We analyze the transmission characteristics of a Sagnac loop interferometer containing a polarization-dependent loss element and lossless polarization-converting elements by use of Jones matrices. We show that polarization independence in the transmission mode can be achieved in such a configuration and that maximum transmittance occurs when a half-wave plate is used for the polarization-converting element. The result is verified experimentally for a fiber acousto-optic tunable filter and cascaded long-period fiber gratings with either intrinsic or process-induced polarization-dependent filtering characteristics.
© 2005 Optical Society of America
(060.2340) Fiber optics and optical communications : Fiber optics components
(120.5790) Instrumentation, measurement, and metrology : Sagnac effect
(230.5440) Optical devices : Polarization-selective devices
Chang-Seok Kim, Bernard Choi, J. Stuart Nelson, Qun Li, Pedram Zare Dashti, and H. P. Lee, "Compensation of polarization-dependent loss in transmission fiber gratings by use of a Sagnac loop interferometer," Opt. Lett. 30, 20-22 (2005)