A laser system comprising: a plurality of laser resonators (10A, 10B, 10C, 10D), each resonator being operable to discharge an input laser beam; a relay assembly including for each input laser beam a respective curved reflective surface (12A, 12B, 12C, 12D) that is configured to redirect the respective input laser beam, and to reduce a beam size of the redirected beam; a galvo including a curved reflective surface that is configured to be movable so as to receive each redirected beam, and to output a combined laser beam at power level greater than a power level of each laser input beam; and a coupling assembly that is configured to reduce spherical aberrations in the combined laser beam, and to direct the combined laser beam into an optical fiber, wherein the combined laser beam has a maximum beam parameter product lower than a minimum beam parameter product of the optical fiber, wherein each curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly has a first curvature radius, the curved reflective surface of the galvo has a second curvature radius, and the first and second curvatures are different, wherein: each input laser beam is discharged along a beam path comprising: (i) a first distance extending from one resonator of the plurality of laser resonators (10A, 10B, 10C, 10D) to the respective curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly; (ii) a second distance extending from the respective curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly to the curved reflective surface of the galvo; and (iii) a third distance extending from the reflective surface of the galvo to the optical fiber; the first and second curvature radii are sized relative to the first, second, and third distances; and the first distance is approximately equal to the second distance, and the third distance is greater than the sum of the first and second distances, and the first curvature radius is approximately one third the second curvature radius. a plurality of laser resonators (10A, 10B, 10C, 10D), each resonator being operable to discharge an input laser beam; a relay assembly including for each input laser beam a respective curved reflective surface (12A, 12B, 12C, 12D) that is configured to redirect the respective input laser beam, and to reduce a beam size of the redirected beam; a galvo including a curved reflective surface that is configured to be movable so as to receive each redirected beam, and to output a combined laser beam at power level greater than a power level of each laser input beam; and a coupling assembly that is configured to reduce spherical aberrations in the combined laser beam, and to direct the combined laser beam into an optical fiber, wherein the combined laser beam has a maximum beam parameter product lower than a minimum beam parameter product of the optical fiber, wherein each curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly has a first curvature radius, the curved reflective surface of the galvo has a second curvature radius, and the first and second curvatures are different, wherein: each input laser beam is discharged along a beam path comprising: (i) a first distance extending from one resonator of the plurality of laser resonators (10A, 10B, 10C, 10D) to the respective curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly; (ii) a second distance extending from the respective curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly to the curved reflective surface of the galvo; and (iii) a third distance extending from the reflective surface of the galvo to the optical fiber; the first and second curvature radii are sized relative to the first, second, and third distances; and the first distance is approximately equal to the second distance, and the third distance is greater than the sum of the first and second distances, and the first curvature radius is approximately one third the second curvature radius. each input laser beam is discharged along a beam path comprising: (i) a first distance extending from one resonator of the plurality of laser resonators (10A, 10B, 10C, 10D) to the respective curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly; (ii) a second distance extending from the respective curved reflective surface (12A, 12B, 12C, 12D) of the relay assembly to the curved reflective surface of the galvo; and (iii) a third distance extending from the reflective surface of the galvo to the optical fiber; the first and second curvature radii are sized relative to the first, second, and third distances; and the first distance is approximately equal to the second distance, and the third distance is greater than the sum of the first and second distances, and the first curvature radius is approximately one third the second curvature radius.