Opto-Electronics Review

Abstract

In this paper, a theoretical design of a novel passive optical line protection device for fiber to the home networks is presented and discussed. Such a device has been designed to overcome several issues of the conventional optical line protection which is based on a switching mechanism controlled electronically. The proposed design is suitable for multiplexed passive optical networks, especially, the dense wavelength division multiplexing technology. This unit is installed at both ends of the network and is composed of a 1×2 splitter to deliver the transmitted multiplexed signal to 2 optical paths and a 2×1 (99.9/0.1) coupler allowing an automatic control when a problem appears. Two optical line protection units exchange optical data through 2 dual fibers. In the case where the primary link suffers from a transmission problem, it automatically switches without any electronic control whatsoever to the backup link through a passive (99.9/0.1) coupler with an average total loss estimated to be of 3.2 dB.