Apparatus for end-pumping of a solid-state laser with a source of high optical brightness. A stack of diode laser bars are excited, and each bar emits a light beam of a selected pump wavelength in a chosen direction. The light beam output of the diode bar stack is divided into a plurality of smaller, approximately rectangular light beams, which serve as extended light sources, by a plurality of mirrors that are positioned to receive one or more of these smaller beams and redirect such beams onto first, light-receiving ends of one or more optical fibers. Light collection optics receive the beams issuing from the mirrors and focus these beams onto a light-receiving end of an optical fiber with beam convergence angles that are appropriate for the numerical aperture of that fiber. Second ends of the optical fibers are optionally positioned so that a light beam emitted from the second end of a fiber is received by a laser gain material in a laser cavity and propagates along a common optical path within the laser cavity, thereby pumping the laser gain material.