The research group led by Robert Huber conducts research in the fields of optical coherence tomography (OCT), non-linear imaging and laser physics. Here, work is mainly done on novel pico second lasers and on Fourier domain mode-locked (FDML) lasers. This laser concept was developed by Robert Huber and enables the realization of particularly fast tunable laser light sources. The research focus here is on further technological development, understanding of the physical processes and also on the implementation of FDML lasers for OCT applications. Besides OCT, FDML lasers are also used for nonlinear imaging and spectroscopy.
Another focus is on optical coherence tomography with tunable light sources (swept source OCT, SS-OCT). Here, among other applications, the in-house developed FDML lasers are used for ultrafast imaging to generate cross-sectional images of biological tissues such as skin or eye. Due to the high tuning rate, applications like VR-OCT, which displays entire volumes in a virtual environment with real-time video repetition rates, are possible.
With non-linear optical imaging, the group is pursuing further imaging techniques. Research areas are in time-encoded (TICO) Raman spectroscopy and microscopy, two-photon fluorescence microscopy (TPEF), and two-photon single-pulse fluorescence lifetime imaging (SP-FLIM). These techniques use novel pico second lasers that are also being researched and developed in the group.
Our main research topics:
- Fourier Domain Mode Locked (FDML) lasers - laser physics, technology and application.
- Optical Coherence Tomography (OCT) - applications of MHz-OCT on skin and eye
- Non-linear microscopy and spectroscopy
- Pico second lasers
Publications
2008
Photothermal detection of gold nanoparticles using phase-sensitive optical coherence tomography, Opt. Express , vol. 16, no. 7, pp. 4376-4393, 03 2008. Optica Publishing Group.
DOI: | 10.1364/OE.16.004376 |
Bibtex: | @article{Adler:08, author = {Desmond C. Adler and Shu-Wei Huang and Robert Huber and James G. Fujimoto}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Phase measurement; Lasers, tunable; Nanomaterials; Laser beams; Medical imaging; Multimode lasers; Optical Doppler tomography; Phase modulation; Single mode lasers}, number = {7}, pages = {4376--4393}, publisher = {Optica Publishing Group}, title = {Photothermal detection of gold nanoparticles using phase-sensitive optical coherence tomography}, volume = {16}, month = {Mar}, year = {2008}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-16-7-4376}, doi = {10.1364/OE.16.004376}, abstract = {The detection of a gold nanoparticle contrast agent is demonstrated using a photothermal modulation technique and phase sensitive optical coherence tomography (OCT). A focused beam from a laser diode at 808 nm is modulated at frequencies of 500 Hz--60 kHz while irradiating a solution containing nanoshells. Because the nanoshells are designed to have a high absorption coefficient at 808 nm, the laser beam induces small-scale localized temperature oscillations at the modulation frequency. These temperature oscillations result in optical path length changes that are detected by a phase-sensitive, swept source OCT system. The OCT system uses a double-buffered Fourier domain mode locked (FDML) laser operating at a center wavelength of 1315 nm and a sweep rate of 240 kHz. High contrast is observed between phantoms containing nanoshells and phantoms without nanoshells. This technique represents a new method for detecting gold nanoparticle contrast agents with excellent signal-to-noise performance at high speeds using OCT.}, } |
2007
Three-dimensional endomicroscopy using optical coherence tomography, Nature Photonics , vol. 1, no. 12, pp. 709-716, Nov. 2007.
DOI: | 10.1038/nphoton.2007.228 |
Bibtex: | @article{HU_2007_Adlera, Title = {Three-dimensional endomicroscopy using optical coherence tomography}, Author = {Adler, Desmond C. and Chen, Yu and Huber, Robert and Schmitt, Joseph and Connolly, James and Fujimoto, James G.}, Journal = {Nature Photonics}, Year = {2007}, Month = nov, Number = {12}, Pages = {709--716}, Volume = {1}, Doi = {10.1038/nphoton.2007.228}, Timestamp = {2014.11.20}, ISSN = {1749-4885} } |
Comparison of three-dimensional optical coherence tomography and high resolution photography for art conservation studies, Opt. Express , vol. 15, no. 24, pp. 15972-15986, Nov. 2007. Optica Publishing Group.
DOI: | 10.1364/OE.15.015972 |
Bibtex: | @article{Adler:07, author = {Desmond C. Adler and Jens Stenger and Iwona Gorczynska and Henry Lie and Teri Hensick and Ron Spronk and Stephan Wolohojian and Narayan Khandekar and James Y. Jiang and Scott Barry and Alex E. Cable and Robert Huber and James G. Fujimoto}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Photography; Three-dimensional image acquisition; Optical inspection; Lasers, tunable; Three-dimensional microscopy; Digital photography; Fourier domain mode locking; Image processing; Speckle interferometry; Three dimensional imaging; Three dimensional measurement}, number = {24}, pages = {15972--15986}, publisher = {Optica Publishing Group}, title = {Comparison of three-dimensional optical coherence tomography and high resolution photography for art conservation studies}, volume = {15}, month = {Nov}, year = {2007}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-15-24-15972}, doi = {10.1364/OE.15.015972}, abstract = {Gold punchwork and underdrawing in Renaissance panel paintings are analyzed using both three-dimensional swept source/Fourier domain optical coherence tomography (3D-OCT) and high resolution digital photography. 3D-OCT can generate en face images with micrometer-scale resolutions at arbitrary sectioning depths, rejecting out-of-plane light by coherence gating. Therefore 3D-OCT is well suited for analyzing artwork where a surface layer obscures details of interest. 3D-OCT also enables cross-sectional imaging and quantitative measurement of 3D features such as punch depth, which is beneficial for analyzing the tools and techniques used to create works of art. High volumetric imaging speeds are enabled by the use of a Fourier domain mode locked (FDML) laser as the 3D-OCT light source. High resolution infrared (IR) digital photography is shown to be particularly useful for the analysis of underdrawing, where the materials used for the underdrawing and paint layers have significantly different IR absorption properties. In general, 3D-OCT provides a more flexible and comprehensive analysis of artwork than high resolution photography, but also requires more complex instrumentation and data analysis.}, } |
High speed engine gas thermometry by Fourier-domain mode-locked laser absorption spectroscopy, Opt. Express , vol. 15, no. 23, pp. 15115-15128, Nov. 2007. Optica Publishing Group.
DOI: | 10.1364/OE.15.015115 |
Bibtex: | @article{Kranendonk:07, author = {Laura A. Kranendonk and Xinliang An and Andrew W. Caswell and Randy E. Herold and Scott T. Sanders and Robert Huber and James G. Fujimoto and Yasuhiro Okura and Yasuhiro Urata}, journal = {Opt. Express}, keywords = {Spectrometers and spectroscopic instrumentation; Lasers, tunable; Spectroscopy, fluorescence and luminescence; Absorption; Spectroscopy, diode lasers; Spectroscopy, infrared; Fourier transform spectroscopy; Laser modes; Laser sources; Laser spectroscopy; Molecular spectra; Optical coherence tomography}, number = {23}, pages = {15115--15128}, publisher = {Optica Publishing Group}, title = {High speed engine gas thermometry by Fourier-domain mode-locked laser absorption spectroscopy}, volume = {15}, month = {Nov}, year = {2007}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-15-23-15115}, doi = {10.1364/OE.15.015115}, abstract = {We present a novel method for low noise, high-speed, real-time spectroscopy to monitor molecular absorption spectra. The system is based on a rapidly swept, narrowband CW Fourier-domain mode-locked (FDML) laser source for spectral encoding in time and an optically time-multiplexed split-pulse data acquisition system for improved noise performance and sensitivity. An acquisition speed of $\sim$100 kHz, a spectral resolution better than 0.1 nm over a wavelength range of $\sim$1335--1373 nm and a relative noise level of $\sim$5 mOD ($\sim$1\% minimum detectable base-e absorbance) are achieved. The system is applied for crank-angle-resolved gas thermometry by H2O absorption spectroscopy in an engine motoring at 600 and 900 rpm with a precision of $\sim$1\%. Influences of various noise sources such as laser phase and intensity noise, trigger and synchronization jitter in the electronic detection system, and the accuracy of available H2O absorption databases are discussed.}, } |
Fourier domain mode locking at 1050 nm for ultra-high-speed optical coherence tomography of the human retina at 236,000 axial scans per second, Opt. Lett. , vol. 32, no. 14, pp. 2049-2051, 07 2007. Optica Publishing Group.
DOI: | 10.1364/OL.32.002049 |
Bibtex: | @article{Huber:07, author = {R. Huber and D. C. Adler and V. J. Srinivasan and J. G. Fujimoto}, journal = {Opt. Lett.}, keywords = {Optical coherence tomography; Lasers, tunable; Medical and biological imaging; Amplified spontaneous emission; Fourier domain mode locking; Image quality; Optical coherence tomography; Retina; Retina scanning}, number = {14}, pages = {2049--2051}, publisher = {Optica Publishing Group}, title = {Fourier domain mode locking at 1050 nm for ultra-high-speed optical coherence tomography of the human retina at 236,000 axial scans per second}, volume = {32}, month = {Jul}, year = {2007}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-32-14-2049}, doi = {10.1364/OL.32.002049}, abstract = {A Fourier domain mode-locked (FDML) laser at 1050 nm for ultra-high-speed optical coherence tomography (OCT) imaging of the human retina is demonstrated. Achievable performance, physical limitations, design rules, and scaling principles for FDML operation and component choice in this wavelength range are discussed. The fiber-based FDML laser operates at a sweep rate of 236 kHz over a 63 nm tuning range, with 7 mW average output power. Ultra-high-speed retinal imaging is demonstrated at 236,000 axial scans per second. This represents a speed improvement of ~10{\texttimes} over typical high-speed OCT systems, paving the way for densely sampled volumetric data sets and new imaging protocols.}, } |
Fourier Domain Mode Locking (FDML) in the non-zero dispersion regime: A laser for ultrahigh-speed retinal OCT imaging at 236kHz line rate, in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies , Optica Publishing Group, 052007. pp. CThAA5.
DOI: | 10.1109/CLEO.2007.4452681} |
Bibtex: | @inproceedings{Huber:07, author = {Robert Huber and Vivek J. Srinivasan and Desmond C. Adler and I. Gorczynska and James G. Fujimoto}, booktitle = {Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies}, journal = {Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies}, keywords = {General physics; General science; Fourier domain mode locking; Image quality; In vivo imaging; Laser sources; Ophthalmic imaging; Optical coherence tomography}, pages = {CThAA5}, publisher = {Optica Publishing Group}, title = {Fourier Domain Mode Locking (FDML) in the non-zero dispersion regime: A laser for ultrahigh-speed retinal OCT imaging at 236kHz line rate}, year = {2007}, url = {https://opg.optica.org/abstract.cfm?URI=CLEO-2007-CThAA5}, abstract = {Fourier Domain Mode Locking (FDML) in the 1070nm wavelength range is investigated. Problems, design rules and the performance of an FDML laser with a dispersive cavity are discussed. Retinal OCT imaging at 236kHz is demonstrated.}, } |
Optical coherence tomography phase microscopy using buffered fourier domain mode locked (FDML) lasers at up to 370,000 lines per second, in 2007 Conference on Lasers and Electro-Optics (CLEO) , IEEE, 052007. pp. 1-2.
DOI: | 10.1109/CLEO.2007.4452406 |
Bibtex: | @INPROCEEDINGS{4452406, author={Adler, Desmond C. and Huber, Robert and Fujimoto, James G.}, booktitle={2007 Conference on Lasers and Electro-Optics (CLEO)}, title={Optical Coherence Tomography Phase Microscopy Using Buffered Fourier Domain Mode Locked (FDML) Lasers at up to 370,000 Lines per Second}, year={2007}, volume={}, number={}, pages={1-2}, abstract={Buffered FDML lasers are applied for phase-sensitive sub-nanometer OCT phase microscopy and dynamic surface displacement measurements at speeds up to 370,000 axial lines per second. Excellent phase stability is demonstrated at high speeds.}, keywords={}, doi={10.1109/CLEO.2007.4452406}, ISSN={2160-9004}, month={May},} |
Ultrahigh-speed optical coherence tomography imaging and visualization of the embryonic avian heart using a buffered Fourier Domain Mode Locked laser, Opt. Express , vol. 15, no. 10, pp. 6251-6267, 05 2007. Optica Publishing Group.
DOI: | 10.1364/OE.15.006251 |
Bibtex: | @article{Jenkins:07, author = {M. W. Jenkins and D. C. Adler and M. Gargesha and R. Huber and F. Rothenberg and J. Belding and M. Watanabe and D. L. Wilson and J. G. Fujimoto and A. M. Rollins}, journal = {Opt. Express}, keywords = {Three-dimensional image processing; Lasers; Medical and biological imaging; Optical coherence tomography; Developmental biology; Gated imaging; Imaging systems; Laser Doppler velocimetry; Laser modes; Mode locking}, number = {10}, pages = {6251--6267}, publisher = {Optica Publishing Group}, title = {Ultrahigh-speed optical coherence tomography imaging and visualization of the embryonic avian heart using a buffered Fourier Domain Mode Locked laser}, volume = {15}, month = {May}, year = {2007}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-15-10-6251}, doi = {10.1364/OE.15.006251}, abstract = {The embryonic avian heart is an important model for studying cardiac developmental biology. The mechanisms that govern the development of a four-chambered heart from a peristaltic heart tube are largely unknown due in part to a lack of adequate imaging technology. Due to the small size and rapid motion of the living embryonic avian heart, an imaging system with high spatial and temporal resolution is required to study these models. Here, an optical coherence tomography (OCT) system using a buffered Fourier Domain Mode Locked (FDML) laser is applied for ultrahigh-speed non-invasive imaging of embryonic quail hearts at 100,000 axial scans per second. The high scan rate enables the acquisition of high temporal resolution 2D datasets (195 frames per second or 5.12 ms between frames) and 3D datasets (10 volumes per second). Spatio-temporal details of cardiac motion not resolvable using previous OCT technology are analyzed. Visualization and measurement techniques are developed to non-invasively observe and quantify cardiac motion throughout the brief period of systole (less than 50 msec) and diastole. This marks the first time that the preseptated embryonic avian heart has been imaged in 4D without the aid of gating and the first time it has been viewed in cross section during looping with extremely high temporal resolution, enabling the observation of morphological dynamics of the beating heart during systole.}, } |
Swept source optical coherence microscopy using a Fourier domain mode-locked laser, Opt. Express , vol. 15, no. 10, pp. 6210-6217, 05 2007. Optica Publishing Group.
DOI: | 10.1364/OE.15.006210 |
Bibtex: | @article{Huang:07, author = {Shu-Wei Huang and Aaron D. Aguirre and Robert A. Huber and Desmond C. Adler and James G. Fujimoto}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Lasers, tunable; Medical and biological imaging; Confocal microscopy; Three-dimensional microscopy; Image quality; Laser sources; Mode locking; Optical delay lines; Swept sources; Three dimensional imaging}, number = {10}, pages = {6210--6217}, publisher = {Optica Publishing Group}, title = {Swept source optical coherence microscopy using a Fourier domain mode-locked laser}, volume = {15}, month = {May}, year = {2007}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-15-10-6210}, doi = {10.1364/OE.15.006210}, abstract = {Swept source optical coherence microscopy (OCM) enables cellular resolution en face imaging as well as integration with optical coherence tomography (OCT) cross sectional imaging. A buffered Fourier domain mode-locked (FDML) laser light source provides high speed, three dimensional imaging. Image resolutions of 1.6 $\mu$m {\texttimes} 8 $\mu$m (transverse {\texttimes} axial) with a 220 $\mu$m {\texttimes} 220 $\mu$m field of view and sensitivity higher than 98 dB are achieved. Three dimensional cellular imaging is demonstrated in vivo in the Xenopus laevis tadpole and ex vivo in the rat kidney and human colon.}, } |
Phase-sensitive optical coherence tomography at up to 370,000 lines per second using buffered Fourier domain mode-locked lasers, Opt. Lett. , vol. 32, no. 6, pp. 626-628, 03 2007. Optica Publishing Group.
DOI: | 10.1364/OL.32.000626 |
Bibtex: | @article{Adler:07, author = {Desmond C. Adler and Robert Huber and James G. Fujimoto}, journal = {Opt. Lett.}, keywords = {Optical coherence tomography; Phase measurement; Lasers, tunable; Amplified spontaneous emission; Laser sources; Mode locking; Optical coherence tomography; Phase measurement; Swept lasers}, number = {6}, pages = {626--628}, publisher = {Optica Publishing Group}, title = {Phase-sensitive optical coherence tomography at up to 370,000 lines per second using buffered Fourier domain mode-locked lasers}, volume = {32}, month = {Mar}, year = {2007}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-32-6-626}, doi = {10.1364/OL.32.000626}, abstract = {Buffered Fourier domain mode-locked (FDML) lasers are demonstrated for dynamic phase-sensitive optical coherence tomography (OCT) and 3D OCT phase microscopy. Systems are operated at sweep speeds of 42, 117, and 370 kHz, and displacement sensitivities of 39, 52, and 102 pm are achieved, respectively. Sensitivities are comparable to spectrometer-based OCT phase microscopy systems, but much faster acquisition speeds are possible. An additional factor of sqrt 2 improvement in noise performance is observed for differential phase measurements, which is important for Doppler OCT. Dynamic measurements of piezoelectric transducer motion and static 3D OCT phase microscopy are demonstrated. Buffered FDML lasers provide excellent displacement sensitivities at extremely high sweep speeds.}, } |
Fourier domain mode-locked (FDML) lasers at 1050 nm and 202,000 sweeps per second for OCT retinal imaging, in Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine XI , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, 022007. pp. 642907.
DOI: | 10.1117/12.704084 |
Bibtex: | @inproceedings{10.1117/12.704084, author = {Robert A. Huber and Desmond C. Adler and Vivek J. Srinivasan and Iwona M Gorczynska and James G. Fujimoto}, title = {{Fourier domain mode-locked (FDML) lasers at 1050 nm and 202,000 sweeps per second for OCT retinal imaging}}, volume = {6429}, booktitle = {Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine XI}, editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin}, organization = {International Society for Optics and Photonics}, publisher = {SPIE}, pages = {642907}, abstract = {Retinal imaging ranks amongst the most important clinical applications for optical coherence tomography (OCT) [1, 2]. The recent demonstration of increased sensitivity [3-6] in Fourier Domain detection [7, 8] has opened the way for dramatically higher imaging speeds, up to axial scan rates of several tens of kilohertz. However, these imaging speeds are still not sufficient for high density 3D datasets and a further increase to several hundreds of kilohertz is necessary. In this paper we demonstrate a swept laser source at 1050 nm with a sweep rate of 202 kHz. The laser source provides ~10 mW average output power, up to 60 nm total sweep range and a sensitivity roll off of less than 10 dB over 4 mm. In vivo 2D and 3D imaging of the human retina at a record axial scan rate of 101 kHz is demonstrated. These results suggest that swept source OCT has the potential to significantly outperform spectral/Fourier domain OCT for ophthalmic imaging applications in the future.}, keywords = {tunable laser, optical coherence tomography, Fourier domain mode locking, swept source, OCT, FDML, retinal imaging, ophthalmic imaging}, year = {2007}, doi = {10.1117/12.704084}, URL = {https://doi.org/10.1117/12.704084} } |
Phase-sensitive optical coherence tomography using buffered Fourier domain mode-locked lasers at up to 370,000 scans per second, in Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine XI , James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin, Eds. SPIE, 022007. pp. 64291L.
DOI: | 10.1117/12.704128 |
Bibtex: | @inproceedings{10.1117/12.704128, author = {Desmond C. Adler and Robert Huber and James G. Fujimoto}, title = {{Phase-sensitive optical coherence tomography using buffered Fourier domain mode-locked lasers at up to 370,000 scans per second}}, volume = {6429}, booktitle = {Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine XI}, editor = {James G. Fujimoto and Joseph A. Izatt and Valery V. Tuchin}, organization = {International Society for Optics and Photonics}, publisher = {SPIE}, pages = {64291L}, abstract = {Phase sensitive optical coherence tomography (OCT) can be used to obtain sub-nanometer displacement measurements of biological and non-biological samples. This technique has many applications, including detection of small amplitude surface motion, and high axial resolution OCT phase microscopy. Doppler OCT is another type of phase sensitive imaging, where differential phase measurements are used to detect fluid flow in biological specimens. For all types of phase sensitive OCT, a light source with low phase noise is required in order to provide good displacement sensitivity. High speed imaging is also necessary in order to minimize motion artifacts and enable the detection of fast transient events. In this manuscript, buffered Fourier Domain Mode Locked (FDML) lasers are demonstrated for ultrahigh-speed phase sensitive OCT detection. The lasers are operated at sweep speeds of 42, 117, and 370 kHz, and displacement sensitivities of 39, 52, and 102 pm are achieved, respectively. These displacement sensitivities are comparable to spectrometer-based phase sensitive OCT systems, but acquisition speeds 1.4 - 13x faster are possible using buffered FDML lasers. An additional factor of √2 improvement in noise performance is observed for differential phase measurements, which has important implications for Doppler OCT. Dynamic measurements of rapid, small-amplitude piezoelectric transducer motion are demonstrated. In general, buffered FDML lasers provide excellent displacement sensitivities at extremely high sweep speeds for phase sensitive OCT measurements.}, keywords = {optical coherence tomography, OCT, optical coherence phase microscopy, swept source phase microscopy, doppler optical coherence tomography, frequency swept lasers, Fourier Domain Mode Locked lasers, FDML}, year = {2007}, doi = {10.1117/12.704128}, URL = {https://doi.org/10.1117/12.704128} } |
High-speed, high-resolution optical coherence tomography retinal imaging with a frequency-swept laser at 850 nm, Opt. Lett. , vol. 32, no. 4, pp. 361-363, 02 2007. Optica Publishing Group.
DOI: | 10.1364/OL.32.000361 |
Bibtex: | @article{Srinivasan:07, author = {V. J. Srinivasan and R. Huber and I. Gorczynska and J. G. Fujimoto and J. Y. Jiang and P. Reisen and A. E. Cable}, journal = {Opt. Lett.}, keywords = {Optical coherence tomography; Lasers, tunable; Medical and biological imaging; Optical coherence tomography; Retina scanning; Semiconductor lasers; Semiconductor optical amplifiers; Spontaneous emission; Tunable lasers}, number = {4}, pages = {361--363}, publisher = {Optica Publishing Group}, title = {High-speed, high-resolution optical coherence tomography retinal imaging with a frequency-swept laser at 850 nm}, volume = {32}, month = {Feb}, year = {2007}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-32-4-361}, doi = {10.1364/OL.32.000361}, abstract = {High-speed, high-resolution optical coherence tomography (OCT) imaging of the human retina is demonstrated using a frequency-swept laser at 850 nm. A compact external cavity semiconductor laser design, optimized for swept-source ophthalmic OCT, is described. The laser enables an effective 16 kHz sweep rate with \>10 mm coherence length and a tuning range of $\sim$35 nm full width at half-maximum, yielding an axial resolution of \<7 $\mu$m in tissue.}, } |
Wavelength-agile H2O absorption spectrometer for thermometry of general combustion gases, Proceedings of the Combustion Institute , vol. 31, no. 1, pp. 783-790, 01 2007.
DOI: | 10.1016/j.proci.2006.08.003 |
Bibtex: | @article{KRANENDONK2007783, title = {Wavelength-agile H2O absorption spectrometer for thermometry of general combustion gases}, journal = {Proceedings of the Combustion Institute}, volume = {31}, number = {1}, pages = {783-790}, year = {2007}, issn = {1540-7489}, doi = {https://doi.org/10.1016/j.proci.2006.08.003}, url = {https://www.sciencedirect.com/science/article/pii/S1540748906002665}, author = {Laura A. Kranendonk and Robert Huber and James G. Fujimoto and Scott T. Sanders}, keywords = {Thermometry, Wavelength-agile, Absorption spectroscopy}, abstract = {Using a novel Fourier-domain mode-locking (FDML) laser scanning 1330–1380nm, we have developed a gas thermometer based on absorption spectroscopy that is appropriate for combustion gases at essentially arbitrary conditions. The path-integrated measurements are particularly useful in homogeneous environments, and here we present measurements in a controlled piston engine and a shock tube. Engine measurements demonstrate a RMS temperature precision of ±3% at 1500K and 200kHz bandwidth; the precision is improved dramatically by averaging. Initial shock tube measurements place the absolute accuracy of the thermometer within ∼2% to 1000K. The sensor performs best when significant H2O vapor is present, but requires only XH2OL>0.07cm at 300K, XH2OL>0.25cm at 1000K, or XH2OL>1.25cm at 3000K for 2% accurate thermometry, assuming a 4kHz measurement bandwidth (200kHz scans with 50 averages). The sensor also provides H2O mole fraction and shows potential for monitoring gas pressure based on the broadening of spectral features. To aid in designing other sensors based on high-temperature, high-pressure H2O absorption spectroscopy, a database of measured spectra is included.} } |
2006
Buffered Fourier domain mode locking: unidirectional swept laser sources for optical coherence tomography imaging at 370,000 lines/s, Opt. Lett. , vol. 31, no. 20, pp. 2975-2977, Oct. 2006. Optica Publishing Group.
DOI: | 10.1364/OL.31.002975 |
Bibtex: | @article{Huber:06, author = {Robert Huber and Desmond C. Adler and James G. Fujimoto}, journal = {Opt. Lett.}, keywords = {Optical coherence tomography; Lasers, tunable; Amplified spontaneous emission; Fourier domain mode locking; Image quality; Laser sources; Optical coherence tomography; Swept sources}, number = {20}, pages = {2975--2977}, publisher = {Optica Publishing Group}, title = {Buffered Fourier domain mode locking: unidirectional swept laser sources for optical coherence tomography imaging at 370,000 lines/s}, volume = {31}, month = {Oct}, year = {2006}, url = {https://opg.optica.org/ol/abstract.cfm?URI=ol-31-20-2975}, doi = {10.1364/OL.31.002975}, abstract = {We describe buffered Fourier domain mode locking (FDML), a technique for tailoring the output and multiplying the sweep rate of FDML lasers. Buffered FDML can be used to create unidirectional wavelength sweeps from the normal bidirectional sweeps in an FDML laser without sacrificing sweep rate. We also investigate the role of the laser source in dynamic range versus sensitivity performance in optical coherence tomography (OCT) imaging. Unidirectional sweep rates of 370 kHz over a 100 nm range at a center wavelength of 1300 nm are achieved. High-speed, swept-source OCT is demonstrated at record speeds of up to 370,000 axial scans per second.}, } |
First steps of retinal photoisomerization in proteorhodopsin, Biophysical Journal , vol. 91, no. 1, pp. 255-262, 07 2006.
DOI: | 10.1529/biophysj.105.074690 |
Bibtex: | @article{LENZ2006255, title = {First Steps of Retinal Photoisomerization in Proteorhodopsin}, journal = {Biophysical Journal}, volume = {91}, number = {1}, pages = {255-262}, year = {2006}, issn = {0006-3495}, doi = {https://doi.org/10.1529/biophysj.105.074690}, url = {https://www.sciencedirect.com/science/article/pii/S0006349506717258}, author = {Martin O. Lenz and Robert Huber and Bernhard Schmidt and Peter Gilch and Rolf Kalmbach and Martin Engelhard and Josef Wachtveitl}, abstract = {The early steps (<1ns) in the photocycle of the detergent solubilized proton pump proteorhodopsin are analyzed by ultrafast spectroscopic techniques. A comparison to the first primary events in reconstituted proteorhodopsin as well as to the well known archaeal proton pump bacteriorhodopsin is given. A dynamic Stokes shift observed in fs-time-resolved fluorescence experiments allows a direct observation of early motions on the excited state potential energy surface. The initial dynamics is dominated by sequentially emerging stretching (<150fs) and torsional (∼300fs) modes of the retinal. The different protonation states of the primary proton acceptor Asp-97 drastically affect the reaction rate and the overall quantum efficiencies of the isomerization reactions, mainly evidenced for time scales above 1ps. However, no major influence on the fast time scales (∼150fs) could be seen, indicating that the movement out of the Franck-Condon region is fairly robust to electrostatic changes in the retinal binding pocket. Based on fs-time-resolved absorption and fluorescence spectra, ground and exited state contributions can be disentangled and allow to construct a reaction model that consistently explains pH-dependent effects in solubilized and reconstituted proteorhodopsin.} } |
Fourier domain mode locking (FDML): Three-dimensional OCT imaging at 906 frames per second, in 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference , IEEE, 052006. pp. 1-2.
DOI: | 10.1109/CLEO.2006.4627914 |
Bibtex: | @INPROCEEDINGS{4627914, author={Huber, R. and Wojtkowski, M. and Fujimoto, J. G.}, booktitle={2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference}, title={Fourier Domain Mode Locking (FDML): Three-dimensional OCT imaging at 906 frames per second}, year={2006}, volume={}, number={}, pages={1-2}, abstract={Fourier domain mode locking is a new operation regime of lasers. Highly chirped frequency swept waveforms rather than short pulses are generated. The mechanism and its application for ultrahigh-speed biomedical OCT imaging are discussed.}, keywords={}, doi={10.1109/CLEO.2006.4627914}, ISSN={2160-9004}, month={May},} |
Fourier Domain Mode Locking (FDML): A new laser operating regime and applications for optical coherence tomography, Optics Express , vol. 14, no. 8, pp. 3225 - 3237, 04 2006.
DOI: | 10.1364/OE.14.003225 |
Bibtex: | @article{Huber:06, author = {R. Huber and M. Wojtkowski and J. G. Fujimoto}, journal = {Opt. Express}, keywords = {Optical coherence tomography; Lasers, tunable; Frequency modulated lasers; Full field optical coherence tomography; Laser operation; Light fields; Medical imaging; Mode locking}, number = {8}, pages = {3225--3237}, publisher = {Optica Publishing Group}, title = {Fourier Domain Mode Locking (FDML): A new laser operating regime and applications for optical coherence tomography}, volume = {14}, month = {Apr}, year = {2006}, url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-14-8-3225}, doi = {10.1364/OE.14.003225}, abstract = {We demonstrate a new technique for frequency-swept laser operation--Fourier domain mode locking (FDML)--and its application for swept-source optical coherence tomography (OCT) imaging. FDML is analogous to active laser mode locking for short pulse generation, except that the spectrum rather than the amplitude of the light field is modulated. High-speed, narrowband optical frequency sweeps are generated with a repetition period equal to the fundamental or a harmonic of cavity round-trip time. An FDML laser is constructed using a long fiber ring cavity, a semiconductor optical amplifier, and a tunable fiber Fabry-Perot filter. Effective sweep rates of up to 290 kHz are demonstrated with a 105 nm tuning range at 1300 nm center wavelength. The average output power is 3 mW directly from the laser and 20 mW after post-amplification. Using the FDML laser for swept-source OCT, sensitivities of 108 dB are achieved and dynamic linewidths are narrow enough to enable imaging over a 7 mm depth with only a 7.5 dB decrease in sensitivity. We demonstrate swept-source OCT imaging with acquisition rates of up to 232,000 axial scans per second. This corresponds to 906 frames/second with 256 transverse pixel images, and 3.5 volumes/second with a 256{\texttimes}128{\texttimes}256 voxel element 3-D OCT data set. The FDML laser is ideal for swept-source OCT imaging, thus enabling high imaging speeds and large imaging depths.}, } |
"Measurements of Gas Temperature in a HCCI Engine Using a Fourier Domain Mode Locking Laser" SAE Technical Paper 2006-01-1366, 04 2006.
DOI: | 10.4271/2006-01-1366 |
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} } |
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, 022006. pp. 60790U.
DOI: | 10.1117/12.648880 |
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} } |
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, 022006. pp. TuB2.
DOI: | 10.1364/LACSEA.2006.TuB2 |
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
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, Dec. 2005. Optica Publishing Group.
DOI: | 10.1364/OPEX.13.010523 |
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.}, } |
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, Oct.2005. pp. 58611B.
DOI: | 10.1117/12.641732 |
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} } |
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) , 052005. pp. CP3-5-THU.
Three Dimensional Waveguide Splitters Fabricated in Glass Using a Femtosecond Laser Oscillator - Technical Digest (CD), in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science and Photonic Applications Systems Technologies , Optica Publishing Group, 052005. pp. CThCC4.
DOI: | 10.1109/CLEO.2005.202363 |
Bibtex: | @inproceedings{Sharma:05, author = {V. Sharma and A. M. Kowalevicz and R. Huber and J. G. Fujimoto and K. Minoshima}, 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 = {Optical design and fabrication; Microstructure fabrication; Ultrafast optics; Ultrafast processes in condensed matter, including semiconductors; Femtosecond lasers; Femtosecond pulses; Free electron lasers; High numerical aperture optics; Three dimensional fabrication; Ti:sapphire lasers}, pages = {CThCC4}, publisher = {Optica Publishing Group}, title = {Three dimensional waveguide splitters fabricated in glass using a femtosecond laser oscillator}, year = {2005}, url = {https://opg.optica.org/abstract.cfm?URI=CLEO-2005-CThCC4}, abstract = {Three-dimensional optical waveguide devices are fabricated in glass using femtosecond pulses from an extended cavity Ti:sapphire laser oscillator. We demonstrate increased device densities by fabricating highly symmetric 1:N waveguide splitters in three dimensions.}, } |
Text