A positive pressure gradient is maintained across an open access port of an interface chamber such as a load lock chamber which provides an interface between a low pressure chamber such as a transfer or buffer chamber, and a high pressure area such as a staging area or factory interface area. The centrifuged product is directed through a valve in the bottom of the vacuum chamber to a sluice structure, and subsequently is subjected to atmospheric pressure. A taper formed in the second waveguide facilitates communication of light between waveguides. Alternatively, the mounting structures are formed by molding before being attached to the clad metal shell by an adhesive. In yet another aspect, a gas nozzle located downstream from the applicator nozzle sprays gas on the coating curtain in order to help apply the coating mix to the surface of the web. The laser beam shaper includes a lens having two aspheric surfaces.