Volumetric optical devices

A device including:

• a porous scaffold;
• and
• a coating forming a surface of the porous scaffold, the coating including:
• the surface characterized by a surface refractive index;
• and
• a transition region diffused into the porous scaffold, the transition region characterized by a refractive index gradient that transitions between the surface refractive index and a scaffold refractive index that characterizes an internal volume of the porous scaffold.

A method including:

• determining to optically write a voxel at a selected point within a write field at a selected effective power;
• using the selected point and the selected effective power performing a lookup in an adjusted power data structure;
• obtaining, in response to the lookup and from the adjusted power data structure, an adjusted power at which to set a writing illumination source to illuminate the selected point at the selected effective power;
• and
• optically writing the voxel at the selected point with the writing illumination source set at the adjusted power.