| 摘要 |
PURPOSE:To improve the transmission factor and to eliminate ripples in an interference filter by placing an interference layer (A) comprising thick film layers adjacently to an interference layer (B) comprising thin film layers and by disposing another interference layer (C) comprising layers having an intermediate thickness to the outer side of (A) or (B). CONSTITUTION:An interference layer 4 comprising relatively thin film layers and an interference layer 5 comprising relatively thick layers are arranged in an adjascent relation and by providing an interference layer 6 having an intermediate film thickness as an outer layer of 4 or 5. In this way, a filter B with less ripple as compared to an interference filter A having layers with intermediate film thickness in the intermediate part. |
