Methods and apparatus for producing fibers from igneous rock, including basalt include heating igneous rock by electrical conductive coils to achieve an homogenous melt and forming homogenous fibers from the melt.

Methods and apparatus for producing fibers from igneous rock, including basalt include heating igneous rock by electrical conductive coils to achieve an homogenous melt and forming homogenous fibers from the melt.

Polarizing optical devices described herein, and polarizing optical devices resulting from methods described herein, can be small and can have high heat tolerance. Wires of wire grid polarizers can be attached directly to prisms of the polarizing optical devices, allowing for small size. Multiple polarizing optical devices can be attached by adhesive-free bonding techniques, allowing high heat tolerance.

Polarizing optical devices described herein, and polarizing optical devices resulting from methods described herein, can be small and can have high heat tolerance. Wires of wire grid polarizers can be attached directly to prisms of the polarizing optical devices, allowing for small size. Multiple polarizing optical devices can be attached by adhesive-free bonding techniques, allowing high heat tolerance.

An automated large outside diameter preform tipping process. A zone of the preform is heated inside a furnace and softened. The preform tip is shaped and the process is controlled by the movement of the glass above and below the heating zone and by sensing the weight of the lower part of the preform, which in effect is a measure of the viscosity of the softened material. Once the correct viscosity is reached, the bottom holder is moved away from the top holder with a non-linear, accelerated velocity profile (derived from the FEM simulation of glass flow) which is precisely programmed and controlled so that the preform tip is optimally shaped (usually short and sharp tipped) with minimum waste and waveguide distortion when drawn into a fiber. The same concept of the non-linear, accelerated velocity profile can also be applied to other tipping processes such as horizontal preform tipping processes.

An automated large outside diameter preform tipping process. A zone of the preform is heated inside a furnace and softened. The preform tip is shaped and the process is controlled by the movement of the glass above and below the heating zone and by sensing the weight of the lower part of the preform, which in effect is a measure of the viscosity of the softened material. Once the correct viscosity is reached, the bottom holder is moved away from the top holder with a non-linear, accelerated velocity profile (derived from the FEM simulation of glass flow) which is precisely programmed and controlled so that the preform tip is optimally shaped (usually short and sharp tipped) with minimum waste and waveguide distortion when drawn into a fiber. The same concept of the non-linear, accelerated velocity profile can also be applied to other tipping processes such as horizontal preform tipping processes.

Provided is a method for manufacturing a glass fiber strand in which a glass fiber strand is formed by bundling a plurality of glass fiber filaments comprising molten glass drawn out from a nozzle, wherein said method for manufacturing a glass fiber strand is capable of detecting breakage of the glass fiber filaments in a more reliable manner. This method comprises: an image capturing step (STEP-1) for generating a plurality of items of image data by continuously capturing images of a plurality of glass fiber filaments f; an image processing step (STEP-2) for extracting, from the image data, a high luminance object 100 having a luminance of a prescribed value or more; and a breakage detection step (STEP-3) for detecting that a glass fiber filament f has broken on the basis of the results of the image processing in the image processing step. In the breakage detection step, the presence of a change in the position of a high luminance object 100 is detected on the basis of the plurality of items of the image data, and it is determined that the glass fiber filament f has broken when a change in the position of a high luminance object 100 is detected.

Provided is a method for manufacturing a glass fiber strand in which a glass fiber strand is formed by bundling a plurality of glass fiber filaments comprising molten glass drawn out from a nozzle, wherein said method for manufacturing a glass fiber strand is capable of detecting breakage of the glass fiber filaments in a more reliable manner. This method comprises: an image capturing step (STEP-1) for generating a plurality of items of image data by continuously capturing images of a plurality of glass fiber filaments f; an image processing step (STEP-2) for extracting, from the image data, a high luminance object 100 having a luminance of a prescribed value or more; and a breakage detection step (STEP-3) for detecting that a glass fiber filament f has broken on the basis of the results of the image processing in the image processing step. In the breakage detection step, the presence of a change in the position of a high luminance object 100 is detected on the basis of the plurality of items of the image data, and it is determined that the glass fiber filament f has broken when a change in the position of a high luminance object 100 is detected.

A method of controlling the temperature of an optical fiber is provided that includes the steps of: providing an energy transfer member configured to accept or provide thermal energy, the energy transfer member defines an energy transfer surface; passing an optical fiber proximate the energy transfer member such that a gap is defined between the optical fiber and the energy transfer surface; and transferring thermal energy between the optical fiber and the energy transfer member via conduction across the gap.

A method of controlling the temperature of an optical fiber is provided that includes the steps of: providing an energy transfer member configured to accept or provide thermal energy, the energy transfer member defines an energy transfer surface; passing an optical fiber proximate the energy transfer member such that a gap is defined between the optical fiber and the energy transfer surface; and transferring thermal energy between the optical fiber and the energy transfer member via conduction across the gap.