摘要:
A porous layer is formed by depositing a silica glass particle around a core rod. The porous layer is dehydrated. The dehydrated porous layer is sintered under a decreased pressure until the dehydrated porous layer becomes a translucent glass layer containing a closed pore. The translucent glass layer is vitrified under an ambient atmosphere including an inert gas other than a helium gas.
摘要:
Drawing methods and drawing furnaces for drawing an optical fiber with small non-circularity by simple drawing system are provided. An optical fiber preform is received into a muffle tube and heated by a primary heater placed to surround the muffle tube. The optical fiber preform is heated such that a starting position of a meniscus portion is higher in its position than the top of the primary heater, wherein the meniscus portion is created at the bottom portion of the optical fiber preform.
摘要:
The linear semiconductor substrate 1 or 2 of the present invention comprises at least one desired thin film 4 formed on a linear substrate 3 having a length ten or more times greater than a width, thickness, or diameter of the linear substrate itself. Adopting semiconductor as the thin film 4 forms a linear semiconductor thin film. The linear semiconductor substrate 1 or 2 of the present invention is produced by utilizing a fiber-drawing technique which is a fabricating technique of optical fibers.
摘要:
Drawing methods and drawing furnaces for drawing an optical fiber with small non-circularity by simple drawing system are provided. An optical fiber preform is received into a muffle tube and heated by a primary heater placed to surround the muffle tube. The optical fiber preform is heated such that a starting position of a meniscus portion is higher in its position than the top of the primary heater, wherein the meniscus portion is created at the bottom portion of the optical fiber preform.
摘要:
A glass substrate for a magnetic disk satisfies Ra1≦0.8 [nm], 0 [nm]≦Ra1−Ra2≦0.2 [nm], Wa1≦0.6 [nm], and 0 [nm]≦Wa2−Wa1≦0.2 [nm]. Ra1 is an average surface roughness of a first annular area between 1 mm and 3 mm outward from an inner periphery of a main surface of the glass substrate, Ra2 is an average surface roughness of a second annular area between 1 mm and 3 mm inward from an outer periphery of the main surface, Wa1 is an average waviness of the first area in a circumferential direction of the glass substrate having a cycle of 300 μm to 5 mm, and Wa2 is an average waviness of the second area in the circumferential direction having a cycle of 300 μm to 5 mm.