The invention discloses a preparation process for evaporating a
cut-off film on the surface of
chalcogenide glass, and particularly relates to the technical field of
infrared optical detection.The preparation process comprises the following steps that S01, the initial vacuum degree before execution of a
coating machine is superior to 5.0 * 10 <-4 > Pa, the baking temperature ranges from 80 DEG C to 150 DEG C, and
ion source parameters are set as follows: the
cathode voltage ranges from 100 V to 300 V, and the
ion beam current ranges from 1 A to 4 A; s02, before
evaporation, carrying out
ion bombardment on the lens
chalcogenide glass for 3-10 minutes by the
coating machine; s03, plating a first layer of Ge on the
chalcogenide glass of the lens, and controlling the
evaporation rate to be 0.2-0.8 nm / s; s04, plating a second layer of ZnS on the first layer of Ge, and controlling the
evaporation rate to be 0.2-1.5 nm / s; s05, a third layer of YbF3 is plated on the second layer of ZnS, and the
evaporation rate is controlled to be 0.2-1 nm / s; s06, plating a fourth layer of ZnS on the third layer of YbF3, and controlling the
evaporation rate to be 0.2-1.5 nm / s; and S07, plating a fifth layer of Ge on the fourth layer of ZnS, wherein the
evaporation rate is controlled to be 0.2-0.8 nm / s. The thin film provided by the invention effectively solves the problems of stress between film
layers, film layer
adhesive force and good spectral performance.