High power solid state laser

In a solid state laser of the type characterized by a solid member of lasant material having a pair of opposed major faces between which optical lasant energy generated within said member is caused to be internally reflected in a zig-zag path, the improvement comprising:

• optical pumping means for passing optical pumping radiation through a selected region of at least one of said major faces and into said member for optically pumping said lasant material;
• and
• moving means for imparting cyclical relative motion between said member of lasant material and the selected region of said member which is illuminated by said optical pumping radiation so as to distribute the heat generated in said member of lasant material by said optical pumping radiation approximately evenly throughout the member of lasant material, whereby thermally induced depolarization and focusing effects are reduced in use.