An optical imaging system includes an array of optical imaging devices each comprising a device for providing charge amplification in a gaseous medium. A preferred embodiment of such a charge amplification device includes a substrate having a cavity defined therein, an anode surface positioned in the bottom of the cavity and a cathode positioned adjacent the cavity opening. A drift electrode is juxtaposed over the substrate opposite the cavity and defines a region containing a gaseous medium. As ionized charge pairs are established in the gaseous medium due to radiation provided by an external radiation source, electrons are attracted toward the anode where they undergo avalanche multiplication with the gaseous medium under the influence of an intense electric field established between the anode and cathode. As a result of the avalanche process, the gaseous medium within the avalanche region emits photons, predominately in the UV region, which are collected by the substrate and provided to a photon detector coupled thereto. The substrate is preferably provided with a wavelength shifting material operable to shift the UV light to the visible region, where it is thereafter imaged by the photon detector using, for example, conventional CCD camera technology.