Abstract: An array of gradient refractive index lenses designed to produce an erect image of an extended object. The lenses are supported in a matrix of light-absorbing cladding glass for stray light control.

Abstract: A method for producing an optical waveguide by melt-drawing a transparent glass rod which has been produced by collapsing a porous glass rod after being doped with a dopant material by depositing said material on the surface of the micro pores in order to enhance the refractive index of the collapsed glass rod, wherein a waveguide having higher mechanical strength and lower transmission is attained by drawing said glass rod at a temperature very close to the melting point of the outermost portion of the fiber without causing any overmelting or bubbling in the core portion, said drawing being facilitates by matching the viscosity and characteristics of the outermost lower-refractive-index portion to those of the central higher-refractive-index portion.

Abstract: In the operation of a pressing plunger for forming a parison from a gob of molten glass, it is important that the plunger be moved into the gob which is retained in the parison mold, with a fairly rapid motion and also be capable of being withdrawn from the formed parison as rapidly as possible. One other consideration is that it not be pressing the glass at the final portion of its travel at a very high force. By providing a large piston for moving the plunger into and out of pressing position, it is possible to move the plunger at a relatively high velocity with high operating pressure. A small piston is provided within the larger piston and by reason of having a substantially smaller surface area, with the smaller piston being connected to the plunger, a lower force is applied to the plunger. The plunger with its piston is moved by the larger piston to the fullest extent of the large piston's travel, and the smaller piston to which the plunger is attached is free to move relative to the large piston.