Optimal Design of a Narrow-band Filter Compensate Layers Used in WDM Optical Fiber Communication System

摘要

The film structure of a multiple-cavity narrow-band interference filter is always used as DEMUX in WDM optical fiber communication system. To ensure the repeat of the film coating results, the optical thickness of every layer in this film structure is designed to be the itneger multiple of the quarter of the monitor wavelength. But such design, which is only composed of regular layers, cannot meet the desire. Therefore, a design method, in which the film structure of a few irregular layers is added to the multiple-layer standard film structure, is introduced in this paper. Thus, the design desire can be basically satisfied. In the design, the optical thickness of the irregular layers is obtaiend by the optimal methody with computer. An estimate function of the optimizing is made in this paper. A program is bilt in MATLAB programming language. By using the program, the thickness of the irregular compensates film on whatever multiple-layer regular film structure can be optimized.