Raman beam combining for laser brightness enhancement

An apparatus, comprising

• a pulsed fiber seed laser for providing a pulsed seed beam having a first pulse peak power within a range from about 100 W to about 100 KW;
• a plurality of pulsed fiber pump lasers for providing pulsed pump beams, wherein each pump beam comprises a second pulse peak power within a range from about 10 KW to about 100 MW;
• a first stimulated Raman scattering (SRS) crystal consisting essentially of crystalline material and having a shape comprising a first face at a first end of said crystal, a second face at a second end of said crystal and an outer wall extending from said first face to said second face, wherein said first face is positioned to receive said seed beam and said pump beams;
• a reflective coating in direct contact with said outer wall, wherein said apparatus is configured such that said pump beams will propagate through said first face into said crystal and will then be confined within said crystal by reflecting a plurality of times from said reflective coating, wherein said pump beams will then propagate through said second face and out of said crystal wherein said apparatus is configured such that said seed beam will propagate through said first face in to said crystal and will then propagate within said crystal without undergoing any internal reflections, wherein said seed beam will then propagate through said second face and out of said crystal;
• and
• means for precisely timing said pulsed seed beam and said pulsed pump beams so that they are timed to be co-incident in time on said crystal.