Phase-stable swept source OCT angiography in human skin using an akinetic source

Zhe Chen; Mengyang Liu; Michael Minneman; Laurin Ginner; Erich Hoover; Harald Sattmann; Marco Bonesi; Wolfgang Drexler; Rainer A Leitgeb

doi:10.1364/BOE.7.003032

Phase-stable swept source OCT angiography in human skin using an akinetic source

Biomed Opt Express. 2016 Jul 12;7(8):3032-48. doi: 10.1364/BOE.7.003032. eCollection 2016 Aug 1.

Authors

Zhe Chen¹, Mengyang Liu¹, Michael Minneman², Laurin Ginner³, Erich Hoover², Harald Sattmann⁴, Marco Bonesi¹, Wolfgang Drexler¹, Rainer A Leitgeb³

Affiliations

¹ Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
² Insight Photonic Solutions, Inc., 300 S. Public Rd., Lafayette CO 80026, USA.
³ Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Währinger Gürtel 18-20, 1090 Vienna, Austria.
⁴ Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; Insight Photonic Solutions, Inc., 300 S. Public Rd., Lafayette CO 80026, USA.

Abstract

We demonstrate noninvasive structural and microvascular contrast imaging of human skin in vivo, using phase difference swept source OCT angiography (pOCTA). The pOCTA system employs an akinetic, all-semiconductor, highly phase-stable swept laser source which operates at 1340 nm central wavelength, with 37 nm bandwidth (at 0 dB region) and 200 kHz A-scan rate. The phase sensitive detection does not need any external phase stabilizing implementations, due to the outstanding high phase linearity and sweep phase repeatability within 2 mrad. We compare the performance of phase based OCTA to speckle based OCTA for visualizing human vascular networks. pOCTA shows better contrast especially for deeper vascular details as compared to speckle based OCTA. The phase stability of the akinetic source allows the OCTA system to show decent vascular contrast only with 2 B-scans. We compare the performance of using 2 versus 4 B-scans for calculating the vascular contrast. Finally, the performance of a 100 nm bandwidth akinetic laser at 1310 nm is investigated for both OCT and OCTA.

Keywords: (140.3600) Lasers, tunable; (170.0110) Imaging systems; (170.3880) Medical and biological imaging; (170.4500) Optical coherence tomography; (170.4580) Optical diagnostics for medicine.