Fabricating an optics wafer includes providing a wafer comprising a core region composed of a glass-reinforced epoxy, the wafer further comprising a first resin layer on a top surface of the core region and a second resin layer on a bottom surface of the core region. The wafer further includes vertical transparent regions that's extend through the core region and the first and second resin layers. The wafer is thinned from its top surface and its bottom surface so that a resulting thickness is within a predetermined range without causing glass fibers of the core region to become exposed. Optical structures ate provided on one or more exposed surfaces of at least some of the transparent regions.