Abstract: A furnace for fining molten glass is provided in which glass flows in a substantially vertical direction prior to exiting the furnace. As it flows vertically, the glass is allowed to cool. This cooling, in turn, allows the glass to be removed from the furnace through a narrow passageway without producing excessive wear of the passageway. Preferably, vertical flow of the molten glass at the exit end of the furnace is produced across the furnace's full width. In this way, the molten glass does not stagnate within the furnace and undesirable scums on the top surface of the glass are avoided. In certain preferred embodiments, the vertical flow is achieved by a trough which has sloped sides and which connects with and extends downward from the bottom surface of the furnace.

Abstract: A non-contact system for monitoring the tension in an optical waveguide fiber during drawing is provided. The system comprises: (a) means for sensing the motion of the fiber in a direction transverse to the direction in which the fiber is moving; (b) means for analyzing the sensed motion to determine at least one frequency component thereof; and (c) means for monitoring the frequency component so determined so as to monitor the tension in the fiber.

Abstract: Methods are provided for reducing the water content of optical waveguide fibers produced from blanks having a centerline aperture and having compositions which prevent cooling of the blank to room temperature between consolidation and drawing. In accordance with certain aspects of the invention, the water content is reduced by storing the blanks at as low a temperature as possible, preferably below about 550.degree. C. In accordance with other aspects, the water content is reduced by filling the apertures of the blanks with an inert atmosphere during storage.

Abstract: A split recoating mold for use in recoating optical waveguide fibers with a UV-curable resin is provided wherein: (1) the mold, when closed, forms a cavity for receiving the portion of the fiber which is to be recoated, the cross-sectional size and shape of the cavity being essentially equal to the cross-sectional size and shape of the original fiber; (2) the mold includes an injection port for introducing a UV-curable resin into the cavity; and (3) the mold includes means for introducing ultraviolet light into the cavity so that resin located in regions of the cavity remote from the injection port will cure prior to resin located in regions of the cavity near the injection port.