This invention relates to thin film lasers and is an improvement on the type of laser shown in U.S. Pat. No. 3,760,292. The laser of the present invention uses electric discharge excitation which is facilitated by the incorporation of an electrostrictive high dielectric coefficient element in the electrical circuit to enhance peak excitation, limit excitation to a thin film, and facilitate mixing of the lasing medium and dissipation of energy and discharge products. The preferred embodiment incorporates a gaseous thin film the active medium of which utilizes small molecules as disclosed in my co-pending applications Ser. No. 586,273, now U.S. Pat. No. 4,002,922, entitled Vacuum Ultraviolet Continuum Lamps and Ser. No. 586,374, now abandoned, entitled The Use Of Surface Acoustic Waves To Tune A Thin Film Laser.
The thin film laser of the present invention is expected to have its greatest use in producing laser radiation in the 1,000 A to 10,000 A region. Present dye lasers do not operate, and could not operate in the region below 4,000 A, without destruction of the dye. Dye lasers use optical pumping means. In contrast, the laser of the present invention utilizes electrical discharge excitation of molecules, particularly although not limited to, molecules the ground state of which is unbound so the unexcited molecule is instable (Kr.sub.2) or stable molecules with transitions to an unstable state (H.sub.2 (b.sup.3 .SIGMA..sup.+)). High pressure, typically in the range of 100 torr to 10,000 torr is preferred so that collisional processes dominate most radiative processes other than those utilized for laser operation.