The Design And Experiment Of An Innovative Reconfigurable Optical Add-Drop Multiplexer

The reconfigurable optical add-drop multiplexer(ROADM)is a crucial component in the optical network which will be used in the Internet and digital television network, enhancing their performance, band width and speed. Because of unstable performance with various temperature, complicated structure, mechanical error and so on, a majority of ROADMs can not be applied to practice.In this thesis, a practical ROADM, constituted by a four-fiber collimator, several filters and a reflecting mirror,whose import, export, add-port, drop-port are located in one plane is advanced. Besides, an electromotor which is controlled by a controller and a driver can propel filters to move, consequently, added and dropped lightwave can be selected.A four-fiber collimator based on four fibers and a variable curvature lens has been developed for the novel ROADM. By using matrix optics method, the structure and optical parameters of the four fiber collimator, such as spheric radius, lens length, were obtained. Moreover, the propagation of the Gauss light field in the device was analyzed, and the results from the matrix optics method were testified.The structure and optical parameters of the ROADM were calculated, optimized and exhibited by Matlab GUI. Furthermore, the propagation of light field in the device, including its width and energy, was stimulated by RSOFT , and the energy concentration is over 90%.Two face to face arranged dual-fiber collimators which can substitute the four-fiber collimator have been used to verify the ROADM experimentally, and some results were obtained. Based on this, the experiment using a four fiber collimator was designed and the dispersive effect was analyzed.