Channel passband relative position independently regulatable one-passband two-channel filter

The invention provides a design method that can independently regulate the relative position of a pass band and two channels in a channel pass-band light filtering piece, adopting a triple-symmetrical structure based on Fabry-Perot etalon. It is different from traditional narrow-band light filtering piece in regulating independently the positions of a pass band and two channels by changing the thickness of several middle layers, respectively, and thus overcomes the position coherence phenomenon caused by the position regulation of the channel and pass band. It introduces the concrete structural design of the light filtering piece as well as the calculated spectrum characteristic of the one-channel two-pass band light filtering piece. It can be applied in the fields of optical detecting apparatus, space technique and so on.