@article{10902/34511,
year = {2024},
month = {11},
url = {https://hdl.handle.net/10902/34511},
abstract = {Significance: Optical coherence tomography (OCT) images are prone to image artifacts due to the birefringence of the sample or the optical system when a polarized light source is used for imaging. These artifacts can lead to degraded image quality and diagnostic information. 
Aim: We aim to mitigate these birefringence-related artifacts in OCT images by adding a depolarizer module in the reference arm of the interferometer. 
Approach: We investigated different configurations of liquid crystal patterned retarders as pseudo-depolarizers in the reference arm of OCT setups. We identified the most effective depolarization module layout for polarization artifact suppression for a spectral-domain OCT system based on a Michelson and a Mach-Zehnder interferometer. 
Results: The performance of our approach was demonstrated in an achromatic quarter-wave plate allowing the selection of a variety of sample polarization states. A substantial improvement of the OCT signal magnitude was observed after placing the optimal depolarizer configuration, reducing the cross-polarization artifact from 5.7 to 1.8 dB and from 8.0 to 1.0 dB below the co-polarized signal for the fiber-based Michelson and Mach-Zehnder setup, respectively. An imaging experiment in the birefringent scleral tissue of a post-mortem alpine marmot eye and a mouse tail specimen further showcased a significant improvement in the detected signal intensity and an enhanced OCT image quality followed by a drastic elimination of the birefringence-related artifacts. 
Conclusions: Our study presents a simple yet cost-effective technique to mitigate birefringence-related artifacts in OCT imaging. This method can be readily imple mented in existing OCT technology and improve the effectiveness of various OCT imaging applications in biomedicine.},
organization = {The authors thank Andreas Hodul, Quang Nguyen, Bernhard Reisenauer, Antonia Lichtenegger, Lisa Greutter, Yash Patel, Prajakta Belekar, Sarah Jurkowitsch, and Ireneusz Grulkowski for their support and technical assistance. Part of this research has been presented at Photonics West 2024 (presentation 12830-111). Funding from the Vienna Science and Technology Fund (Grant No. LS034-21), the Austrian Science Fund (Grant No. I6092-B), and the European Research Council (Grant Nos. 640396 and 101069344) is gratefully acknowledged.},
publisher = {Society of Photo-optical Instrumentation Engineers (SPIE)},
publisher = {Journal of Biomedical Optics, 2024, 29(11), 116001},
title = {Polarization-insensitive optical coherence tomography using pseudo-depolarized reference light for mitigating birefringence-related image artifacts},
author = {Varaka, Maria and Merkle, Conrad W. and May, Lucas and Worm, Sybren and Augustin, Marco and Fanjul Vélez, Félix and Lee, Hsiang-Chieh and Wöhrer, Adelheid and Glösmann, Martin and Baumann, Bernhard},
}