Introduction:
Ultrafast optics and its subdomain optical frequency combs1,2 are a rapidly evolving domain enabling precision spectroscopy with increasingly reduced complexity of the light source hardware. Comb light sources cover wide spectrum3, can be implemented on chip scales4 and operate in mid-IR frequency range5. In parallel, the increased availability of computational power catalyzed a wide spreading of imaging that allows obtaining full spectral information, so called hyperspectral imaging (HSI). This modality enables enhanced analysis and classification of a 2D scene and adds additional versatility to the imaging systems. Notably, the HSI is finding intriguing uses6 in biological imaging7 for detection of diseases8 and monitoring pathologies9,10. The question arises; can we merge power of optical frequency combs and hyperspectral imaging to open new imaging capabilities for biological samples that could find use in research, medicine, agriculture or food safety?
Goal:
In this doctoral thesis work, the candidate will follow a systematic progression, beginning with the conceptual development of a new imaging system merging hyperspectral principals with optical frequency combs. Once developed, the system will undergo rigorous verification to ensure accuracy, reliability, and applicability in real-world scenarios using phantom samples. Ultimately, the goal is to demonstrate tangible and meaningful application by showcasing results by studying zebra fish embryo model.
Training:
The doctoral candidate would learn operating ultrafast laser technology and will get familiar with fundamental techniques related to them. Amongst them one can name: Carrier-envelope phase stabilization, optical frequency comb spectroscopy, optical field sampling techniques. The candidate will receive further insight into principles of biological sample imaging and hyperspectral image evaluation. Finally, the candidate will have the opportunity to develop and realize own experiments to pursuit the set-up goals which will lead to his independence in research.
References:
1. Picqué, N. & Hänsch, T. W. Frequency comb spectroscopy. Nat. Photonics 13, 146–157 (2019).
2. Diddams, S. A., Vahala, K. & Udem, T. Optical frequency combs: Coherently uniting the electromagnetic spectrum. Science (80-. ). 369, (2020).
3. Hutter, S. R., Sterk, P., Haller, S., Cimander, M. & Leitenstorfer, A. 1 PHz of Coherent Bandwidth from a Compact Fiber Device. Laser Photonics Rev. 00355, 1–7 (2025).
4. Wildi, T., Ulanov, A. E., Voumard, T., Ruhnke, B. & Herr, T. Phase-stabilised self-injection-locked microcomb. Nat. Commun. 15, 7030 (2024).
5. Rudenkov, A. et al. Chirped pulse waveguide amplifier. Opt. Express 33, 28935 (2025).
6. Bhargava, A. et al. Hyperspectral imaging and its applications: A review. Heliyon 10, e33208 (2024).
7. Lu, G. & Fei, B. Medical hyperspectral imaging : a review. J. Biomed. Opt. 19, 010901 (2014).
8. Bendel, N. et al. Detection of two different grapevine yellows in Vitis vinifera using hyperspectral imaging. Remote Sens. 12, 1–22 (2020).
9. Holmer, A. et al. Oxygenation and perfusion monitoring with a hyperspectral camera system for chemical based tissue analysis of skin and organs. Physiol. Meas. 37, 2064–2078 (2016).
10. Kulcke, A. et al. A compact hyperspectral camera for measurement of perfusion parameters in medicine. Biomed. Tech. 63, 547–556 (2018).
The candidate should have university knowledge of physics, mathematics and programming. Experience with laboratory work is of benefit, but it is not compulsory.