Optische Kohärenztomographie (OCT)

Anwendung und Entwicklung von ultraschnellen MHz-OCT-Systemen

Die OCT ist ein nichtinvasives Bildgebungsverfahren, welches man typischerweise nutzt um dreidimensionale Tomogramme mit hoher Auflösung (~10µm) von stark streuendem Gewebe zu erstellen. Durch die Verwendung von eigens entwickelten FDML-Lasern erreichen wir Aufnahmegeschwindigkeiten von mehreren Millionen Tiefenscans pro Sekunde (MHz-OCT). Dies ist um ein bis zwei Größenordnungen schneller als derzeitige kommerzielle Systeme.

 

Diese hohen Geschwindigkeiten sind in vielen klinischen Bereichen (z.B. ophthalmisches und intravaskuläres OCT) nützlich, da sie die Aufnahmedauer verringern und helfen Bewegungsartefakte zu vermeiden. Die hohe Geschwindigkeit ermöglicht aber auch einen Zugang zur Phase des detektierten Lichts und damit neue numerische Methoden zur Bildverbesserung und Kontrastgebung in der Swept-Source-OCT.

Unsere Arbeitsgruppe forscht im Bereich der OCT an neuen Technologien und zeigt mögliche Anwendungsgebiete auf.

Forschungsschwerpunkte:

  • MHz-OCT - Ultraschnelle OCT-Bildgebung mit mehreren millionen Tiefenschnitten pro Sekunde
  • LARA-OCT - Großflächige OCT-Bildgebung von Haut mittel Roboter unterstützer MHz-OCT
  • VR-OCT - Echtzeit Berechnung und Visualisierung ganzer OCT-Volumen in einer virtuellen Umgebung
  • Augen OCT - Anwendung der MHz-OCT am Auge zur Darstellung der Netzhaut oder des Augenvordergrunds
  • Phasensensitive OCT - Erweiterung des Informationsgehalts einer OCT-Aufnahme durch hinzufügen eines Phasenkontrastes
  • Multispektrale OCT - Kombination aus RGB- und OCT-Aufnahmen zur verbesserten Darstellung morphologischer Strukturen

zugehörige Publikationen

2006

Laura A. Kranendonk, Joachim W. Walewski, Scott T. Sanders, and Robert Huber,
"Measurements of Gas Temperature in a HCCI Engine Using a Fourier Domain Mode Locking Laser" SAE Technical Paper 2006-01-1366, Apr. 2006.
DOI:10.4271/2006-01-1366
Bibtex: BibTeX
@TechReport{HU_2006_Kranendonk_a,
  Title                    = {{Measurements of Gas Temperature in a HCCI Engine Using a Fourier Domain Mode Locking Laser}},
  Author                   = {Kranendonk, Laura A and Walewski, Joachim W and Sanders, Scott T and Huber, Robert and Fujimoto, James G},
  Year                     = {2006},
  Month                    = apr,
  pages  = {1366 1--5},
  Doi                      = {10.4271/2006-01-1366},
keywords = {AG-Huber_FDML, AG-Huber_OCT},
  Url                      = {http://www.sae.org/technical/papers/2006-01-1366}
}
Kenji Taira, Robert Huber, Maciej Wojtkowski, and James G. Fujimoto,
Fourier domain mode-locked lasers for swept source OCT imaging at up to 290 kHz scan rates, in Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine X , Valery V. Tuchin and Joseph A. Izatt and James G. Fujimoto, Eds. SPIE, Feb.2006. pp. 60790U.
DOI:10.1117/12.648880
Bibtex: BibTeX
@inproceedings{10.1117/12.648880,
author = {R. Huber and K. Taira and M. Wojtkowski and J. G. Fujimoto},
title = {{Fourier domain mode-locked lasers for swept source OCT imaging at up to 290 kHz scan rates}},
volume = {6079},
booktitle = {Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine X},
editor = {Valery V. Tuchin and Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {60790U},
abstract = {A new type of laser operation, Fourier Domain Mode Locking (FDML), is demonstrated for high performance, frequency swept light sources.  FDML achieves superior sweep speeds, coherence lengths and bandwidths compared to standard bulk or fiber lasers.  At 1300 nm a sweep range up to 145 nm, up to 4 cm delay length, and sweep rates up to 290 kHz were achieved.  This light source is demonstrated for swept source OCT imaging.},
keywords = {Fourier Domain Mode Locking, swept laser, tunable laser, wavelength agile, optical coherence tomography, spectral domain, Fourier domain, fiber laser},
year = {2006},
doi = {10.1117/12.648880},
URL = {https://doi.org/10.1117/12.648880}
}
Laura A. Kranendonk, Joachim W. Walewski, Scott T. Sanders, Robert Huber, and James G. Fujimoto,
Measurements of Gas Temperature in an HCCI Engine by Use of a Fourier-Domain Mode-Locking Laser, in Laser Applilcations to Chemical, Security and Environmental Analysis , Optica Publishing Group, Feb.2006. pp. TuB2.
DOI:10.1364/LACSEA.2006.TuB2
Bibtex: BibTeX
@inproceedings{Kranendonk:06,
author = {Laura A. Kranendonk and Joachim W. Walewski and Scott T. Sanders and Robert Huber and James G. Fujimoto},
booktitle = {Laser Applilcations to Chemical, Security and Environmental Analysis},
journal = {Laser Applilcations to Chemical, Security and Environmental Analysis},
keywords = {Lasers and laser optics; Diode lasers; Lasers, tunable; Laser operation; Laser sensors; Lasers; Mode locking; Spontaneous emission; Tunable diode lasers},
pages = {TuB2},
publisher = {Optica Publishing Group},
title = {Measurements of gas temperature in an HCCI engine by use of a Fourier-domain mode-locking laser},
year = {2006},
url = {https://opg.optica.org/abstract.cfm?URI=LACSEA-2006-TuB2},
doi = {10.1364/LACSEA.2006.TuB2},
abstract = {Initial measurements of water vapor temperature by use of a Fourier-domain mode-locking laser were performed in a homogenous charge compression ignition engine. We assessed the potential of this FDML laser in combustion applications.},
}

2005

Robert Huber, Maciej Wojtkowski, James G. Fujimoto, James Jiang, and Alex E. Cable,
Three-dimensional and C-mode OCT imaging with a compact, frequency swept laser source at 1300 nm, Opt. Express , vol. 13, no. 26, pp. 10523-10538, Dez. 2005. Optica Publishing Group.
DOI:10.1364/OPEX.13.010523
Bibtex: BibTeX
@article{Huber:05,
author = {R. Huber and M. Wojtkowski and J. G. Fujimoto and J. Y. Jiang and A. E. Cable},
journal = {Opt. Express},
keywords = {Optical coherence tomography; Lasers, tunable; High speed imaging; Image fusion; Laser sources; Semiconductor lasers; Swept lasers; Three dimensional imaging},
number = {26},
pages = {10523--10538},
publisher = {Optica Publishing Group},
title = {Three-dimensional and C-mode OCT imaging with a compact, frequency swept laser source at 1300 nm},
volume = {13},
month = {Dec},
year = {2005},
url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-13-26-10523},
doi = {10.1364/OPEX.13.010523},
abstract = {We demonstrate high resolution, three-dimensional OCT imaging with a high speed, frequency swept 1300 nm laser source. A new external cavity semiconductor laser design, optimized for application to swept source OCT, is discussed. The design of the laser enables adjustment of an internal spectral filter to change the filter bandwidth and provides a robust bulk optics design. The laser generates ~30 mW instantaneous peak power at an effective 16 kHz sweep rate with a tuning range of ~133 nm full width. In frequency domain reflectometry and OCT applications, 109 dB sensitivity and ~10 $\mu$m axial resolution in tissue can be achieved with the swept laser. The high imaging speeds enable three-dimensional OCT imaging, including zone focusing or C-mode imaging and image fusion to acquire large depth of field data sets with high resolution. In addition, three-dimensional OCT data provides coherence gated en face images similar to optical coherence microscopy (OCM) and also enables the generation of images similar to confocal microscopy by summing signals in the axial direction. High speed, three-dimensional OCT imaging can provide comprehensive data which combines the advantages of optical coherence tomography and microscopy in a single system.},
}
Robert Huber, Kenji Taira, Maciej Wojtkowski, and James G. Fujimoto,
Fourier domain mode locked lasers for OCT imaging at up to 290 kHz sweep rates, in Optical Coherence Tomography and Coherence Techniques II , Wolfgang Drexler, Eds. SPIE, Okt.2005. pp. 58611B.
DOI:10.1117/12.641732
Bibtex: BibTeX
@inproceedings{10.1117/12.641732,
author = {R. Huber and K. Taira and M. Wojtkowski and J. G. Fujimoto},
title = {{Fourier domain mode locked lasers for OCT imaging at up to 290 kHz sweep rates}},
volume = {5861},
booktitle = {Optical Coherence Tomography and Coherence Techniques II},
editor = {Wolfgang Drexler},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {58611B},
abstract = {A high speed, tunable laser using Fourier Domain Mode Locking is demonstrated for OCT imaging.  Record sweep speeds up to 290 kHz, 3 cm coherence length and 145 nm range at 1300 nm are achieved.},
keywords = {Fourier domain mode locking, swept source, swept laser, tunable laser, wavelength agile laser, optical coherence tomography, spectral OCT, Fourier domain},
year = {2005},
doi = {10.1117/12.641732},
URL = {https://doi.org/10.1117/12.641732}
}
Robert Huber, Kenji Taira, and James G. Fujimoto,
Fourier Domain Mode Locking: Overcoming limitations of frequency swept light sources and pulsed lasers, in Conference on Lasers and Electro-Optics Europe/ European Quantum Electronics Conference (CLEO/Europe - EQEC 2005) , Mai2005. pp. CP3-5-THU.
Bibtex: BibTeX
@InProceedings{HU_2005_Huber_a,
  Title                    = {{Fourier Domain Mode Locking: Overcoming limitations of frequency swept light sources and pulsed lasers}},
  Author                   = {Huber, Robert A and Taira, Kenji and Fujimoto, James G},
  Booktitle                = {Conference on Lasers and Electro-Optics Europe/ European Quantum Electronics Conference (CLEO/Europe - EQEC 2005)},
keywords = {AG-Huber_FDML, AG-Huber_OCT},
  Year                     = { 2005}
}
Robert Huber, Kenji Taira, Tony H. Ko, Maciej Wojtkowski, Vivek J. Srinivasan, James G. Fujimoto, and Kevin Hsu,
High-Speed, Amplified, Frequency Swept Laser at 20 kHz Sweep Rates for OCT Imaging - Technical Digest (CD), in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science and Photonic Applications Systems Technologies , Optica Publishing Group, Mai2005. pp. JThE33.
DOI:10.1109/QELS.2005.1549239
Bibtex: BibTeX
@inproceedings{Huber:05,
author = {R. Huber and K. Taira and T. H. Ko and M. Wojtkowski and V. Srinivasan and J. G. Fujimoto and K. Hsu},
booktitle = {Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science and Photonic Applications Systems Technologies},
journal = {Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science and Photonic Applications Systems Technologies},
keywords = {Imaging systems; Optical coherence tomography; Lasers and laser optics; Lasers, tunable; Laser amplifiers; Laser sources; Light sources; Optical coherence tomography; Point spread function; Ring lasers},
pages = {JThE33},
publisher = {Optica Publishing Group},
title = {High-speed, amplified, frequency swept laser at 20 kHz sweep rates for OCT imaging},
year = {2005},
url = {https://opg.optica.org/abstract.cfm?URI=QELS-2005-JThE33},
abstract = {We demonstrate a high-speed, frequency swept, 1300 nm laser for Fourier domain OCT. The laser generates ~45 mW instantaneous power with 20 kHz sweep rates and achieves 108 dB sensitivity and 12.7 um resolution.},
}
Robert Huber, Maciej Wojtkowski, Kenji Taira, James G. Fujimoto, and Kevin Hsu,
Amplified, frequency swept lasers for frequency domain reflectometry and OCT imaging: design and scaling principles, Opt. Express , vol. 13, no. 9, pp. 3513-3528, Mai 2005. Optica Publishing Group.
DOI:10.1364/OPEX.13.003513
Bibtex: BibTeX
@article{Huber:05,
author = {R. Huber and M. Wojtkowski and K. Taira and J. G. Fujimoto and K. Hsu},
journal = {Opt. Express},
keywords = {Optical coherence tomography; Lasers, tunable; Fiber lasers; Fiber optic amplifiers; Fiber optic components; Laser sources; Light sources; Tunable diode lasers},
number = {9},
pages = {3513--3528},
publisher = {Optica Publishing Group},
title = {Amplified, frequency swept lasers for frequency domain reflectometry and OCT imaging: design and scaling principles},
volume = {13},
month = {May},
year = {2005},
url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-13-9-3513},
doi = {10.1364/OPEX.13.003513},
abstract = {We demonstrate a high-speed, frequency swept, 1300 nm laser source for frequency domain reflectometry and OCT with Fourier domain/swept-source detection. The laser uses a fiber coupled, semiconductor amplifier and a tunable fiber Fabry-Perot filter. We present scaling principles which predict the maximum frequency sweep speed and trade offs in output power, noise and instantaneous linewidth performance. The use of an amplification stage for increasing output power and for spectral shaping is discussed in detail. The laser generates ~45 mW instantaneous peak power at 20 kHz sweep rates with a tuning range of ~120 nm full width. In frequency domain reflectometry and OCT applications the frequency swept laser achieves 108 dB sensitivity and ~10 {\textmu}m axial resolution in tissue. We also present a fast algorithm for real time calibration of the fringe signal to equally spaced sampling in frequency for high speed OCT image preview.},
}
Robert Huber, Kenji Taira, Maciej Wojtkowski, Tony H. Ko, James G. Fujimoto, and Kevin Hsu,
Figh-speed frequency swept light source for Fourier domain OCT at 20 kHz A-scan rate, in Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine IX , Valery V. Tuchin and Joseph A. Izatt and James G. Fujimoto, Eds. SPIE, Apr.2005. pp. 96-100.
DOI:10.1117/12.592552
Bibtex: BibTeX
@inproceedings{10.1117/12.592552,
author = {Robert Huber and Kenji Taira and Maciej Wojtkowski and Tony Hong-Tyng Ko and James G. Fujimoto and Kevin Hsu},
title = {{High-speed-frequency swept light source for Fourier domain OCT at 20-kHz A-scan rate}},
volume = {5690},
booktitle = {Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine IX},
editor = {Valery V. Tuchin and Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {96 -- 100},
abstract = {We demonstrate a high-speed tunable, continuous wave laser source for Fourier domain OCT.  The laser source is based on a fiber coupled, semiconductor optical amplifier and a tunable ultrahigh finesse, fiber Fabry Perot filter for frequency tuning.  The light source provides frequency scan rates of up to 20,000 sweeps per second over a wavelength range of >70 nm FWHM at 1330 nm, yielding an axial resolution of ~14 μm in air.  The linewidth is narrow and corresponds to a coherence length of several mm, enabling OCT imaging over a large axial range.},
keywords = {swept source, Fourier Domain, OCT, tunable laser, Spectral Domain, frequency domain imaging, OFDI, sweep},
year = {2005},
doi = {10.1117/12.592552},
URL = {https://doi.org/10.1117/12.592552}
}