Abstract: A high frequency laser for generating a coherent collimated beam in the ultraviolet to x-ray range using a high energy charged particle beam is provided. The laser utilizes an undulator which in one embodiment is a solid state superlattice composed of alternating layers of two materials have slightly different lattice spacing to provide strain modulation. A beam of charged particles is injected into the undulator to stimulate emission at short wavelengths in ultraviolet to hard x-ray range. The feedback required for lasing action is provided by Bragg diffraction involving the basic crystal lattice or other mirror device such as a superlattice mirror. In another embodiment, a dynamic undulator is used comprising infrared electromagnetic radiation. High energy Lithium ions are injected into the undulator resulting in stimulation of high frequency radiation. The feedback is provided by a superlattice mirror.