Interference suppression of light backscattering through oblique deposition of high-reflectivity multilayers: a theoretical analysis.

We demonstrate a theoretical approach whereby light backscattering toward the incident beam can be suppressed entirely for a high-reflectivity, rough-surfaced multilayer mirror fabricated using oblique deposition, such that the interface relief is replicated at a certain angle β to the sample normal. The mirror comprises two parts: a main (lower) multilayer consisting of N identical bi-layers growing at the angle β to the mirror normal, and an additional bi- or tri-layer forming the topmost section of the mirror, which grows at another angle β. We show that choosing appropriate growth angles β and β results in a disappearance of backscattering toward the incident beam due to the destructive interference of waves scattered from the main multilayer and uppermost bi- or tri-layer.