Elimination of depth degeneracy in optical frequency-domain imaging through polarization-based optical demodulation.
A novel optical frequency-domain imaging system is demonstrated that employs a passive optical demodulation circuit and a chirped digital acquisition clock derived from a voltage-controlled oscillator. The demodulation circuit allows the separation of signals from positive and negative depths to better than 50 dB, thereby eliminating depth degeneracy and doubling the imaging depth range. Our system design is compatible with dual-balanced and polarization-diverse detection, important techniques in the practical biomedical application of optical frequency-domain imaging.
Harvard Medical School and the Wellman Center for Photomedicine, Massachusetts General Hospital, Boston 02114, USA. bvakoc@partners.org
B J
BJ
Vakoc
S H
SH
Yun
G J
GJ
Tearney
B E
BE
Bouma
D000703:Analog-Digital Conversion; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D055095:Optics and Photonics / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods