Performance analysis of DWDM systems with optical add drop multiplexers and optical cross connects

Abstract

This thesis deals with Performance analysis of Optical Add /drop multiplexers and optical Cross connects for Dense Wavelength Division Multiplexing system. It is essential to add/remove different channels in an optical communication system. The OADM provides flexibility and greater connectivity in the optical communication system. The OXC permits the system to be reconfigured on a channel by channel basis to optimize and exchange signals pattern, facilitate growth of network and increases network survivability. The sharing of system devices like OXADM, amplifiers and ROADM is permitted by the grouping of a multiple channels on a single fiber which results in cost savings. The Optical cross add drop multiplexer provides adding/dropping function and cross connecting signals similar to OADM and OXC in the optical system. Reconfigurable add drop multiplexer enables many channels which carry data to be added/dropped from optical fiber port without the need of optical-electrical-optical conversion. The designing and investigation of OXC, OADM using MZI-techniques, OADM based on FBG-circulator and ROADM based on DCE, PLC and WSS in fiber optical communication system is presented. Firstly, an optical system performance in terms of crosstalk with OADM based on MZI, MZI-semiconductor optical amplifier and MZI-FBG techniques placed at 20 km point of a 40 km link obtained at 8 × 10 Gbps with 0.1 nm channel spacing has been evaluated and found that with the MZI-FBG based OADM, the signal can be transmitted with very less bit error rate and improved Quality value whereas MZI-SOA based OADM shows the worst results. The dense WDM system with optical add drop multiplexer placed at 35 km point of a 70 km link has also been investigated and is found that MZI-FBG based OADM and OADM based on MZI provide better results with covered transmission distance (150km) at channel spacing of 0.1 nm and 10 Gbps bit rate without using DCF and amplifier. It is observed that the worst case is with the MZI-SOA based OADM.