@inproceedings{10.1117/12.3045055,
author = {Marie Klufts and Wolfgang Draxinger and Simon Lotz and Robert Huber},
title = {{1.7MHz, 840nm swept-source ophthalmic OCT}},
volume = {13300},
booktitle = {Ophthalmic Technologies XXXV},
editor = {Daniel X. Hammer and Derek Nankivil and Yuankai K. Tao},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1330004},
keywords = {swept source, SS-OCT, FDML , Retinal imaging, ophthalmic imaging, OCT, 850 nm, short wavelength},
year = {2025},
doi = {10.1117/12.3045055},
URL = {https://doi.org/10.1117/12.3045055}
}

@inproceedings{10.1117/12.3046222,
author = {Sazgar Burhan and Berenice Schulte and Madita G{\"o}b and Awanish Pratap Singh and Bayan Mustafa and Simon Lotz and Wolfgang Draxinger and Philipp Lamminger and Yasmeine Saker and Tim Eixmann and Martin Ahrens and Marvin Heimke and Tillmann Heinze and Thilo Wedel and Maik Rahlves and Mark Ellrichmann and Robert Huber},
title = {{Switchable lateral resolution real-time MHz-OCT rectoscopy for enhanced colorectal disease diagnosis}},
volume = {13305},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXIX},
editor = {Rainer A. Leitgeb and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1330512},
abstract = {Endoscopic optical coherence tomography (OCT) offers in vivo live visualization of transmural structures with histological resolution, making it a valuable tool in medical imaging. In gastroenterology, OCT endoscopy is particularly advantageous for assessing rectal wall layers, providing superior axial and lateral resolution compared to conventional rectal endoscopic ultrasound. However, the large diameter and uneven colon surface present challenges for comprehensive imaging. Extending the OCT imaging range addresses this issue by enabling a thorough examination of the entire colon, facilitating the detection of surface polyps, tumors, and their infiltration depth. Once these regions of interest are identified, high-resolution imaging becomes essential for detailed evaluation. To meet these demands, this study integrates two different imaging modes, an extended-range mode, and a high-detail mode, within a rigid rectoscope. The extended-range mode enables visualization of deeper structures, while the high-detail mode enhances image quality for precise, contact-based assessments. The system allows seamless, real-time transitions between the modes using a 3.2MHz-OCT system and a fiber‑optic MEMS switch.},
keywords = {Optical Coherence Tomography, Megahertz OCT, Fourier Domain Mode Locking, Three-dimensional image acquisition, Rectal Imaging, Long-Range Imaging, Non-Invasive Diagnostic Imaging, Tumor Assessment},
year = {2025},
doi = {10.1117/12.3046222},
URL = {https://doi.org/10.1117/12.3046222}
}

@inproceedings{10.1117/12.3046386,
author = {M. A. Bashir and M. Klufts and S. Lotz and R. Huber},
title = {{Towards ultrahigh resolution MHz retinal SS-OCT: 187nm section-wise tuning of a FDML laser at 1050nm}},
volume = {13305},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXIX},
editor = {Rainer A. Leitgeb and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {133050K},
,
keywords = {wavelength-swept laser, FDML lasers, Optical coherence tomography, Fourier domain mode locked lasers, Broadband lasers, tunable lasers, swept lasers, swept source OCT},
year = {2025},
doi = {10.1117/12.3046386},
URL = {https://doi.org/10.1117/12.3046386}
}

@inproceedings{10.1117/12.3046216,
author = {Sazgar Burhan and Madita G{\"o}b and Mario Pieper and Tjalfe Laedtke and Thorge Grahl and Michael M{\"u}nter and Hinnerk Schulz-Hildebrandt and Gereon H{\"u}ttmann and Peter K{\"o}nig and Robert Huber},
title = {{Large-area dynamic contrast MHz optical coherence tomography for label-free imaging of porcine tissue}},
volume = {13305},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXIX},
editor = {Rainer A. Leitgeb and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1330502},
abstract = {We demonstrate a 3.2 MHz-OCT system for inter-volumetric dynamic optical coherence tomography of ex vivo porcine kidney tissue. Employing a home-built Fourier Domain mode locking (FDML) laser with a 1310 nm wavelength, the system achieved a lateral resolution of 3.48 μm and a frame rate of 612 Hz. A motorized XYZ positioning stage enabled the precise acquisition of multiple volumes, which were seamlessly stitched together to generate a comprehensive dataset with a total area of 2.6 × 2.6 mm<sup>2</sup>. Validations against histological sections confirmed the system’s ability to visualize cellular tissue structures.},
keywords = {Optical Coherence Tomography, Megahertz OCT, Fourier Domain Mode Locking, Dynamic OCT, Functional OCT, Three-dimensional image acquisition, Tissue Dynamics, Kidney},
year = {2025},
doi = {10.1117/12.3046216},
URL = {https://doi.org/10.1117/12.3046216}
}

@inproceedings{10.1117/12.3047226,
author = {Paul Strenge and Birgit Lange and Wolfgang Draxinger and Dirk Theisen-Kunde and Sonja Spahr-Hess and Matteo M. Bonsanto and Robert Huber and Ralf Brinkmann and Heinz Handels},
title = {{Enhancing brain tumor detection using optical coherence tomography and variational autoencoders}},
volume = {13410},
booktitle = {Medical Imaging 2025: Clinical and Biomedical Imaging},
editor = {Barjor S. Gimi and Andrzej Krol},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {134101P},
abstract = {Neurosurgical intervention is critical in brain tumor treatment, with long-term survival closely linked to the extent of tumor resection. The goal is to completely remove tumor tissue while preserving healthy tissue, a challenging task due to the diffuse nature of some brain tumors, such as glioblastoma, which infiltrate healthy tissue in ways that are difficult to distinguish histologically. Current intraoperative imaging techniques, including MRI and fluorescence microscopy, are limited in reliably identifying tumor tissue. Optical coherence tomography (OCT) offers a promising alternative, providing non-invasive, high-resolution cross-sectional images. This study investigates the use of a variational autoencoder (VAE) in combination with an evidential learning framework to enhance the classification of brain tissues in OCT images. The classification approach, applied to ex vivo OCT images captured at a wavelength of 1300 nm, achieved an average precision of 0.87 and a recall of 0.88 for the discrimination of healthy and tumorous brain tissue with consideration of prediction uncertainties. This method demonstrated improved discrimination between healthy white matter and tumor-infiltrated white matter compared to previous studies.},
keywords = {brain tumor, OCT, variational autoencoders, glioblastoma, classification, medical imaging, brain, evidential learning},
year = {2025},
doi = {10.1117/12.3047226},
URL = {https://doi.org/10.1117/12.3047226}
}

@inproceedings{10.1117/12.3041264,
author = {Kimberley L{\"u}hring and Birgit Lange and Lion Sch{\"u}tzeck and Ralf Brinkmann},
title = {{Laser lithotripsy: the impact of beam profile and wavelength on stone ablation}},
volume = {13293},
booktitle = {Advanced Photonics in Urology 2025},
editor = {Hyun Wook Kang and Ronald Sroka and Jian J. Zhang},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1329306},
abstract = {Thulium fiber lasers (TFL) with a peak power of 500W were introduced a few years ago for clinical use in laser lithotripsy of urinary stones. To compare the TFL with the current gold standard, the Ho:YAG laser, single pulse experiments were performed at 1.5J from different working distances using a 365μm fiber. For evaluation of the fragmentation properties of both laser systems, cuttlefish bone samples and glued BegoStone cylinders were ablated at 1.5J using different pulse durations. It was found that the TFL produced up to two times higher stone ablation compared to the Ho:YAG laser but showed significantly poorer results in fragmentation which might be explained by its lower peak power. Furthermore, the increase in the ablation efficiency of laser lithotripsy by adjusting the beam profile was investigated in this study. A series of measurements with annular and circular beam profiles of the same beam diameter was performed with the TFL. At a pulse energy of 1J the annular beam profile has removed 90% more stone volume with a single pulse.},
keywords = {laser lithotropsy, thulium fiber laser, beam profile, urolithiasis},
year = {2025},
doi = {10.1117/12.3041264},
URL = {https://doi.org/10.1117/12.3041264}
}

@inproceedings{10.1117/12.3000908,
author = {Alexander Altmann and Christian Schell and Ramtin Rahmanzadeh},
title = {{Assessing food degradation and microbial growth by sensor read-out with fluorescence spectroscopy}},
volume = {12861},
booktitle = {Frontiers in Biological Detection: From Nanosensors to Systems XVI},
editor = {Amos Danielli and Benjamin L. Miller and Sharon M. Weiss},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {128610A},
abstract = {Both the waste of edible food and the consumption of non-edible food within the best before date are ongoing concerns in food industry. Until now, no methods are applied to access food quality of packed food without opening of packages. We demonstrate the formulation of a sensor foil comprising of a non-toxic porphyrin on an inorganic matrix in polyethylene. The sensor foil is capable of detecting amines in the gas phase over food products, which could act as spoilage indicators during the shelf life of packaged food. The foil was optimized to prevent reactions with other analytes in the gas phase of food by the alteration of the hydrophobic polymer. We performed experiments, using model packing units, to monitor the behavior of the foil and correlated the change in the fluorescence spectra to the total viable count of bacteria on the fish. The readout of the foils was performed with fluorescence spectroscopy to yield highly accurate results in contrast to less accurate the colorimetric determination.},
keywords = {fluorescence spectroscopy, gas sensing, amine sensor, food safety, porphyrins},
year = {2024},
doi = {10.1117/12.3000908},
URL = {https://doi.org/10.1117/12.3000908}
}

@inproceedings{10.1117/12.3000912,
author = {Alexander Altmann and Mohammad Khodaygani and Martin Leucker and Christian Schell and Ramtin Rahmanzadeh},
title = {{Detection of spoiled food along the supply chain with novel sensors for packed food}},
volume = {12879},
booktitle = {Photonic Technologies in Plant and Agricultural Science},
editor = {Dag Heinemann and Gerrit Polder},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1287906},
abstract = {Along food supply chains, several critical steps can lead to inconsumable food. Especially food of animal origin undergoes rapid aging, when stored inadequately. Quality assessment of packaged food products faces serious problems ranging from the loss of integrity of the package to damage of the food and it is applied only to a low number of samples per batch. As a result, food products are either wasted or not analyzed, which results in a significant decrease in food safety. As a part of an intelligent packaging system, we designed a sensor foil that can detect amines, produced during the food aging process. Change of the fluorescence of the sensor foil can be assessed with spectroscopy or color change from green to red can be detected optically with a camera, e.g. by smartphone. The foil can be incorporated inside the single packaging units and noninvasively measured routinely by the store or consumer. The readout of the foils was performed with steady-state tabletop spectrometers, which were then compared to the results for readouts with different inexpensive handheld devices that could be used during real-life applications, e.g., at any step in a food supply chain.  Ideally, the single food product is linked to a single foil at the primary producer, measuring the first spectrum and connecting the data to the specific product, e.g. via distributed ledger. For a transparent process chain, QR-codes could be utilized to allow access to the freshness data along the shelf life of a single package. },
keywords = {fluorescence spectroscopy, gas sensing, amine sensor, food safety, porphyrins, SVM classifier, block chain, non-destructive food testing},
year = {2024},
doi = {10.1117/12.3000912},
URL = {https://doi.org/10.1117/12.3000912}
}

@inproceedings{10.1117/12.3005413,
author = {Noah Heldt and Cornelia Holzhausen and Martin Ahrens and Mario Pieper and Peter K{\"o}nig and Gereon H{\"u}ttmann},
title = {{Improved image quality in dynamic OCT imaging by reduced imaging time and machine learning based data evaluation}},
volume = {PC12830},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVIII},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {PC128302A},
abstract = {Dynamic Optical Coherence Tomography combines high resolution tomographic imagery with a cell specific contrast by Fourier analysis. However, the conversion from frequency space into RGB images by binning requires a priori knowledge and artifacts due to global movements provide another obstacle for in vivo application.
We could show that an automated binning based on the Neural Gas algorithm can yield the highest spectral contrast without a priori knowledge and that motion artifacts can be reduced with shorter sequence lengths. Imaging murine airways, we observed that even just 6 frames are enough to generate dOCT images without losing important image information.},
keywords = {Dynamic OCT, Optical Coherence Tomography, Airways, Artificial Intelligence},
year = {2024},
doi = {10.1117/12.3005413},
URL = {https://doi.org/10.1117/12.3005413}
}

@inproceedings{10.1117/12.3005716,
author = {Gereon Hüttmann},
title = {Mathematical model for separating signal and noise in dynamic optical coherence tomography (dOCT)},
volume = {PC12830},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVIII},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {PC1283029},
abstract = {Dynamic optical coherence tomography (dOCT) uses signal fluctuation for contrasting different cellular and acellular components in living biological tissue. The autocorrelation or Fourier transform of time series of OCT measurements are converted to a color contrast. However, a quantitative analysis is still challenging. Here we investigate theoretically, how noise of the OCT measurement influences the fluctuation spectra. Probability functions are derived for the different components in the spectra and validated by numerical simulation. With an appropriate calibration of the OCT device a separation of OCT noise and a quantification the dynamic OCT should be feasible.},
keywords = {Optical coherence tomography (OCT), Dynamic optical coherence tomography (OCT), Signal to noise, Speckle statistics, Quantification},
year = {2024},
doi = {10.1117/12.3005716},
URL = {https://doi.org/10.1117/12.3005716}
}

@inproceedings{10.1117/12.2670957,
author = {Sazgar Burhan and Nicolas Detrez and Madita G{\"o}b and Matteo Mario Bonsanto and Ralf Brinkmann and Robert Huber},
title = {{Advanced FFT-based contrast approach for MHz optical coherence elastography}},
volume = {12632},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media V},
editor = {Benjamin J. Vakoc and Maciej Wojtkowski and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1263215},
abstract = {Optical coherence elastography represents mechanical characteristics of biological tissue in so-called mechanical contrast maps. In addition to the standard intensity image, the contrast map illustrates numerous mechanical tissue features that would otherwise be undetectable. This is of great interest as abnormal physiological changes influence the mechanical behavior of the tissue. We demonstrate an advanced mechanical contrast approach based on the phase signal of our 3.2 MHz optical coherence tomography system. The robustness and performance of this contrast approach is evaluated and discussed based on preliminary results. },
keywords = {Optical Coherence Tomography, OCT, Megahertz OCT, Fourier Domain Mode Locking, Optical Coherence Elastography, OCE, Phase-sensitive OCT, Biomechanics},
year = {2023},
doi = {10.1117/12.2670957},
URL = {https://doi.org/10.1117/12.2670957}
}

@inproceedings{10.1117/12.2670950,
author = {Madita G{\"o}b and Simon Lotz and Linh Ha-Wissel and Sazgar Burhan and Sven B{\"o}ttger and Floris Ernst and Jennifer Hundt and Robert Huber},
title = {{Advances in large area robotically assisted OCT (LARA-OCT): towards drive-by continuous motion imaging}},
volume = {12632},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media V},
editor = {Benjamin J. Vakoc and Maciej Wojtkowski and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {126321N},
abstract = {Optical coherence tomography is a powerful imaging technique to visualize and localize depth-dependent tissue structure to differentiate between healthy and pathological conditions. However, conventional OCT systems are only capable of detecting small areas. To overcome this limitation, we have developed a large area robotically assisted OCT (LARA-OCT) system for automatic acquisition of large OCT images. Using mosaic pattern acquisition and subsequent stitching, we previously demonstrated initial in vivo OCT skin images beyond 10 cm². To improve acquisition speed and reduce dead times, we here demonstrate and analyze LARA-OCT with a new drive-by continuous motion imaging protocol.},
keywords = {Optical Coherence Tomography, Fourier Domain Mode Locking, Robotically Assisted Imaging Systems, Three-dimensional image acquisition, Large Area Scanning, Skin Imaging, OCT, FDML},
year = {2023},
doi = {10.1117/12.2670950},
URL = {https://doi.org/10.1117/12.2670950}
}

@inproceedings{10.1117/12.2670907,
author = {Paul Strenge and Birgit Lange and Wolfgang Draxinger and Christian Hagel and Christin Grill and Veit Danicke and Dirk Theisen-Kunde and Sonja Spahr-Hess and Matteo M. Bonsanto and Robert Huber and Heinz Handels and Ralf Brinkmann},
title = {{Demarcation of brain and tumor tissue with optical coherence tomography using prior neural networks}},
volume = {12632},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media V},
editor = {Benjamin J. Vakoc and Maciej Wojtkowski and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {126321P},
keywords = {Brain Tumor, OCT, Optical Coherence Tomography, Prior Network, Glioblastoma Multiforme, Neural Network, Classification},
year = {2023},
doi = {10.1117/12.2670907},
URL = {https://doi.org/10.1117/12.2670907}
}

@inproceedings{10.1117/12.2670953,
author = {Wolfgang Draxinger and Dirk Theisen-Kunde and Lion Schuetz and Nicolas Detrez and Paul Strenge and Maximilian Rixius and Veit Danicke and Wolfgang Wieser and Jessica Kren and Patrick Kuppler and Sonja Spar-Hess and Matteo Mario Bonsanto M.D. and Ralf Brinkmann and Robert Huber},
title = {{Microscope integrated realtime high density 4D MHz-OCT in neurosurgery: a depth and tissue resolving visual contrast channel and the challenge of fused presentation}},
volume = {12627},
booktitle = {Translational Biophotonics: Diagnostics and Therapeutics III},
editor = {Zhiwei Huang and Lothar D. Lilge},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {126270W},
abstract = {Microscope integrated realtime 4D MHz-OCT operating at high scanning densities are capable of capturing additional visual contrast resolving depth and tissue. Even within a plain C-scan en-face projection structures are recognizable, that are not visible in a white light camera image. With advanced post processing methods, such as absorbtion coefficient mapping, and morphological classifiers more information is extraced. Presentation to the user in an intuitive way poses practical challenges that go beyond the implementation of a mere overlay display. We present our microscope integrated high speed 4D OCT imaging system, its clinical study use for in-vivo brain tissue imaging, and user feedback on the presentation methods we developed.},
keywords = {optical coherence tomography, neurosurgery, tissue contrast, image fusion, surgical guidance, theranostics},
year = {2023},
doi = {10.1117/12.2670953},
URL = {https://doi.org/10.1117/12.2670953}
}

@INPROCEEDINGS{10231419,
  author={Lotz, Simon and Göb, Madita and Draxinger, Wolfgang and Dick, Anneli and Huber, Robert},
  booktitle={2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)}, 
  title={13.4 MHz FDML Laser for Intra-Surgical Optical Coherence Tomography}, 
  year={2023},
  volume={},
  number={},
  pages={1-1},
  doi={10.1109/CLEO/Europe-EQEC57999.2023.10231419}}

@INPROCEEDINGS{10232019,
  author={Klufts, M. and Lotz, S. and Bashir, M. A. and Pfeiffer, T. and Mlynek, A. and Wieser, W. and Chamorovskiy, A. and Shidlovski, V. and Podoleanu, A. and Huber, R.},
  booktitle={2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)}, 
  title={Dual Amplification 850 nm FDML Laser}, 
  year={2023},
  volume={},
  number={},
  pages={1-1},
  doi={10.1109/CLEO/Europe-EQEC57999.2023.10232019}}

@INPROCEEDINGS{10232141,
  author={Lamminger, Philipp and Hakert, Hubertus and Lotz, Simon and Kolb, Jan Philip and Kutscher, Tonio and Karpf, Sebastian and Huber, Robert},
  booktitle={2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)}, 
  title={Four-Wave Mixing Fast Wavelength Sweeping FDML Laser with kW Peak Power at 900 nm and 1300 nm}, 
  year={2023},
  volume={},
  number={},
  pages={1-1},
  doi={10.1109/CLEO/Europe-EQEC57999.2023.10232141}}

@INPROCEEDINGS{10232661,
  author={Bashir, M. A. and Lotz, S. and Kluftsa, M. and Jirauschek, C. and Huberab, R.},
  booktitle={2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)}, 
  title={1190 nm FDML laser: Challenges and Strategies}, 
  year={2023},
  volume={},
  number={},
  pages={1-1},
  doi={10.1109/CLEO/Europe-EQEC57999.2023.10232661}}

@inproceedings{10.1117/12.2648505,
author = {Wolfgang Draxinger and Dirk Theisen-Kunde and Lion Sch{\"u}tzeck and Nicolas Detrez and Paul Strenge and Veit Danicke and Jessica Kren and Patrick Kuppler and Sonja Spahr-Hess and Matteo Mario Bonsanto and Ralf Brinkmann and Robert Huber},
title = {{High speed 4D in-vivo OCT imaging of the human brain: creating high density datasets for machine learning toward identification of malign tissue in real time}},
volume = {12390},
booktitle = {High-Speed Biomedical Imaging and Spectroscopy VIII},
editor = {Kevin K. Tsia and Keisuke Goda},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {123900D},
abstract = {Neuro-surgery is challenged by the difficulties of determining brain tumor boundaries during excisions. Optical coherence tomography is investigated as an imaging modality for providing a viable contrast channel. Our MHz-OCT technology enables rapid volumetric imaging, suitable for surgical workflows. We present a surgical microscope integrated MHz-OCT imaging system, which is used for the collection of in-vivo images of human brains, with the purpose of being used in machine learning systems that shall be trained to identify and classify tumorous tissue.},
keywords = {optical coherence tomography, brain tumor, neurosurgery, machine learning, contrast augmentation, histology dataset, clinical study, in-vivo imaging},
year = {2023},
doi = {10.1117/12.2648505},
URL = {https://doi.org/10.1117/12.2648505}
}

@inproceedings{10.1117/12.2652884,
author = {M. A. Bashir and S. Lotz and M. Klufts and I. Krestnikov and C. Jirauschek and R. Huber},
title = {{1190 nm Fourier domain mode locked (FDML) laser for optical coherence tomography (OCT)}},
volume = {12367},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1236707},
abstract = {We demonstrate a Fourier domain mode locked (FDML) laser centered at 1190 nm with 2×410 kHz sweep repetition rate, a sweeping range of 100 nm and 2.5 mW output power. The laser is based on a quantum dot-semiconductor optical amplifier with small linewidth enhancement factor. The laser could be used as a probe laser in stimulated Raman scattering microscopy and it may be attractive for optical coherence tomography due to low water absorption and the spectral signature of lipids around 1200nm. Moreover, it is ideal to close the gap between FDML lasers at 1064 nm and 1300 nm. Combining these three lasers can enable ultrawideband sweeping to improve the axial OCT resolution down to 2 μm. },
keywords = {FDML, Swept source, laser, SS-OCT, OCT, Tunable lasers},
year = {2023},
doi = {10.1117/12.2652884},
URL = {https://doi.org/10.1117/12.2652884}
}

@inproceedings{10.1117/12.2649646,
author = {M. Klufts and S. Lotz and M. A. Bashir and T. Pfeiffer and A. Mlynek and W. Wieser and A. Chamorovskiy and V. Shidlovski and R. Huber},
title = {{850 nm FDML: performance and challenges}},
volume = {12367},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1236705},
abstract = {We demonstrate a Fourier domain mode locked (FDML) laser centered around 850 nm with a sweeping range of 50 nm, a fundamental repetition rate of 2×416 kHz and an output power of 2 mW. A new cavity design using three chirped Fiber Bragg gratings is required to overcome sweeping limitations caused by high dispersion. Other solutions to address challenges such as high loss and high polarization mode dispersion will be discussed along with performance. A main application of this laser will be retinal imaging, but it might also be applicable for TiCo-Raman and SLIDE microscopy. },
keywords = {Swept source, FDML, Laser, Ophthalmic imaging, OCT, 800 nm, retinal imaging, light sources},
year = {2023},
doi = {10.1117/12.2649646},
URL = {https://doi.org/10.1117/12.2649646}
}

@inproceedings{10.1117/12.2649663,
author = {Philipp Lamminger and Hubertus Hakert and Simon Lotz and Jan Philip Kolb and Tonio Kutscher and Sebastian Karpf and Robert Huber},
title = {{900 nm swept source FDML laser with kW peak power}},
volume = {12400},
booktitle = {Fiber Lasers XX: Technology and Systems},
editor = {V.  R. Supradeepa},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {124001I},
abstract = {A wavelength agile 900 nm 2.5 kW peak power fiber laser is created by four-wave mixing (FWM) in a photonic crystal fiber (PCF), while amplifying a 1300 nm Fourier-domain mode-locked (FDML) laser. The FWM process is pumped by a home-built 1064 nm master oscillator power amplifier (MOPA) laser and seeded by a home-built 1300 nm FDML laser, generating high power pulses at wavelengths, where amplification by active fiber media is difficult. The 900 nm pulses have a spectral linewidth of 70 pm, are tunable over 54 nm and have electronic pulse-to-pulse tuning capability. These pulses can be used for nonlinear imaging like two-photon or coherent anti-Stokes Raman microscopy (CARS) microscopy including spectro-temporal laser imaging by diffracted excitation (SLIDE) and time-encoded (Tico) stimulated Raman microscopy.},
keywords = {Fourier domain mode locking,  FDML, Raman, two photon microscopy, SLIDE, 900 nm, fiber laser, photonic crystal fiber, swept source},
year = {2023},
doi = {10.1117/12.2649663},
URL = {https://doi.org/10.1117/12.2649663}
}

@inproceedings{10.1117/12.2648301,
author = {Sazgar Burhan and Nicolas Detrez and Katharina Rewerts and Madita G{\"o}b and Christian Hagel and Matteo Mario Bonsanto and Dirk Theisen-Kunde and Robert Huber and Ralf Brinkmann},
title = {{Characterization of brain tumor tissue by time-resolved, phase-sensitive optical coherence elastography at 3.2 MHz line rate}},
volume = {12368},
booktitle = {Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XXI},
editor = {Caroline Boudoux and James W. Tunnell},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {123680F},
abstract = {Optical coherence elastography (OCE) offers the possibility of obtaining the mechanical behavior of a tissue. When also  using a non-contact mechanical excitation, it mimics palpation without interobserver variability. One of the most frequently  used techniques is phase-sensitive OCE. Depending on the system, depth-resolved changes in the sub-µm to nm range can  be detected and visualized volumetrically. Such an approach is used in this work to investigate and detect transitions  between healthy and tumorous brain tissue as well as inhomogeneities in the tumor itself to assist the operating surgeon  during tumor resection in the future. We present time-resolved, phase-sensitive OCE measurements on various ex vivo brain tumor samples using an ultra-fast 3.2 MHz swept-source optical coherence tomography (SS-OCT) system with a frame rate of 2.45 kHz. 4 mm line scans are acquired which, in combination with the high imaging speed, allow monitoring and investigation of the sample's behavior in response to the mechanical load. Therefore, an air-jet system applies a 200 ms  short air pulse to the sample, whose non-contact property facilitates the possibility for future in vivo measurements. Since we can temporally resolve the response of the sample over the entire acquisition time, the mechanical properties are evaluated at different time points with depth resolution. This is done by unwrapping the phase data and performing subsequent assessment. Systematic ex vivo brain tumor measurements were conducted and visualized as distribution maps.  The study outcomes are supported by histological analyses and examined in detail.},
keywords = { Optical Coherence Tomography, Optical Coherence Elastography, Phase-sensitive OCT, Fourier Domain Mode Locking, Brain Tumor, Phase Unwrapping, Tissue Characterization, Biomechanics},
year = {2023},
doi = {10.1117/12.2648301},
URL = {https://doi.org/10.1117/12.2648301}
}