Madita Göb

Doktorandin / PhD Student


Universität zu Lübeck
Institut für Biomedizinische Optik

Maria-Goeppert-Str. 1
23562 Lübeck
Gebäude MFC 1, Raum 2.24

Email:
Phone:
+49 451 3101 3234
Fax:
+49 451 3101 3233



Publikationen

2021

  • S. Lotz, C. Grill, M. Göb, W. Draxinger, J.P. Kolb and R. Huber: Cavity length control for Fourier domain mode locked (FDML) lasers with µm precision. Biomedical Optics Express, no. 12(5), pp. 2604-2616, 2021
    BibTeX Link
    @article{Lotz2021,
       author = {S. Lotz, C. Grill, M. Göb, W. Draxinger, J.P. Kolb and R. Huber},
       title = {Cavity length control for Fourier domain mode locked (FDML) lasers with µm precision},
       journal = {Biomedical Optics Express},
       volume = {12(5)},
       keywords={AG-Huber_FDML},
       pages = {2604-2616},
       url = {https://doi.org/10.1364/BOE.422898},
       year = {2021},
       type = {Journal Article}
    }
    
  • S. Lotz, C. Grill, M. Göb, W. Draxinger, J. P. Kolb and R. Huber: Characterization of the dynamics of an FDML laser during closed-loop cavity length control. in Fiber Lasers XVIII: Technology and Systems, no. 11665, pp. 236 - 241, SPIE, 2021
    BibTeX Link
    @inproceedings{LotzLASE2021,
    author = {S. Lotz, C. Grill, M. Göb, W. Draxinger, J. P. Kolb and R. Huber},
    title = {{Characterization of the dynamics of an FDML laser during closed-loop cavity length control}},
    volume = {11665},
    booktitle = {Fiber Lasers XVIII: Technology and Systems},
    editor = {Michalis N. Zervas},
    organization = {International Society for Optics and Photonics},
    publisher = {SPIE},
    pages = {236 -- 241},
    abstract = {In Fourier domain mode locked (FDML) lasers, extremely precise and stable matching of the filter tuning period and light circulation time in the cavity is essential for ultra-low noise operation. During the operation of FDML lasers, the ultra-low noise mode can be lost due to temperature drifts of the already temperature stabilized cavity resulting in increased intensity noise. Until now, the filter frequency is continuously regulated to match the changing light circulation time. However, this causes the filter frequency to constantly change by a few mHz and leads to synchronization issues in cases where a fixed filter frequency is desired. We present an actively cavity length controlled FDML laser and a robust and high precision feedback loop algorithm for maintaining ultra-low noise operation. Instead of adapting the filter frequency, the cavity length is adjusted by a motorized free space beam path to match the fixed filter frequency. The closed-loop system achieves a stability of ~0.18 mHz at a sweep repetition rate of ~418 kHz which corresponds to a ratio of 4×10<sup>-10</sup>. We investigate the coherence properties during the active cavity length adjustments and observe no noise increase compared to fixed cavity length. The cavity length control is fully functional and for the first time, offers the possibility to operate an FDML laser in sweet spot mode at a fixed frequency or phase locked to an external clock. This opens new possibilities for system integration of FDML lasers.},
    keywords = {AG-Huber_FDML, FDML, Fourier domain mode locking, laser beating, tunable laser, optical coherence tomography, OCT},
    year = {2021},
    URL = {hhttps://doi.org/10.1117/12.2578514}
    }

2020

  • Tom Pfeiffer and Madita Göb and Wolfgang Draxinger and Sebastian Karpf and Jan Philip Kolb and Robert Huber: Flexible A-scan rate MHz-OCT: efficient computational downscaling by coherent averaging. Biomed. Opt. Express, no. 11, pp. 6799-6811, OSA, Nov, 2020
    BibTeX Link
    @article{Pfeiffer:20,
    author = {Tom Pfeiffer and Madita G\"{o}b and Wolfgang Draxinger and Sebastian Karpf and Jan Philip Kolb and Robert Huber},
    journal = {Biomed. Opt. Express},
    keywords = {AG-Huber_OCT; High speed imaging; Image quality; Optical coherence tomography; Swept lasers; Swept sources; Systems design},
    number = {11},
    pages = {6799--6811},
    publisher = {OSA},
    title = {Flexible A-scan rate MHz-OCT: efficient computational downscaling by coherent averaging},
    volume = {11},
    month = {Nov},
    year = {2020},
    doi = {10.1364/BOE.402477},
    abstract = {In order to realize adjustable A-scan rates of fast optical coherence tomography (OCT) systems, we investigate averaging of OCT image data acquired with a MHz-OCT system based on a Fourier Domain Mode Locked (FDML) laser. Increased system sensitivity and image quality can be achieved with the same system at the cost of lower imaging speed. Effectively, the A-scan rate can be reduced in software by a freely selectable factor. We demonstrate a detailed technical layout of the strategies necessary to achieve efficient coherent averaging. Since there are many new challenges specific to coherent averaging in swept source MHz-OCT, we analyze them point by point and describe the appropriate solutions. We prove that coherent averaging is possible at MHz OCT-speed without special interferometer designs or digital phase stabilization. We find, that in our system up to \&\#x223C;100x coherent averaging is possible while achieving a sensitivity increase close to the ideal values. This corresponds to a speed reduction from 3.3 MHz to 33 kHz and a sensitivity gain of 20 dB. We show an imaging comparison between coherent and magnitude averaging of a human finger knuckle joint in vivo with 121\&\#x00A0;dB sensitivity for the coherent case. Further, the benefits of computational downscaling in low sensitivity MHz-OCT systems are analyzed.},
    }
    

2019

  • Madita Göb,Tom Pfeiffer,Robert Huber: Towards combined optical coherence tomography and multi-spectral imaging with MHz a-scan rates for endoscopy. in Proc. SPIE 11078, Optical Coherence Imaging Techniques and Imaging in Scattering Media III, 110780Y, no. 11078, 2019
    BibTeX Link Datei
    @proceeding{Goeb2019,
    author = {Madita Göb,Tom Pfeiffer,Robert Huber},
    title = {Towards combined optical coherence tomography and multi-spectral imaging with MHz a-scan rates for endoscopy},
    volume = {11078},
    year = {2019},
    
    URL = {  https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11078/110780Y/Towards-combined-optical-coherence-tomography-and-multi-spectral-imaging-with/10.1117/12.2526796.short},
    keywords = {AG-Huber_OCT},
    booktitle =    {Proc. SPIE 11078, Optical Coherence Imaging Techniques and Imaging in Scattering Media III, 110780Y},
    eprint = {}
    }