is either heated to a temperature that causes a flowing state thereof or is treated exothermically to cause such flowing state in a well known manner is injected through an injection gate 16 while the atmosphere in the formed cavity is removed through a vent 17 once the cavity is completely filled with the polymer the polymer is cooled at a controlled rate in order to prevent excessive shrinkage of the window and in order to maintain the clarity of the polymer once the pad has been removed from the mold fixture further treatment of the window if required may be performed in order to remove any irregularities formed via the injection gate 16 and vent 17 the mold fixture preferably removes any irregularities during the injection process by closing the gate and vent holes at a specific time thereby making the polymer planar with the cavity vent 17 may not be required for a more porous pad where the atmosphere in the cavity is able to evacuate through the material of the polishing pad itself the polymer may be amorphous semi crystalline crystalline or elastomeric material laser transparent polymers that may be used but not limited to are clear polypropylene pp acrylonitrile butadiene styrene abs polycarbonate pc acrylic styrene acrylonitrile asa polyphenylene ether ppe and polyetherimide pei the integrity of the window of the polishing pad is formed by diffusion of the.