Abstract
Characterizing and real-time compensating the time-skew and phase-mismatch of the in-phase and quadrature (I/Q) signals, for phase-sensitive optical time-domain reflectometry (Φ-OTDR) with heterodyne detection, are the aims of this paper. After amplitude imbalances are compensated, there are still some intrinsic distortions in demodulated signals, which are generated from the time-skew and phase-mismatch of I/Q signals. A novel method, proposed in this paper, can separate the impacts from RF cable length-difference, fiber pigtail length-difference, and the non-orthogonality between I/Q signals, providing the basis for precise and real-time compensation. Both the theoretical analysis and the experimental demonstration are presented. It should also be noted that this method also fits for other heterodyne demodulation systems.
© 2018 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription