A resonant laser powered micro accelerator platform capable of producing relativistic or near relativistic electrons and, optionally, x-rays. The apparatus has a pair of parallel slab-symmetric dielectric slabs that are separated by a narrow vacuum gap that is preferably tapered. The slabs have a top surface with reflective layers with many periodic slots creating longitudinal periodicity in the structure fields when laser light is directed on the reflectors in one embodiment. Electrons introduced into the gap are accelerated along the length of the slabs. The reflective surface of the slabs is preferably a laminate of alternating layers of high index and low index of refraction materials.