ISSN                     = {2041-1723},
keywords = {AG-Huber_FDML, AG-Huber_OCT},
  Url                      = {http://www.nature.com/ncomms/journal/v4/n5/abs/ncomms2870.html}
}

@INPROCEEDINGS{6801076,
  author={Eigenwillig, Christoph M. and Todor, Sebastian and Wieser, Wolfgang and Biedermann, Benjamin R. and Klein, Thomas and Jirauschek, Christian and Huber, Robert},
  booktitle={2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC}, 
  title={Picosecond pulses from a Fourier domain mode locked (FDML) laser}, 
  year={2013},
  volume={},
  number={},
  pages={1-1},
  doi={10.1109/CLEOE-IQEC.2013.6801076}}

@inproceedings{10.1117/12.908798,
author = {Thomas Klein and Wolfgang Wieser and Raphael Andr{\'e} and Tom Pfeiffer and Christoph M. Eigenwillig and Robert Huber},
title = {{Multi-MHz FDML OCT: snapshot retinal imaging at 6.7 million axial-scans per second}},
volume = {8213},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XVI},
editor = {Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {82131E},
abstract = {We demonstrate the acquisition of densely sampled wide-field 3D OCT datasets of the human retina in 0.3s. This
performance is achieved with a multi-MHz Fourier domain mode-locked (FDML) laser source operating at 1050nm. A two-beam
setup doubles the 3.35MHz laser sweep rate to 6.7MHz, which is 16x faster than results achieved with any non-FDML
source used for retinal OCT. We discuss two main benefits of these high line rates: First, large datasets over an ultra-wide
field of view can be acquired with a low probability of distortions. Second, even if eye movements occur, now the scan rate
is high enough to directly correct even the fastest saccades without loss of information.},
keywords = {Optical coherence tomography, OCT, MHz OCT, Fourier-domain mode-locking, FDML, retinal imaging},
year = {2012},
doi = {10.1117/12.908798},
URL = {https://doi.org/10.1117/12.908798}
}

@article{Blatter:12,
author = {Cedric Blatter and Branislav Grajciar and Pu Zou and Wolfgang Wieser and Aart-Jan Verhoef and Robert Huber and Rainer A. Leitgeb},
journal = {Opt. Lett.},
keywords = {Optical coherence tomography; Optical coherence tomography; Photoacoustic imaging; Interferometric imaging ; Photoacoustics ; In vivo imaging; Interferometry; Linewidth; Medical imaging; Optical coherence tomography; Swept sources},
number = {21},
pages = {4368--4370},
publisher = {Optica Publishing Group},
title = {Intrasweep phase-sensitive optical coherence tomography for noncontact optical photoacoustic imaging},
volume = {37},
month = {Nov},
year = {2012},
url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-37-21-4368},
doi = {10.1364/OL.37.004368},
abstract = {We introduce a method to extract the photoacoustic (PA) signal from the phase time evolution of an optical coherence tomography (OCT) swept source spectral sweep. This all-optical detection is achieved in a noncontact fashion directly on the sample surface by using its specular reflection. High-speed measurement and referencing allow for close to shot noise limited phase-sensitive detection. It offers a simple way to perform OCT and PA imaging by sharing the same system components.},
}

@article{Blatter:12,
author = {Cedric Blatter and Jessika Weingast and Aneesh Alex and Branislav Grajciar and Wolfgang Wieser and Wolfgang Drexler and Robert Huber and Rainer A. Leitgeb},
journal = {Biomed. Opt. Express},
keywords = {Optical coherence tomography; Optical coherence tomography; Flow diagnostics; Functional monitoring and imaging ; Fourier domain mode locking; High speed imaging; Image processing; In vivo imaging; Speckle imaging; Three dimensional imaging},
number = {10},
pages = {2636--2646},
publisher = {Optica Publishing Group},
title = {In situ structural and microangiographic assessment of human skin lesions with high-speed OCT},
volume = {3},
month = {Oct},
year = {2012},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-3-10-2636},
doi = {10.1364/BOE.3.002636},
abstract = {We demonstrate noninvasive structural and microvascular contrast imaging of different human skin diseases in vivo using an intensity difference analysis of OCT tomograms. The high-speed swept source OCT system operates at 1310 nm with 220 kHz A-scan rate. It provides an extended focus by employing a Bessel beam. The studied lesions were two cases of dermatitis and two cases of basal cell carcinoma. The lesions show characteristic vascular patterns that are significantly different from healthy skin. In case of inflammation, vessels are dilated and perfusion is increased. In case of basal cell carcinoma, the angiogram shows a denser network of unorganized vessels with large vessels close to the skin surface. Those results indicate that assessing vascular changes yields complementary information with important insight into the metabolic demand.},
}

@inproceedings{10.1117/12.922313,
author = {Sebastian Marschall and Teresa Torzicky and Thomas Klein and Wolfgang Wieser and Michael Pircher and Erich G{\"o}tzinger and Stefan Zotter and Marco Bonesi and Benjamin Biedermann and Christian Pedersen and Robert Huber and Christoph Hitzenberger and Peter Andersen},
title = {{High-speed polarization-sensitive OCT at 1060 nm using a Fourier domain mode-locked swept source}},
volume = {8427},
booktitle = {Biophotonics: Photonic Solutions for Better Health Care III},
editor = {J{\"u}rgen Popp and Wolfgang Drexler and Valery V. Tuchin and Dennis L. Matthews},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {84271D},
abstract = {Optical coherence tomography (OCT) in the 1060nm range is interesting for in vivo imaging of the human
posterior eye segment (retina, choroid, sclera), as it permits a long penetration depth. Complementary to
structural images, polarization-sensitive OCT (PS-OCT) images visualize birefringent, polarization-maintaining
or depolarizing areas within the sample. This information can be used to distinguish retinal layers and structures
with different polarization properties. High imaging speed is crucial for imaging ocular structures in vivo in order
to minimize motion artifacts while acquiring sufficiently large datasets. Here, we demonstrate PS-OCT imaging
at 350 kHz A-scan rate using a two-channel PS-OCT system in conjunction with a Fourier domain mode-locked
laser. The light source spectrum spans up to 100nm around the water absorption minimum at 1060 nm. By
modulating the laser pump current, we can optimize the spectrum and achieve a depth resolution of 9 μm in air
(6.5 μm in tissue). We acquired retinal images in vivo with high resolution and deep penetration into choroid and
sclera, and features like the depolarizing RPE or an increasing phase retardation at the chorio-scleral interface
are clearly visualized.},
keywords = {optical coherence tomography, polarization-sensitive OCT, swept source, Fourier domain mode-locking, 1060 nm},
year = {2012},
doi = {10.1117/12.922313},
URL = {https://doi.org/10.1117/12.922313}
}