An UV/VUV-emitting plasma lamp comprising: two or more internal plates, each having an interior surface and an exterior surface; the internal plates positioned approximately parallel to one another; at least one array of microcavities formed in the interior surface of at least one of the internal plates with at least one of the internal plates being comprised of a material that allows transmission of radiation in the UV and VUV spectral regions; a gas or mixture of gases in which a glow discharge, plasma, is produced; the gas occupying the fixed volume between the internal plates and being in contact with the array of microcavities; a power supply and a plurality of electrodes electrically connected to the power supply designed to deliver a time-varying voltage; at least one of the plurality of electrodes being located on the exterior surface of each internal plate; the electrodes having an openness or transparency to radiation in the UV and VUV spectral regions that is above 85 %; optionally, one or more protective windows placed on the opposite side of at least one electrode in order to provide environmental protection thereto; and characterized by one or more spacers located between the interior surfaces of the internal plates, such that the spacers keep the approximately parallel internal plates separated at a predetermined fixed distance; wherein at least one spacer is a periphery spacer placed near the edge of the internal plates, the periphery spacer forming a hermetic seal with the internal plates; the spacers creating a fixed volume between the internal plates; wherein the time-varying voltage interacts with the gas, such that a spatially uniform, glow discharge, plasma, is formed both within the microcavities and within the fixed volume between the internal plates (5,) the glow discharge, plasma, emitting radiation that is in the UV/VUV spectral region. two or more internal plates, each having an interior surface and an exterior surface; the internal plates positioned approximately parallel to one another; at least one array of microcavities formed in the interior surface of at least one of the internal plates with at least one of the internal plates being comprised of a material that allows transmission of radiation in the UV and VUV spectral regions; a gas or mixture of gases in which a glow discharge, plasma, is produced; the gas occupying the fixed volume between the internal plates and being in contact with the array of microcavities; a power supply and a plurality of electrodes electrically connected to the power supply designed to deliver a time-varying voltage; at least one of the plurality of electrodes being located on the exterior surface of each internal plate; the electrodes having an openness or transparency to radiation in the UV and VUV spectral regions that is above 85 %; optionally, one or more protective windows placed on the opposite side of at least one electrode in order to provide environmental protection thereto; and characterized by one or more spacers located between the interior surfaces of the internal plates, such that the spacers keep the approximately parallel internal plates separated at a predetermined fixed distance; wherein at least one spacer is a periphery spacer placed near the edge of the internal plates, the periphery spacer forming a hermetic seal with the internal plates; the spacers creating a fixed volume between the internal plates; wherein the time-varying voltage interacts with the gas, such that a spatially uniform, glow discharge, plasma, is formed both within the microcavities and within the fixed volume between the internal plates (5,) the glow discharge, plasma, emitting radiation that is in the UV/VUV spectral region.