Research On Bidirectional Reconfigurable Optical Add-Drop Multiplexer Based On Thin Flim Fliter

Bidiretional reconfigurable optical add-drop multiplexer(B-ROADM)with the ability of dynamic configuration will be an important foundation for All-optical networks and bidiretional WDM networks. As one of the core equipments in optical transport networks and metro optical networks, ROADM, compared with the traditional OADM, can flexibly offer network management based on wavelength, which brings convenience of multi- -service as well as low-cost for the network operators. The research of this thesis focuses on a fully ROADM based on TFF(Thin Film Fliter).In this paper, a modified Add/Drop unit is presented after reviewing the recent progress for OADM researches. The design contains three basic optical components: thin film filter,C-lens collimators and 2×2 optical switch. The characteristics of these three components will afect the final performances of the Add/Drop Unit.In this paper we studied the wavelength filtering principles of thin film filter through Wave Optics theory and got the numerical relationship between the incident angle of incident ray and central wavelength of the thin film filter; we studied the characteristics of C-lens collimator through Gauss Optics and Matrix Optics theories. Then we introduced three types of misalignment between C-lens collimators and the excess loss of the collimator due to the misalignment. We especially studied the reflective insertion loss caused by thin film filter because of its diferent position. All of above is extremely useful for the adjusting and making of the Add/Drop unit.Then we designed the test system of the Add/Drop unit and gave the test results. The results indicate that our design has excellent performances. Its configuration is simple compared with the traditional OADM system and it's cost is low.Based on the Add/Drop unit, we designed a novel parallel B-ROADM and simulated with the software"OptiSystem".