Fig. 3: Subsurface line voxel dimensions.
From: Direct laser writing of volumetric gradient index lenses and waveguides
a Scanning electron microscopy of fractured cross sections of line voxels printed inside PSi at different average laser powers. The shape of the voxel becomes more asymmetric and elliptical with increasing laser power, as seen by the contrast between the polymerized region and the porous background. Scale bars are 250 nm. b, d Best-fit ellipses for the PSFs in PSi (b) and PSiO2 (d) in the xz-plane for the indicated printing laser powers. c, e The x and z dimensions of the voxels printed inside PSi (c) and PSiO2 (e) versus the average laser power. All line voxels are printed with a scan speed of 10 mm s−1
