Optically pumped laser amplifiers are disclosed. One type of such amplifier utilizes an excitable medium, the atoms, ions or molecules of said medium having well defined energy states including a lowest state, a lower state above said lowest state, and a higher state above said lower state, and a bright pumping light source composed of a radiative substance different from such medium which radiative substance emits energy in a spectral range which can be absorbed by such medium, and wherein the major portion of the energy absorbed by such medium causes transitions of the atoms, ions, or molecules thereof to populate the higher state. Another type of such amplifier utilizes a medium of atoms, ions, or molecules, some of which have broad bands of energy levels corresponding to a broad band of absorption transitions and energy levels corresponding to at least one fluorescent emission transition, the upper energy levels of said broad bands being above the upper level of said fluorescent emission transition, and wherein some of the upper energy levels above the upper level of said fluorescent emission transition are rapidly quenched via non-radiating transitions to the upper level of said fluorescent emission transition. In a preferred embodiment of the latter amplifier, the lower energy level corresponding to the fluorescent emission transition is relaxed by non-radiating transitions.