Abstract: An apparatus and method of manufacturing optical waveguides that comprises non-optically measuring the average temperature of a moving optical waveguide fiber as it exits a heated draw furnace using a temperature device. The device comprises an enclosed chamber that has a plurality of differential thermopiles secured to the inside surface, and a cooling system that substantially maintains a reference surface temperature of one end of each of the thermopiles. Each of the thermopiles are serially interconnected, whereby, in response to a maximum amount of radiant energy absorbed, the thermopiles generate an output signal. The output signal is substantially proportional to the maximum amount of radiant energy absorbed by the thermopiles, which in turn is substantially proportional to the fourth power of the average temperature of the moving optical waveguide fiber within the chamber.

Abstract: Methods, apparatus and precursors for producing substantially water-free silica soot, preforms and glass. The methods and apparatus make substantially water-free fused silica preforms or glass by removing water as a reaction product, removing water from the atmosphere, removing water from the transport process, or combinations thereof. In a first embodiment, substantially water-free soot, preforms or glass are achieved by using a hydrogen-free fuel, such as carbon monoxide, in the deposition process. In another embodiment, a soot producing burner has parameters that enable operation on a substantially hydrogen-free fuel. End burners, which minimize water production, are also described. Such water-free methods are useful in depositing fluorine-doped soot because of the low water present and the efficiency in which fluorine is incorporated. In another embodiment, glassy barrier layer methods and apparatus are described for minimizing dopant migration, especially fluorine.

Abstract: A thin sensor for heat flux and temperature, designed for adhesive attachment to a surface, is manufactured on a flexible insulated metallic substrate, using conductive and dielectric inks. The sensor exhibits a combination of high sensitivity for heat flux and low resistance to the flow of heat. These characteristics enable it to measure heat flux at surface boundaries with improved accuracy over conventional heat flux transducers (HFT's) because the temperature drop produced by the sensor is very small. The high sensitivity of the sensor makes it ideal for measuring heat flow through insulating materials, and well adapted to instrumenting heat flow in buildings, detecting fires at an early stage, or remotely measuring the temperature of string and web products in industrial processing.