As a kind of element for filtrating the light and selecting spectrum, Bandpass filter was used widely in optical fiber communication, analytic instrument and laser system. In allusion to the bandpass filter which is used in the 905nm infrared semiconductor laser system, the paper in theory analysed laser damage and optical stability, and put forward some advisable ways from material and technics angle, then finished the film design. All the experiments were completed on TXX-700 vacuum film machine, and we tested the spectrum characteristic with UV3150 spectrophotometer. According to the spectrum characteristic of bandpass filter and its changes after setting in the atmospheric environment, we improved the preparation technics., and finally achieved the satisfied bandpass filter. |