Complex photonics

Technological boost is essential for all aspect of our research agenda. Our activities focus on imaging with new types of multimode optical fibers. We focus mainly on gradient-index fibers, which offer low dispersion as well as high resilience to bending.
We develop new the fiber terminations and end-face coatings to improve applicability in challenging conditions.
For fast and reliable image recovery we develop advanced data processing algorithms using parallel processing.
Further we focus on development of modular imaging systems and user-friendly interface that may by readily deployed in laboratories of our partners.
Lastly we develop the applications of MEMS technology for ultra-fast wavefront shaping required for methods of holographic endoscopy.

Better understanding of light-transport processes will enable faster and more precise light control especially in highly dynamic regimes of imaging. Multimode fibres deliver light signals in the form of apparently random speckled patterns, in a very similar fashion to other random media. Although multimode fibres feature remarkably faithful cylindrical symmetry they are frequently classified as unpredictable optical systems. Our research challenges this commonly held notion. We develop holographic geometries for complete and accurate analysis of light signals traveling throughout the fibre and verify the observations by advanced numerical modelling. Harnessing the predictability of multimode waveguides in endoscopy will allow for numerous enhancements of deep tissue imaging.

Stephen Simpson
Simpson@isibrno.cz
+420 541 514 132

Label-free imaging with chemical contrast allows for the detection of the composition of tissues without the need of further chemical interventions (staining). It is based on the principles of Raman spectroscopy and it has been exploited in applications such as identifying bacteria and imaging lipid distribution in cells (relevant for cell metabolism and related disease conditions). Combined with holographic endoscopy, it has a great promise as a method for diagnosing tumors in sensitive and inaccessible locations such as pancreas and ovary, without performing a biopsy and associated time consuming histopathology.
We aim to implement Raman imaging through a multimode fiber combined with several advanced imaging modalities.

In-vivo applications represents the culmination of our efforts to introduce new imaging platform for observations inside living organisms. The methodology of holographic endoscopy utilises light transport through standard multimode optical fibres to perform lensless minimally invasive micro-endoscopy. These possibilities represent a great promise for in-vivo bio-medical imaging, allowing advanced methods such microscopy to be introduced into deep regions of unrestraint and awake animal models. Our current research efforts focus on allowing these methods in flexible geometries, increasing the speed of acquisition and first in-vivo experiments in animal models.

Johanna Trägårdh
Johanna@isibrno.cz
+420 541 514 135