https://doi.org/10.1051/epjconf/202430904003
Advancing Optical Coherence Tomography through Opto-Electronic Frequency Shifting
1 Centre for Medical Engineering and Technology, School of Science and Engineering, University of Dundee, Nethergate DD1 4HN, Dundee, Scotland, UK
2 Optos PLC, Queensferry House, Enterprise Way, Dunfermline, KY11 8GR, Scotland, UK
* e-mail: t.vettenburg@dundee.ac.uk
Published online: 31 October 2024
Optical Coherence Tomography (OCT) stands out for its ability to combine the high resolution of microscopy with the penetration-depth of clinical imaging. However, in practice this is still limited to a few millimetres. Interestingly, the imaging-depth of the latest swept-source systems is not limited by their spectral width but by the analog-to-digital sampling rate. In lieu of slow reference arm length adjustments, we leverage opto-electronic frequency shifting. This allows for depth adjustments on the microsecond timescale and a modest detector bandwidth of 200MHz. The opto-electronic scheme immediately gives us access to an 8mm range, a fourfold increase over the nominal 2mm range of the source. Moreover, by circumventing the need for a mechanical reference arm, changes in the axial displacement of the sample can be compensated in real-time. This makes it attractive for imaging arbitrarily-curved surfaces. We showcase this with wide-field OCT imaging of the curved retina.
© The Authors, published by EDP Sciences, 2024
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
