OCT is a noninvasive Imaging modality which is typically used for high resolution (~10µm), three dimensional imaging of scattering tissue. By using home built FDML laser technology we achieve imaging speeds of several million depth scans per second, which is one to two orders of magnitude higher than current commercially available systems (MHz-OCT).
These high imaging speeds already proved to be very useful in clinical applications, by reducing acquisition times and therefore reducing motion artifacts. But the high speed also gives access to the phase of the detected light and will thus allow the use of new numerical approaches for image quality enhancement and functional imaging with Swept-Source-OCT.
Our working group is conducting research in the field of OCT to develop new technologies and to identify possible fields of application.
The focus areas are:
- MHz-OCT - Ultra-fast OCT imaging with several million depth scans per second
- LARA-OCT - Large area robotically assisted OCT
- VR-OCT - Real-time computation and rendering of entire OCT volumes in a virtual environment
- Eye OCT - application of MHz-OCT to the eye for visualization of the retina or the anterior segment of the eye
- Phase sensitive OCT - enhancement of the information content of an OCT image by adding phase contrast
- Multispectral OCT - combination of RGB and OCT images for improved visualization of morphological structures
related Publications
2011
FDML laser for megahertz retinal OCT imaging, in CLEO:2011 - Laser Applications to Photonic Applications , Optica Publishing Group, 062011. pp. CWB1.
DOI: | 10.1364/CLEO_SI.2011.CWB1 |
Bibtex: | @inproceedings{Klein:11, author = {Thomas Klein and Wolfgang Wieser and Benjamin R. Biedermann and Christoph M. Eigenwillig and Robert Huber}, booktitle = {CLEO:2011 - Laser Applications to Photonic Applications}, journal = {CLEO:2011 - Laser Applications to Photonic Applications}, keywords = {Optical coherence tomography; Lasers, tunable; Image quality; Imaging techniques; Laser modes; Medical imaging; Mode locking; Optical coherence tomography}, pages = {CWB1}, publisher = {Optica Publishing Group}, title = {FDML laser for megahertz retinal OCT imaging}, year = {2011}, url = {https://opg.optica.org/abstract.cfm?URI=CLEO_SI-2011-CWB1}, doi = {10.1364/CLEO_SI.2011.CWB1}, abstract = {A novel Fourier-domain mode locked (FDML) laser design is presented, yielding the highest wavelength sweep speed reported so far around 1050nm. This enables retinal imaging over a ~70{\textdegree} ultra-wide field of view.}, } |
Extended focus high-speed swept source OCT with self-reconstructive illumination, Opt. Express , vol. 19, no. 13, pp. 12141-12155, 06 2011. Optica Publishing Group.
DOI: | 10.1364/OE.19.012141 |
Bibtex: | @article{Blatter:11, author = {Cedric Blatter and Branislav Grajciar and Christoph M. Eigenwillig and Wolfgang Wieser and Benjamin R. Biedermann and Robert Huber and Rainer A. Leitgeb}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Optical coherence tomography; Flow diagnostics; Coherence tomography ; Functional monitoring and imaging ; Functional imaging; Image quality; Imaging techniques; In vivo imaging; Optical imaging; Three dimensional imaging}, number = {13}, pages = {12141--12155}, publisher = {Optica Publishing Group}, title = {Extended focus high-speed swept source OCT with self-reconstructive illumination}, volume = {19}, month = {Jun}, year = {2011}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-19-13-12141}, doi = {10.1364/OE.19.012141}, abstract = {We present a Bessel beam illumination FDOCT setup using a FDML Swept Source at 1300nm with up to 440kHz A-scan rate, and discuss its advantages for structural and functional imaging of highly scattering samples. An extended focus is achieved due to the Bessel beam that preserves its lateral extend over a large depth range. Furthermore, Bessel beams exhibit a self-reconstruction property that allows imaging even behind obstacles such as hairs on skin. Decoupling the illumination from the Gaussian detection increases the global sensitivity and enables dark field imaging. Dark field imaging is useful to avoid strong reflexes from the sample surface that adversely affect the sensitivity due to the limited dynamic range of high speed 8bit acquisition cards. In addition the possibility of contrasting capillaries with high sensitivity is shown, using inter-B-scan speckle variance analysis. We demonstrate intrinsic advantages of the extended focus configuration, in particular the reduction of the phase decorrelation effect below vessels leading to improved axial vessel definition.}, } |
Structural and functional imaging with extended focus dark-field OCT at 1300nm, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XV , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, 022011. pp. 78891D.
DOI: | 10.1117/12.875594 |
Bibtex: | @inproceedings{10.1117/12.875594, author = {Cedric Blatter and Branislav Grajciar and Robert Huber and Rainer A. Leitgeb}, title = {{Structural and functional imaging with extended focus dark-field OCT at 1300nm}}, volume = {7889}, booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XV}, editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin}, organization = {International Society for Optics and Photonics}, publisher = {SPIE}, pages = {78891D}, abstract = {We present an extended focus FDOCT setup with FDML swept source centered at 1310nm. The illumination, preserving its lateral extend over a large depth range thanks to the use of a Bessel beam, is decoupled from the Gaussian detection in order to increase the global sensitivity. The efficient spatial separation enables dark-field imaging. In-vivo measurements in the skin were performed to demonstrate the gain in lateral resolution while preserving the imaging depth. More, the calculation of the speckle variance between B-Scans allows a clear visualization of the microvasculature.}, keywords = {Extended focus, Dark Field imaging, Bessel beam, FDML Swept Source, dermatology, microvascularisation imaging}, year = {2011}, doi = {10.1117/12.875594}, URL = {https://doi.org/10.1117/12.875594} } |
Megahertz OCT for ultrawide-field retinal imaging with a 1050 nm Fourier domain mode-locked laser, Opt. Express , vol. 19, no. 4, pp. 3044--3062, 02 2011. Optica Publishing Group.
DOI: | 10.1364/OE.19.003044 |
Bibtex: | @article{Klein:11, author = {Thomas Klein and Wolfgang Wieser and Christoph M. Eigenwillig and Benjamin R. Biedermann and Robert Huber}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Lasers, tunable; Imaging systems; Ophthalmology; Optical coherence tomography; Retina scanning ; Fiber lasers; Image processing; Image quality; Mode locking; Ophthalmic imaging; Three dimensional imaging}, number = {4}, pages = {3044--3062}, publisher = {Optica Publishing Group}, title = {Megahertz OCT for ultrawide-field retinal imaging with a 1050nm Fourier domain mode-locked laser}, volume = {19}, month = {Feb}, year = {2011}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-19-4-3044}, doi = {10.1364/OE.19.003044}, abstract = {We demonstrate ultrahigh speed swept source retinal OCT imaging using a Fourier domain mode locked (FDML) laser. The laser uses a combination of a semiconductor optical amplifier and an ytterbium doped fiber amplifier to provide more than 50mW output power. The 1050nm FDML laser uses standard telecom fiber for the km long delay line instead of two orders of magnitude more expensive real single mode fiber. We investigate the influence of this ``oligo-mode'' fiber on the FDML laser performance. Two design configurations with 684,400 and 1,368,700 axial scans per second are investigated, 25x and 50x faster than current commercial instruments and more than 4x faster than previous single spot ophthalmic results. These high speeds enable the acquisition of densely sampled ultrawide-field data sets of the retina within a few seconds. Ultrawide-field data consisting of 1900 x 1900 A-scans with ~70{\textdegree} degrees angle of view are acquired within only 3 and 6 seconds using the different setups. Such OCT data sets, more than double as large as previously reported, are collapsed to a 4 megapixel high definition fundus image. We achieve good penetration into the choroid by hardware spectral shaping of the laser output. The axial resolution in tissue is 12{\textmu}m (684kHz) and 19{\textmu}m (1.37MHz). A series of new data processing and imaging extraction protocols, enabled by the ultrawide-field isotropic data sets, are presented. Dense isotropic sampling enables both, cross-sectional images along arbitrary coordinates and depth-resolved en-face fundus images. Additionally, we investigate how isotropic averaging compares to the averaging of cross-sections along the slow axis.}, } |
3D optical coherence tomography for clinical diagnosis of nonmelanoma skin cancers, Imaging in Medicine , vol. 3, no. 6, pp. 653-674, 2011.
Weblink: | https://www.openaccessjournals.com/articles/3d-optical-coherence-tomography-for-clinical-diagnosis-of-nonmelanoma-skin-cancers-9179.html |
Bibtex: | @article{Alex2011, author = {Alex, A. and Weingast, J. and Hofer, B. and Eibl, M. and Binder, M. and Pehamberger, H. and Drexler, W. and Považay, B.}, title = {3D optical coherence tomography for clinical diagnosis of nonmelanoma skin cancers}, journal = {Imaging in Medicine}, volume = {3}, number = {6}, keyword = {cancer diagnosis, contrast-enhanced imaging, dermatology, functional imaging,microscopy, multimodal imaging, optical coherence tomography, optical imaging, tomography}, abstract = {High-resolution frequency domain optical coherence tomography (OCT) stands out amongst a range of novel dermatologic imaging technologies, with its good detection sensitivity around-100 dB, high measurement speeds allowing real-time image acquisition and its ability to acquire high definition cross-sectional and 3D tomograms of regions greater than 1 cm2, providing tissue information comparable to conventional histopathology without the need for any contrast agents. Typical axial and transverse resolutions of state-of-the-art OCT systems range between 1-10 m and approximately 20 m, respectively, depending on the employed wavelength region. This review investigates the significant progress accomplished in the field of dermatologic OCT with respect to other in vivo diagnostic methods for pre-excisional imaging of nonmelanoma skin cancers and specifically emphasizes state-of-the-art results achieved in different clinical pilot studies. Further technological extensions of OCT, various multimodal imaging approaches as well as potential clinical dermatologic applications are discussed. © 2011 Future Medicine Ltd.}, pages = {653-674}, url = {https://www.openaccessjournals.com/articles/3d-optical-coherence-tomography-for-clinical-diagnosis-of-nonmelanoma-skin-cancers-9179.html}, year = {2011}, keywords = {AG-Huber, OCT}, type = {Journal Article} } |
2010
High-Quality 3-D Imaging with Multimegahertz OCT, Opt. Photon. News , vol. 21, no. 12, pp. 28-29, Dec. 2010. Optica Publishing Group.
DOI: | 10.1364/OPN.21.12.000028 |
Bibtex: | @article{Wieser:10, author = {Wolfgang Wieser and Benjamin R. Biedermann and Thomas Klein and Christoph M. Eigenwillig and Robert Huber}, journal = {Opt. Photon. News}, keywords = {General; Analog to digital converters; Crystallography; Image quality; Optical coherence tomography; Real time imaging; Three dimensional imaging}, number = {12}, pages = {28--28}, publisher = {Optica Publishing Group}, title = {High-Quality 3-D Imaging withMultimegahertz OCT}, volume = {21}, month = {Dec}, year = {2010}, url = {https://www.optica-opn.org/abstract.cfm?URI=opn-21-12-28}, doi = {10.1364/OPN.21.12.000028}, abstract = {We have developed interferometric systems to measure nanosize structures and freeze their motion in time. Researchers have also suggested a method to extract both phase and amplitude information for crystallography.}, } |
Direct measurement of the instantaneous linewidth of rapidly wavelength-swept lasers, Opt. Lett. , vol. 35, no. 22, pp. 3733-3735, Nov. 2010. Optica Publishing Group.
DOI: | 10.1364/OL.35.003733 |
Bibtex: | @article{Biedermann:10, author = {Benjamin R. Biedermann and Wolfgang Wieser and Christoph M. Eigenwillig and Thomas Klein and Robert Huber}, journal = {Opt. Lett.}, keywords = {Optical coherence tomography; Lasers, tunable; Electrooptical modulators; Fourier transforms; Laser light; Laser sources; Optical coherence tomography; Swept lasers}, number = {22}, pages = {3733--3735}, publisher = {Optica Publishing Group}, title = {Direct measurement of the instantaneous linewidth of rapidly wavelength-swept lasers}, volume = {35}, month = {Nov}, year = {2010}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-35-22-3733}, doi = {10.1364/OL.35.003733}, abstract = {The instantaneous linewidth of rapidly wavelength-swept laser sources as used for optical coherence tomography (OCT) is of crucial interest for a deeper understanding of physical effects involved in their operation. Swept lasers for OCT, typically sweeping over ~15 THz in ~10$\mu$s, have linewidths of several gigahertz. The high optical-frequency sweep speed makes it impossible to measure the instantaneous spectrum with standard methods. Hence, up to now, experimental access to the instantaneous linewidth was rather indirect by the inverse Fourier transform of the coherence decay. In this Letter, we present a method by fast synchronous time gating and extraction of a ``snapshot'' of the instantaneous spectrum with an electro-optic modulator, which can subsequently be measured with an optical spectrum analyzer. This new method is analyzed in detail, and systematic artifacts, such as sideband generation due to the modulation and residual wavelength uncertainty due to the sweeping operation, are quantified. The method is checked for consistency with results from the common, more indirect measurement via coherence properties.}, } |
Fourier domain mode-locked swept source at 1050 nm based on a tapered amplifier, Opt. Express , vol. 18, no. 15, pp. 15820-15831, 07 2010. Optica Publishing Group.
DOI: | 10.1364/OE.18.015820 |
Bibtex: | @article{Marschall:10, author = {Sebastian Marschall and Thomas Klein and Wolfgang Wieser and Benjamin R. Biedermann and Kevin Hsu and Kim P. Hansen and Bernd Sumpf and Karl-Heinz Hasler and G\"{o}tz Erbert and Ole B. Jensen and Christian Pedersen and Robert Huber and Peter E. Andersen}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Lasers, tunable; Semiconductor lasers; Semiconductor optical amplifiers; Dispersion; High speed imaging; Laser light; Optical delay lines; Optical fibers; Optical standards; Swept sources}, number = {15}, pages = {15820--15831}, publisher = {Optica Publishing Group}, title = {Fourier domain mode-locked swept source at 1050 nm based on a tapered amplifier}, volume = {18}, month = {Jul}, year = {2010}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-18-15-15820}, doi = {10.1364/OE.18.015820}, abstract = {While swept source optical coherence tomography (OCT) in the 1050 nm range is promising for retinal imaging, there are certain challenges. Conventional semiconductor gain media have limited output power, and the performance of high-speed Fourier domain mode-locked (FDML) lasers suffers from chromatic dispersion in standard optical fiber. We developed a novel light source with a tapered amplifier as gain medium, and investigated the FDML performance comparing two fiber delay lines with different dispersion properties. We introduced an additional gain element into the resonator, and thereby achieved stable FDML operation, exploiting the full bandwidth of the tapered amplifier despite high dispersion. The light source operates at a repetition rate of 116 kHz with an effective average output power in excess of 30 mW. With a total sweep range of 70 nm, we achieved an axial resolution of 15 {\textmu}m in air (~11 {\textmu}m in tissue) in OCT measurements. As our work shows, tapered amplifiers are suitable gain media for swept sources at 1050 nm with increased output power, while high gain counteracts dispersion effects in an FDML laser.}, } |
Multi-megahertz OCT: High quality 3D imaging at 20 million A-scans and 4.5 GVoxels per second, Opt. Express , vol. 18, no. 14, pp. 14685-14704, 07 2010. Optica Publishing Group.
DOI: | 10.1364/OE.18.014685 |
Bibtex: | @article{Wieser:10, author = {Wolfgang Wieser and Benjamin R. Biedermann and Thomas Klein and Christoph M. Eigenwillig and Robert Huber}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Three-dimensional image acquisition; Lasers, tunable; Optical coherence tomography; Biological imaging; High speed imaging; Image processing algorithms; Image quality; Point spread function; Three dimensional imaging}, number = {14}, pages = {14685--14704}, publisher = {Optica Publishing Group}, title = {Multi-Megahertz OCT: High quality 3D imaging at 20 million A-scans and 4.5 GVoxels per second}, volume = {18}, month = {Jul}, year = {2010}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-18-14-14685}, doi = {10.1364/OE.18.014685}, abstract = {We present ultra high speed optical coherence tomography (OCT) with multi-megahertz line rates and investigate the achievable image quality. The presented system is a swept source OCT setup using a Fourier domain mode locked (FDML) laser. Three different FDML-based swept laser sources with sweep rates of 1, 2.6 and 5.2MHz are compared. Imaging with 4 spots in parallel quadruples the effective speed, enabling depth scan rates as high as 20.8 million lines per second. Each setup provides at least 98dB sensitivity and ~10{\textmu}m resolution in tissue. High quality 2D and 3D imaging of biological samples is demonstrated at full scan speed. A discussion about how to best specify OCT imaging speed is included. The connection between voxel rate, line rate, frame rate and hardware performance of the OCT setup such as sample rate, analog bandwidth, coherence length, acquisition dead-time and scanner duty cycle is provided. Finally, suitable averaging protocols to further increase image quality are discussed.}, } |
High-power FDML laser for swept source-OCT at 1060 nm, in Biophotonics: Photonic Solutions for Better Health Care II , Jürgen Popp and Wolfgang Drexler and Valery V. Tuchin and Dennis L. Matthews, Eds. SPIE, 052010. pp. 77150B.
DOI: | 10.1117/12.854238 |
Bibtex: | @inproceedings{10.1117/12.854238, author = {Sebastian Marschall and Thomas Klein and Wolfgang Wieser and Benjamin Biedermann and Kevin Hsu and Bernd Sumpf and Karl-Heinz Hasler and G{\"o}tz Erbert and Ole B. Jensen and Christian Pedersen and Robert Huber and Peter E. Andersen}, title = {{High-power FDML laser for swept source-OCT at 1060 nm}}, volume = {7715}, booktitle = {Biophotonics: Photonic Solutions for Better Health Care II}, 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 = {77150B}, abstract = {We present a novel frequency-swept light source working at 1060nm that utilizes a tapered amplifier as gain medium. These devices feature significantly higher saturation power than conventional semiconductor optical amplifiers and can thus improve the limited output power of swept sources in this wavelength range. We demonstrate that a tapered amplifier can be integrated into a fiber-based swept source and allows for high-speed FDML operation. The developed light source operates at a sweep rate of 116kHz with an effective average output power in excess of 30mW. With a total sweep range of 70 nm an axial resolution of 15 μm in air (~11μm in tissue) for OCT applications can be achieved.}, keywords = {optical coherence tomography, swept source, tunable laser, tapered amplifier, fourier domain mode-locking}, year = {2010}, doi = {10.1117/12.854238}, URL = {https://doi.org/10.1117/12.854238} } |
Linewidth Optimization of Fourier Domain Mode-Locked Lasers, Conference on Lasers and Electro-Optics 2010 , pp. CMW7, 05 2010. Optica Publishing Group.
DOI: | 10.1364/CLEO.2010.CMW7 |
Bibtex: | @inproceedings{Todor:10, author = {Sebastian Todor and Christian Jirauschek and Benjamin Biedermann and Robert Huber}, booktitle = {Conference on Lasers and Electro-Optics 2010}, journal = {Conference on Lasers and Electro-Optics 2010}, keywords = {Lasers and laser optics; Laser theory; Lasers, tunable; Laser light; Laser operation; Mode locking; Optical amplifiers; Self phase modulation; Tunable lasers}, pages = {CMW7}, publisher = {Optica Publishing Group}, title = {Linewidth Optimization of Fourier Domain Mode-Locked Lasers}, year = {2010}, url = {https://opg.optica.org/abstract.cfm?URI=CLEO-2010-CMW7}, doi = {10.1364/CLEO.2010.CMW7}, abstract = {We theoretically and experimentally investigate the instantaneous linewidth of Fourier domain mode-locked lasers, yielding good agreement. Based on simulations, strategies are discussed to drastically reduce the laser linewidth.}, } |
FDML swept source at 1060 nm using a tapered amplifier, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIV , Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin, Eds. International Society for Optics and Photonics, 022010. pp. 75541H.
DOI: | 10.1117/12.842011 |
Bibtex: | @inproceedings{10.1117/12.842011, author = {Sebastian Marschall and Thomas Klein and Wolfgang Wieser and Benjamin Biedermann and Kevin Hsu and Bernd Sumpf and Karl-Heinz Hasler and G{\"o}tz Erbert and Ole B. Jensen and Christian Pedersen and Robert Huber and Peter E. Andersen}, title = {{FDML swept source at 1060 nm using a tapered amplifier}}, volume = {7554}, booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIV}, editor = {Joseph A. Izatt and James G. Fujimoto and Valery V. Tuchin}, organization = {International Society for Optics and Photonics}, publisher = {SPIE}, pages = {75541H}, abstract = {We present a novel frequency-swept light source working at 1060nm that utilizes a tapered amplifier as gain medium. These devices feature significantly higher saturation power than conventional semiconductor optical amplifiers and can thus improve the limited output power of swept sources in this wavelength range. We demonstrate that a tapered amplifier can be integrated into a fiber-based swept source and allows for high-speed FDML operation. The developed light source operates at a sweep rate of 116kHz with an effective average output power in excess of 30mW. With a total sweep range of 70 nm an axial resolution of 15 μm in air (~11μm in tissue) for OCT applications can be achieved.}, keywords = {optical coherence tomography, swept source, tunable laser, tapered amplifier, fourier domain mode-locking}, year = {2010}, doi = {10.1117/12.842011}, URL = {https://doi.org/10.1117/12.842011} } |
2009
Advances in Fourier domain OCT, in 2009 IEEE LEOS Annual Meeting Conference Proceedings , IEEE, Oct.2009. pp. 201-202.
DOI: | 10.1109/LEOS.2009.5343314 |
Bibtex: | @INPROCEEDINGS{5343314, author={Huber, Robert}, booktitle={2009 IEEE LEOS Annual Meeting Conference Proceedings}, title={Advances in Fourier domain OCT}, year={2009}, volume={}, number={}, pages={201-202}, abstract={In optical coherence tomography, the introduction of so called ldquoFrequency Domainrdquo techniques, i.e. spectrally resolved detection, had a dramatic impact on these biomedical imaging systems. The current status and future developments will be discussed.}, keywords={}, doi={10.1109/LEOS.2009.5343314}, ISSN={1092-8081}, month={Oct},} |
Ultra high-speed swept source OCT imaging of the anterior segment of human eye at 200 kHz with adjustable imaging range, Opt. Express , vol. 17, no. 17, pp. 14880-14894, 08 2009. Optica Publishing Group.
DOI: | 10.1364/OE.17.014880 |
Bibtex: | @article{Gora:09, author = {Michalina Gora and Karol Karnowski and Maciej Szkulmowski and Bartlomiej J. Kaluzny and Robert Huber and Andrzej Kowalczyk and Maciej Wojtkowski}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Lasers, tunable; Ophthalmology; Crystalline lens; High speed imaging; Imaging systems; Ophthalmic imaging; Optical coherence tomography; Three dimensional imaging}, number = {17}, pages = {14880--14894}, publisher = {Optica Publishing Group}, title = {Ultra high-speed swept source OCT imaging of the anterior segment of human eye at 200 kHz with adjustable imaging range}, volume = {17}, month = {Aug}, year = {2009}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-17-17-14880}, doi = {10.1364/OE.17.014880}, abstract = {We present an application of in vivo anterior segment imaging of the human eye with an ultrahigh speed swept source OCT instrument. For this purpose, a dedicated OCT system was designed and constructed. This instrument enables axial zooming by automatic reconfiguration of spectral sweep range; an enhanced imaging range mode enables imaging of the entire anterior segment while a high axial resolution mode provides detailed morphological information of the chamber angle and the cornea. The speed of 200,000 lines/s enables high sampling density in three-dimensional imaging of the entire cornea in 250 ms promising future applications of OCT for optical corneal topography, pachymetry and elevation maps. The results of a preliminary quantitative corneal analysis based on OCT data free form motion artifacts are presented. Additionally, a volumetric and real time reconstruction of dynamic processes, like pupillary reaction to light stimulus or blink-induced contact lens movements are demonstrated.}, } |
Recent developments in Fourier domain mode locked lasers for optical coherence tomography: imaging at 1310 nm vs. 1550 nm wavelength, Journal of Biophotonics , vol. 2, no. 6-7, pp. 357-363, 07 2009.
DOI: | 10.1002/jbio.200910028 |
Bibtex: | @article{https://doi.org/10.1002/jbio.200910028, author = {Biedermann, Benjamin R. and Wieser, Wolfgang and Eigenwillig, Christoph M. and Huber, Robert}, title = {Recent developments in Fourier Domain Mode Locked lasers for optical coherence tomography: Imaging at 1310 nm vs. 1550 nm wavelength}, journal = {Journal of Biophotonics}, volume = {2}, number = {6-7}, pages = {357-363}, keywords = {optical coherence tomography, tunable lasers, Fourier domain mode locking, optical frequency domain imaging}, doi = {https://doi.org/10.1002/jbio.200910028}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jbio.200910028}, eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1002/jbio.200910028}, abstract = {Abstract We report on recent progress in Fourier domain mode-locking (FDML) technology. The paper focuses on developments beyond pushing the speed of these laser sources. After an overview of improvements to FDML over the last three years, a brief analysis of OCT imaging using FDML lasers with different wavelengths is presented. For the first time, high speed, high quality FDML imaging at 1550 nm is presented and compared to a system at 1310 nm. The imaging results of human skin for both wavelengths are compared and analyzed. Sample arm optics, power on the sample, heterodyne gain, detection bandwidth, colour cut levels and sample location have been identical to identify the influence of difference in scattering and water absorption. The imaging performance at 1310 nm in human skin is only slightly better and the results suggest that water absorption only marginally affects the penetration depth in human skin at 1550 nm. For several applications this wavelength may be preferred. (© 2009 WILEY-VCH Verlag GmbH \& Co. KGaA, Weinheim)}, year = {2009} } |
Fourier domain mode locked (FDML) lasers for polarization sensitive OCT, in Optical Coherence Tomography and Coherence Techniques IV , Peter E. Andersen and Brett E. Bouma, Eds. SPIE, 072009. pp. 73720M.
DOI: | 10.1117/12.831835 |
Bibtex: | @inproceedings{10.1117/12.831835, author = {Gesa Palte and Wolfgang Wieser and Benjamin R. Biedermann and Christoph M. Eigenwillig and Robert Huber}, title = {{Fourier domain mode locked (FDML) lasers for polarization sensitive OCT}}, volume = {7372}, booktitle = {Optical Coherence Tomography and Coherence Techniques IV}, editor = {Peter E. Andersen and Brett E. Bouma}, organization = {International Society for Optics and Photonics}, publisher = {SPIE}, pages = {73720M}, abstract = {A Fourier Domain mode-locked (FDML) laser for polarization sensitive optical coherence tomography (OCT) is presented. The laser generates an alternating sequence of wavelength sweeps with their polarization states 90° separated on the Poincare sphere.}, keywords = {Lasers, tunable, optical coherence tomography, lasers, imaging systems, polarization, fiber}, year = {2009}, doi = {10.1117/12.831835}, URL = {https://doi.org/10.1117/12.831835} } |
State-of-the-art and future of ultrahigh speed OCT, in CLEO/Europe and EQEC 2009 Conference Digest , Optica Publishing Group, 062009. pp. JTuA_3.
DOI: | 10.1109/CLEOE-EQEC.2009.5191695 |
Bibtex: | @INPROCEEDINGS{5191695, author={Huber, Robert}, booktitle={CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference}, title={State-of-the-art and future of ultrahigh speed OCT}, year={2009}, volume={}, number={}, pages={1-1}, abstract={This paper reviews the current status of high speed OCT systems on the different levels of development: commercial, laboratory prototype style and proof of concept type systems. The pro and contra of SD-OCT and SS-OCT are discussed and an analysis of the desired optimum imaging speeds for various applications. SS-OCT systems are used for imaging in highly scattering tissue ~1300 nm, a line rate of 60 MHz was achieved by with SD-OCT.}, keywords={}, doi={10.1109/CLEOE-EQEC.2009.5191695}, ISSN={}, month={June},} |
Dispersion, coherence and noise of Fourier Domain Mode Locked (FDML) lasers, in CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference , IEEE, 062009. pp. 1-1.
DOI: | 10.1109/CLEOE-EQEC.2009.5192900 |
Bibtex: | @INPROCEEDINGS{5192900, author={Biedermann, Benjamin R. and Wieser, Wolfgang and Eigenwillig, Christoph M. and Klein, Thomas and Huber, Robert}, booktitle={CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference}, title={Dispersion, coherence and noise of Fourier Domain Mode Locked (FDML) lasers}, year={2009}, volume={}, number={}, pages={1-1}, abstract={We present a detailed analysis of coherence and noise of the FDML laser, depending on filter drive frequency, detuning and amount of cavity dispersion. The results provide insight into phase and amplitude noise of the laser light itself. We address the following two questions: (1) How much dispersion compensation is necessary for optimum laser performance in FDML for a certain width of the optical band pass filter? (2) How are timing mismatch effects, caused by either detuning of the drive frequency or chromatic dispersion in the cavity of the filter, related to coherence length and noise?}, keywords={}, doi={10.1109/CLEOE-EQEC.2009.5192900}, ISSN={}, month={June},} |
Dispersion, coherence and noise of Fourier domain mode locked lasers, Opt. Express , vol. 17, no. 12, pp. 9947-9961, 05 2009. Optica Publishing Group.
DOI: | 10.1364/OE.17.009947 |
Bibtex: | @article{Biedermann:09, author = {Benjamin R. Biedermann and Wolfgang Wieser and Christoph M. Eigenwillig and Thomas Klein and Robert Huber}, journal = {Opt. Express}, keywords = {Noise in imaging systems; Optical coherence tomography; Interferometry; Lasers, tunable; Optical coherence tomography; Dispersion; Laser light; Laser modes; Laser operation; Laser sources; Mode locking; Swept lasers}, number = {12}, pages = {9947--9961}, publisher = {Optica Publishing Group}, title = {Dispersion, coherence and noise of Fourier domain mode locked lasers}, volume = {17}, month = {Jun}, year = {2009}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-17-12-9947}, doi = {10.1364/OE.17.009947}, abstract = {We report on the effect of chromatic dispersion on coherence length and noise of Fourier Domain Mode Locked (FDML) lasers. An FDML laser with a sweep range of 100nm around 1550nm has been investigated. Cavity configurations with and without dispersion compensation have been analyzed using different widths of the intra-cavity optical band-pass filter. The measurements are compared to non-FDML wavelength swept laser sources. Based on these observations, a simple model is developed providing a connection between timing, photon cavity lifetime and characteristic time constant of the filter. In an optimized configuration, an instantaneous laser linewidth of 20pm is observed, corresponding to a 10{\texttimes} narrowing compared to the intra-cavity optical band-pass filter. A relative intensity noise of -133dBc/Hz or 0.2\% at 100MHz detection bandwidth during sweep operation is observed. For optimum operation, the filter drive frequency has to be set within 2ppm or 120mHz at 51kHz.}, } |
Subharmonic Fourier domain mode locking, Opt. Lett. , vol. 34, no. 6, pp. 725-727, 03 2009. Optica Publishing Group.
DOI: | 10.1364/OL.34.000725 |
Bibtex: | @article{Eigenwillig:09, author = {Christoph M. Eigenwillig and Wolfgang Wieser and Benjamin R. Biedermann and Robert Huber}, journal = {Opt. Lett.}, keywords = {Coherence imaging; Optical coherence tomography; Three-dimensional image acquisition; Lasers, tunable; Medical and biological imaging; Optical coherence tomography; Fourier domain mode locking; Laser operation; Laser sources; Laser systems; Mode locking; Optical coherence tomography}, number = {6}, pages = {725--727}, publisher = {Optica Publishing Group}, title = {Subharmonic Fourier domain mode locking}, volume = {34}, month = {Mar}, year = {2009}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-34-6-725}, doi = {10.1364/OL.34.000725}, abstract = {We demonstrate a subharmonically Fourier domain mode-locked wavelength-swept laser source with a substantially reduced cavity fiber length. In contrast to a standard Fourier domain mode-locked configuration, light is recirculated repetitively in the delay line with the optical bandpass filter used as switch. The laser has a fundamental optical round trip frequency of 285 kHz and can be operated at integer fractions thereof (subharmonics). Sweep ranges up to 95 nm full width centred at 1317 nm are achieved at the 1/5th subharmonic. A maximum sensitivity of 116 dB and an axial resolution of 12 $\mu$m in air are measured at an average sweep power of 12 mW. A sensitivity roll-off of 11 dB over 4 mm and 25 dB over 10 mm is observed and optical coherence tomography imaging is demonstrated. Besides the advantage of a reduced fiber length, subharmonic Fourier domain mode locking (shFDML) enables simple scaling of the sweep speed by extracting light from the delay part of the resonator. A sweep rate of 570 kHz is achieved. Characteristic features of shFDML operation, such as power leakage during fly-back and cw breakthrough, are investigated.}, } |
Swept source OCT imaging of human anterior segment at 200 kHz, in Ophthalmic Technologies XIX , Fabrice Manns and Per G. Söderberg and Arthur Ho, Eds. SPIE, 022009. pp. 716308.
DOI: | 10.1117/12.808555 |
Bibtex: | @inproceedings{10.1117/12.808555, author = {Karol Karnowski and Michalina Gora and Bartlomiej Kaluzny and Robert Huber and Maciej Szkulmowski and Andrzej Kowalczyk and Maciej Wojtkowski}, title = {{Swept source OCT imaging of human anterior segment at 200 kHz}}, volume = {7163}, booktitle = {Ophthalmic Technologies XIX}, editor = {Fabrice Manns and Per G. S{\"o}derberg and Arthur Ho}, organization = {International Society for Optics and Photonics}, publisher = {SPIE}, pages = {716308}, abstract = {We present applicability of the high speed swept-source optical coherence tomography for in vivo imaging of the anterior segment of the human eye. Three dimensional imaging of the cornea with reduced motion artifacts is possible by using swept source with Fourier domain mode locking operating at 200kHz with 1300nm central wavelength. High imaging speeds allow for assessment of anterior and posterior corneal topography and generation of thickness and elevation maps.}, keywords = {Optical Coherence Tomography, Fourier domain detection methods, swept source OCT, anterior segment of the eye}, year = {2009}, doi = {10.1117/12.808555}, URL = {https://doi.org/10.1117/12.808555} } |
Fourier domain mode locking: new lasers for optical coherence tomography, 02 2009. Online: SPIE.
DOI: | 10.1117/2.1200901.1440 |
Bibtex: | @Misc{HU_2009_Huber_b, Title = {{Fourier domain mode locking: new lasers for optical coherence tomography}}, Author = {Huber, Robert}, Year = {2009}, Booktitle = {SPIE Newsroom}, Doi = {10.1117/2.1200901.1440}, ISSN = {18182259}, keywords = {AG-Huber_FDML, AG-Huber_OCT}, Url = {http://www.spie.org/x33321.xml} } |
2008
Raman-pumped Fourier-domain mode-locked laser: analysis of operation and application for optical coherence tomography, Opt. Lett. , vol. 33, no. 23, pp. 2815-2817, Dec. 2008. Optica Publishing Group.
DOI: | 10.1364/OL.33.002815 |
Bibtex: | @article{Klein:08, author = {Thomas Klein and Wolfgang Wieser and Benjamin R. Biedermann and Christoph M. Eigenwillig and Gesa Palte and Robert Huber}, journal = {Opt. Lett.}, keywords = {Optical coherence tomography; Lasers, fiber; Lasers, Raman; Lasers, tunable; Optical coherence tomography; Laser operation; Mode locking; Optical coherence tomography; Optical components; Raman fiber lasers; Semiconductor lasers}, number = {23}, pages = {2815--2817}, publisher = {Optica Publishing Group}, title = {Raman-pumped Fourier-domain mode-locked laser: analysis of operation and application for optical coherence tomography}, volume = {33}, month = {Dec}, year = {2008}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-33-23-2815}, doi = {10.1364/OL.33.002815}, abstract = {We demonstrate a Raman-pumped Fourier-domain mode-locked (FDML) fiber laser and optical coherence tomography imaging with this source. The wavelength sweep range of only 30 nm centered around 1550 nm results in limited axial resolution, hence a nonbiological sample is imaged. An output power of 1.9 mW was achieved at a sweep rate of 66 kHz and a maximum ranging depth of ~2.5 cm. Roll-off characteristics are found to be similar to FDML lasers with semiconductor optical amplifiers as gain media. The application of Raman gain also enables unperturbed cavity ring-down experiments in FDML lasers for the first time, providing direct access to the photon lifetime in the laser cavity. Good agreement with nonswept cw operation is proof of the stationary operation of FDML lasers.}, } |
Ultrahigh-speed optical coherence tomography for three-dimensional and en face imaging of the retina and optic nerve head., Investigative Ophthalmology & Visual Science , vol. 49, no. 11, pp. 5103-5110, Nov. 2008.
DOI: | 10.1167/iovs.08-2127 |
Bibtex: | @article{10.1167/iovs.08-2127, author = {Srinivasan, Vivek J. and Adler, Desmond C. and Chen, Yueli and Gorczynska, Iwona and Huber, Robert and Duker, Jay S. and Schuman, Joel S. and Fujimoto, James G.}, title = "{Ultrahigh-Speed Optical Coherence Tomography for Three-Dimensional and En Face Imaging of the Retina and Optic Nerve Head}", journal = {Investigative Ophthalmology & Visual Science}, volume = {49}, number = {11}, pages = {5103-5110}, year = {2008}, month = {11}, abstract = "{ purpose. To demonstrate ultrahigh-speed optical coherence tomography (OCT) imaging of the retina and optic nerve head at 249,000 axial scans per second and a wavelength of 1060 nm. To investigate methods for visualization of the retina, choroid, and optic nerve using high-density sampling enabled by improved imaging speed. methods. A swept-source OCT retinal imaging system operating at a speed of 249,000 axial scans per second was developed. Imaging of the retina, choroid, and optic nerve were performed. Display methods such as speckle reduction, slicing along arbitrary planes, en face visualization of reflectance from specific retinal layers, and image compounding were investigated. results. High-definition and three-dimensional (3D) imaging of the normal retina and optic nerve head were performed. Increased light penetration at 1060 nm enabled improved visualization of the choroid, lamina cribrosa, and sclera. OCT fundus images and 3D visualizations were generated with higher pixel density and less motion artifacts than standard spectral/Fourier domain OCT. En face images enabled visualization of the porous structure of the lamina cribrosa, nerve fiber layer, choroid, photoreceptors, RPE, and capillaries of the inner retina. conclusions. Ultrahigh-speed OCT imaging of the retina and optic nerve head at 249,000 axial scans per second is possible. The improvement of ∼5 to 10× in imaging speed over commercial spectral/Fourier domain OCT technology enables higher density raster scan protocols and improved performance of en face visualization methods. The combination of the longer wavelength and ultrahigh imaging speed enables excellent visualization of the choroid, sclera, and lamina cribrosa. }", issn = {1552-5783}, doi = {10.1167/iovs.08-2127}, url = {https://doi.org/10.1167/iovs.08-2127}, eprint = {https://arvojournals.org/arvo/content\_public/journal/iovs/932946/z7g01108005103.pdf}, } |
Real time en face Fourier-domain optical coherence tomography with direct hardware frequency demodulation, Opt. Lett. , vol. 33, no. 21, pp. 2556-2558, Oct. 2008. Optica Publishing Group.
DOI: | 10.1364/OL.33.002556 |
Bibtex: | @article{Biedermann:08, author = {Benjamin R. Biedermann and Wolfgang Wieser and Christoph M. Eigenwillig and Gesa Palte and Desmond C. Adler and Vivek J. Srinivasan and James G. Fujimoto and Robert Huber}, journal = {Opt. Lett.}, keywords = {Coherence imaging; Optical coherence tomography; Three-dimensional image acquisition; Lasers, tunable; Medical and biological imaging; Optical coherence tomography; Analog to digital converters; Interference; Laser sources; Medical imaging; Mode locking; Optical coherence tomography}, number = {21}, pages = {2556--2558}, publisher = {Optica Publishing Group}, title = {Real time en face Fourier-domain optical coherence tomography with direct hardware frequency demodulation}, volume = {33}, month = {Nov}, year = {2008}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-33-21-2556}, doi = {10.1364/OL.33.002556}, abstract = {We demonstrate en face swept source optical coherence tomography (ss-OCT) without requiring a Fourier transformation step. The electronic optical coherence tomography (OCT) interference signal from a k-space linear Fourier domain mode-locked laser is mixed with an adjustable local oscillator, yielding the analytic reflectance signal from one image depth for each frequency sweep of the laser. Furthermore, a method for arbitrarily shaping the spectral intensity profile of the laser is presented, without requiring the step of numerical apodization. In combination, these two techniques enable sampling of the in-phase and quadrature signal with a slow analog-to-digital converter and allow for real-time display of en face projections even for highest axial scan rates. Image data generated with this technique is compared to en face images extracted from a three-dimensional OCT data set. This technique can allow for real-time visualization of arbitrarily oriented en face planes for the purpose of alignment, registration, or operator-guided survey scans while simultaneously maintaining the full capability of high-speed volumetric ss-OCT functionality.}, } |
Jan Philip Kolb
MPM-Histo
Wolfgang Draxinger
AG Huber
Gebäude 81
,
Raum 72
wolfgang.draxinger(at)uni-luebeck.de
+49 451 3101 3229
Madita Göb
AG Huber
Gebäude 81
,
Raum 61
m.goeb(at)uni-luebeck.de
+49 451 3101 3262
Sazgar Burhan
AG Huber
Gebäude 81
,
Raum 61
sa.burhan(at)uni-luebeck.de
+49 451 3101 3263