title: 3x3 Mach-Zehnder interferometer with unbalanced differential detection for full-range swept-source optical coherence tomography.
abstract: Quadrature interferometry based on 3x3 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 3x3 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 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.
authors.affiliation: Institute for Microstructural Sciences, National Research Council Canada, Ottawa, Canada. linda.mao@nrc-cnrc.gc.ca
authors.forename: Youxin
authors.initials: Y
authors.lastname: Mao
authors.forename: Sherif
authors.initials: S
authors.lastname: Sherif
authors.forename: Costel
authors.initials: C
authors.lastname: Flueraru
authors.forename: Shoude
authors.initials: S
authors.lastname: Chang
mesh_terms: D000465:Algorithms; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005583:Fourier Analysis; D007090:Image Interpretation, Computer-Assisted; D007368:Interferometry / Q000295:instrumentation* / Q000379:methods; D008962:Models, Theoretical; D055095:Optics and Photonics; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods