Design and manufacture method of micro step reflector for static Fourier transform spectrometer

The mirror of static Fourier transform spectrometer employs a micro stepped mirror, which allows the spectrometer to perform simultaneous sampling at various levels without a space driven device. Based on theoretical analysis and test data analysis and comparison, the method of using wedge shaped glass strips is eventually determined to make micro stepped reflection mirror.This method uses general optical elements and process to manufacture 1 wedge shaped glass block and 10 wedge shaped glass strips, then selects wedge shaped glass strip by sequence and cements them on the cant of wedge shaped glass block one by one, and uses UV adhesive to cement contact surface of adjacent wedge shaped glass strips.Horizontally it repeatedly pushs adjacent wedge shaped glass strip and uses instrumentation to measure adjacent stepped thickness until meeting the requirements, then cures UV adhesive with UV light.Steps above are repeated to create a micro step mirror with required step number.Compared with other methods, this method is safe and feasible, and has characteristics of consistency and step thickness controllable. It can be used to produce micro step mirror with height error of step only 0.124 μm and surface roughness 12 nm, satisfying system design requirements.