a weldable workpiece prepared by depositing on a surface of the workpiece , an absorber dye possessing strong absorption and a high extinction coefficient . the dye is deposited at a uniform density and thereby has the capacity to convert inbound radiant energy over about 0 . 1 j per square millimeter into thermal energy via vibronic relaxation and exothermic decomposition . in optical applications , the workpiece forms welds of high photopic and optical transmission . a method for preprocessing the workpiece describes steps for selecting polymers , dyes and vehicles .