Multiport polarization-independent wavelength-interleaving bidirectional quasicirculator

Abstract

An alternative type of multiport polarization-independent wavelength-interleaving bidirectional quasicirculator is proposed. It contains holographic spatial and polarization modules (HMs), a Lyot-Ohman filter (LOF), a quarterwave plate, and a mirror. Each HM contains a holographic spatial walk-off polarizer, a half-wave plate, and a glass plate. The LOF consists of three half-wave plates and three identical pairs of crystals. The functions of the HM and the LOF are described. Then, the operating principle and the performance of this quasicirculator are described and discussed. In this circulator, the signals in the even and odd channels can circulate with opposite handedness regardless of signal polarizations. It offers a high isolation level, polarization independence, low polarization-mode dispersion, parallel input/output ports and ease of increasing the number of ports.(c) 2008 Society of Photo-Optical Instrumentation Engineers.