Diffraction performance of an elastomeric grating coated via oblique-angle deposition of Cu

Abstract

Elastomeric gratings are used as controllable optical elements in various systems, particularly as dynamic beam scanners, but the diffraction performance is compromised when the grating is under strain. We use the oblique-angle deposition in coating a silicone grating to overcome this limitation. The grating is then tested in diffraction experiments while in one-directional stretching mode with a maximum strain of 2.7%. Based on the results, OAD at 80◦ with the grating lines and vapor flux aligned improves the diffraction performance of the grating as compared to non-OAD. Without applied strain, it was shown to increase the efficiency by 31%. When under strain, it was shown to decrease the efficiency loss and produce the largest diffraction angle variability, ∆θ = 4.01◦.  However, with the grating lines and vapor flux in perpendicular configuration in OAD, the efficiency even decreased by 26%.