Abstract: An optical fiber bundle that has better ultraviolet resistance characteristics at a wavelength range of 150 to 250 nm and that can be readily and cheaply manufactured with no risk of, for example, explosion during manufacturing and its manufacturing method are provided. In the optical fiber bundle, optical fibers including a core mainly containing silica glass and a cladding containing silica glass and fluorine are bundled and accommodated in a container. This container has optically transparent ends, accommodates hydrogen or deuterium as well as the optical fibers, and is sealed. The capacity of the container is 10 times or less as large as the volume of glass of the optical fibers.

Abstract: An optical fiber bundle that has better ultraviolet resistance characteristics at a wavelength range of 150 to 250 nm and that can be readily and cheaply manufactured with no risk of, for example, explosion during manufacturing and its manufacturing method are provided. In the optical fiber bundle, optical fibers including a core mainly containing silica glass and a cladding containing silica glass and fluorine are bundled and accommodated in a container. This container has optically transparent ends, accommodates hydrogen or deuterium as well as the optical fibers, and is sealed. The capacity of the container is 10 times or less as large as the volume of glass of the optical fibers.

Abstract: Affords GaN crystal substrates that can reduce the occurring of cracks and fractures in the GaN crystal substrates when the semiconductor devices are manufactured, semiconductor devices including them, methods of manufacturing the semiconductor devices, and methods of identifying the GaN crystal substrates. A gallium nitride crystal substrate has a surface area of 10 cm2 or more. The difference between the maximum and the minimum of Raman shifts corresponding to the E2H phonon mode in a region except for a region from the outer periphery in the surface of the gallium nitride crystal substrate to a line 5 mm radially inward from the outer periphery of the surface is 0.5 cm?1 or less. And also affords semiconductor devices including them, methods of manufacturing the semiconductor devices, and methods of identifying the GaN crystal substrates.

Abstract: An optical fiber bundle that has better ultraviolet resistance characteristics at a wavelength range of 150 to 250 nm and that can be readily and cheaply manufactured with no risk of, for example, explosion during manufacturing and its manufacturing method are provided. In the optical fiber bundle, optical fibers including a core mainly containing silica glass and a cladding containing silica glass and fluorine are bundled and accommodated in a container. This container has optically transparent ends, accommodates hydrogen or deuterium as well as the optical fibers, and is sealed. The capacity of the container is 10 times or less as large as the volume of glass of the optical fibers.