Detaljeret beskrivelse

Optical coherence tomography

Contacts:

Alessio Stefani, DTU Fotonik, 4525-3841 (alste@fotonik.dtu.dk)

Michael Frosz, DTU Fotonik, 4525-6369 (mhfr@fotonik.dtu.dk)

http://www.mpof.fotonik.dtu.dk

 

OCT
An example of an OCT image giving a cross-sectional view of a human finger and the attached fingernail (left side). The finger is pointing from right to left.

Optical coherence tomography is a bio­medical imaging technique, which can be used to make cross-sectional images of tissue. In principle, OCT is analogous to ultrasound: a laser beam is directed onto the sample and by cleverly mea­suring the reflected light one can extract structural information about the tissue beneath the surface. The image res­o­lution is com­parable to that obtained with a micro­­scope (a few microns), but unlike microscopy this technique can be used non-invasively, i.e. without cutting a tissue sample from the patient.

 

The technique could also be used to make non-contact measurements of objects moving quickly past the detector, thereby allowing fast inspection during manufacturing of objects where micron-scale precision is crucial. Specifically, one could use OCT to check the structural diameters of optical fibres during the drawing process. This would be very useful in the production of so-called photonic crystal fibres (PCFs); PCFs of silica glass are today mainly produced by the Danish company Crystal Fibre A/S. Also, DTU Fotonik is one of the few places in the world where PCFs made of polymer are made. This project can therefore have a large significance for both industry and research.

 

The project can be balanced equally between theory and practice. You should first learn the physical basis for the technique, and then start building your own setup.