High performance dye laser and flow channel therefor

A flow channel for liquid fluent laser material of a laser comprising:

• an input plenum positioned to receive a liquid fluent laser material;
• a pair of optically transmissive windows in facing relationship to each other with generally parallel inner surfaces;
• means for applying excitation radiation through said first and second windows;
• a conduit for directing a continuous flow of fluent material from said input plenum to the region between said windows and transverse thereto, said conduit having walls bordering said continuous flow which provide a generally decreasing cross-sectional area between said input plenum and said windows;
• the applied radiation producing heat of said conduit walls from radiation from the fluent material in the region between said windows;
• means for abating temperature effects to reduce refractive index gradients in fluent laser material received by said input plenum within the region between said windows;
• said means comprising:
• cooling ducts associated with said conduit and located adjacent and in thermal contact with said conduit walls at positions bordering said conduit flow at least upstream of and away from the region between said windows;
• said ducts thus operative to cool said conduit walls in the region of said walls adjacent said windows and thus exposed to said heating by said radiation from the region between said windows and thereby to reduce temperature gradients in fluent laser material flowing past said windows;
• an output plenum positioned to accept fluent laser material after flowing between said windows along an extension of said conduit;
• means for exhausting fluent laser material from said output plenum.