High-quality single crystal diamond diffraction gratings fabricated by crystallographic etching

We demonstrate a novel method for fabricating single crystal diamond diffraction gratings based on crystallographic etching that yields high-quality diffraction gratings from commercially available <100> diamond plates. Both V-groove and rectangular gratings were fabricated and characterised using scanning electron microscopy and atomic force microscopy, revealing angles of 57 degrees and 87 degrees depending on the crystal orientation, with mean roughness below R-a = 5 nm on the sidewalls. The gratings were also optically characterised, showing good agreement with simulated results. The fabrication method demonstrated in this contribution shows the way for manufacturing high-quality diamond diffractive components that surpass existing devices both in quality and manufacturability. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement