Quadrature interferometry based on 3×3 fiber couplers could be used to double the effective imaging depth in Swept- Source Optical Coherence Tomography. This is due to its ability to suppress the complex conjugate artifact naturally. We present theoretical and experimental results for a 3×3 Mach-Zehnder interferometer using a new unbalanced differential optical detection method. The new interferometer provides simultaneous access to complementary phase components of the complex interferometric signal. No calculations by trigonometric relationships are needed. We demonstrate a complex conjugate artifact suppression of 27 dB obtained in a swept-source optical coherence tomography using our unbalanced differential detection. We show that our unbalanced differential detection has increased the signal to- noise ratio by at least 4 dB compared to the commonly used balanced detection technique. This is due to better utilization of optical power.

Date Published: 12 August 2008
PDF: 8 pages
Proc. SPIE 7099, Photonics North 2008, 709909 (12 August 2008); doi: 10.1117/12.807440

Published in SPIE Proceedings Vol. 7099:
Photonics North 2008
Réal Vallée; Michel Piché; Peter Mascher; Pavel Cheben; Daniel Côté; Sophie LaRochelle; Henry P. Schriemer; Jacques Albert; Tsuneyuki Ozaki, Editor(s)