Video lecture series: Fundamentals of Fourier-Domain OCT

Here we release a new lecture series "Fundamentals of Fourier-domain optical coherence tomography." This is a series of five lectures given at University of Tsukuba by Yoshiaki Yasuno, and is aiming at educating students who newly study optical coherence tomography. 

I believe this is a good entering points for anyone starting OCT related research/study. 

The five videos are available at a YouTube playlist. 

>> YouTube Playlist "Fundamentals of Fourier-domain OCT."

Publication: Holographic refocusing of polarization-sensitive OCT

Our colleagues Lida Zhu recently published a new method to increase the resolution and measurement accuracy of polarization-sensitive optical coherence tomography (PS-OCT).

PS-OCT is an extension of OCT which provides three-dimensional distribution of quantitative polarization property of living samples. However, its measurement always exhibit optical imperfection, such as defocus. Lida showed for the first time that such imperfection results in inaccurate polarization measurement of PS-OCT. In addition, he introduced holographic refocusing to PS-OCT and successfully reduces such inaccuracy. This accuracy correction was experimentally demonstrated by measuring several phantom samples and biological samples such as a zebrafish and an ex vivo chicken muscle.

The details are published in Biomedical Optics Express.

Citation: L. Zhu, S. Makita, D. Oida, A. Miyazawa, K. Oikawa, P. Mukherjee, A. Lichtenegger, M. Distel, and Y. Yasuno, "Computational refocusing of Jones matrix polarization-sensitive optical coherence tomography and investigation of defocus-induced polarization artifacts," Biomed. Opt. Express 13, 2975-2994 (2022).

>> Full-length article (open access).

 私たちの研究室の Lida Zhu さんが偏光感受型OCT（PS-OCT）の分解能と偏光計測精度を向上させる新しい方法を発表しました。

PS-OCT は生体試料の偏光特性を定量的に計測するような機能拡張されたOCT技術です。しかし、その測定には常にデフォーカスなどの光学的欠陥がつきまといます。Lida さんは本研究で、このような光学的欠陥がPS-OCTで計測される偏光特性値を不正確にする（偏光特性値にシステミックな誤差を生じさせる）ことを初めて示しました。さらに、ホログラフィックリフォーカシングをPS-OCTに導入することで、この計測誤差を低減することに成功しました。この誤差低減方法はゼブラフィッシュなどの生体試料、及び様々な疑似試料（ファントム）を測定することで実験的に実証されました。

この研究の詳細は、Biomedical Optics Expressに掲載されています。

L. Zhu, S. Makita, D. Oida, A. Miyazawa, K. Oikawa, P. Mukherjee, A. Lichtenegger, M. Distel, and Y. Yasuno, "Computational refocusing of Jones matrix polarization-sensitive optical coherence tomography and investigation of defocus-induced polarization artifacts," Biomed. Opt. Express 13, 2975-2994 (2022).

>> Full-length article (open access).