Analysis of the Requirements to the Accuracy of Diffractively Reflecting Coatings Manufacturing

One of the main problems of modern laser alarm systems is appearance of false alarms in difficult weather conditions (fog, rain, snow) because of reduction of the environment transparency. A promising solution is creation of “laser barriers” with the help of diffractively reflecting coatings as reflective elements. But the properties of those coatings depend considerably on the manufacturing process. If a coating was produced with errors, the coherent component of the total power reflected from a diffractively reflecting coating could decrease and the diffuse component (arising due to scattering by roughness) increase. Besides, the coating could scatter power in directions that do not correspond to the directions of the diffraction maxima. The presented paper substantiates the requirements to the accuracy of diffractively reflecting coatings manufacturing on the basis of analysis of the angular distribution functions of the reflected power.