Preferred embodiments of the invention provide microcavity plasma lamps having a plurality of metal and metal oxide layers defining a plurality of arrays of microcavities and encapsulated thin metal electrodes. Packaging encloses the plurality of metal and metal oxide layers in plasma medium. The metal and metal oxide layers are configured and arranged to vary the electric field strength and total gas pressure (E/p) in the lamp. The invention also provides methods of manufacturing a microcavity plasma lamp that simultaneously evacuate the volume within the packaging and a volume surrounding the packaging to maintain an insignificant or zero pressure differential across the packaging. The packaging is backfilled with a plasma medium while also maintaining an insignificant or zero pressure differential across the packaging.