为了提高密集波分复用(DWDM)薄膜窄带滤光片制备的成品率，讨论了用于DWDM薄膜窄带滤光片在镀制过程中的监控方法及误差，采用Monte Carlo允差分析原理分析用于DWDM窄带滤光片膜层的容差，以便选择更易制备的膜系；计算膜层的Macleod极值灵敏度，得到所选膜系各个膜层的误差要求；模拟光学监控过程和计算膜层导纳，能够得到膜层制备过程中膜层之间膜厚的补偿关系。实验表明，据此制定的膜厚监控策略，对于DWDM窄带滤光片膜层的制备和保证成品率是非常关键的。

To improve the productivity of fabrication of the narrow band DWDM film filter,the monitoring method and error in coating this film is discussed. Monte Carlo method is used to model the tolerance of the layer for the filter,and the results are used to select the easy coating film system. The film thickness error of each layer is obtained by calculating the Macleod maximum sensitivity. The compensation of the film thickness between each layer is obtained by modeling the optical monitoring processes and the film admittance. The strategy of controlling the film thickness is obtained through the above measures,and the experiments have proved that this is crucial to coating the film for the filter and impoving the productivity.