Figure 6
Fabrication and characterization of the diamond drumhead crystal C1 with two membranes. (a) A photograph of the crystal after drumhead fabrication, taken from the unmachined side. (b) A microscope image of the drumhead structure with two membranes M1 and M2 (light circles). (c) A 3D model of the crystal showing the drumhead structure from the machined side. (d) An RCI intensity map. (e)–(f) RCI color maps of FWHM and COM, respectively. (g)–(h) The 400 Bragg reflection rocking curves measured (black) in 100 µm × 100 µm regions of drumhead membranes M1 and M2, respectively, versus theoretical curves (red) calculated with a membrane thickness of (g) 16 µm and (h) 16.5 µm. (i) Wavefront phase error maps remeasured after drumhead fabrication in the region of the two membranes. (j) Distribution of the r.m.s. phase error in the 100 µm × 100 µm regions. |