Abstract: An objects detecting method for a vacuum processing apparatus equipped with: a processing unit including a vacuum container having therein a processing chamber in which a wafer is processed, and an exhaust pump that exhausts gas in the processing chamber; a vacuum transfer unit including a transfer chamber in which the wafer is transferred; and a connection pipe including a passage through which the wafer can be transferred between the processing chamber and the transfer chamber, includes: an objects collecting process of increasing an internal pressure of the transfer chamber to be higher than an internal pressure of the processing chamber to generate a gas flow in the passage from the transfer chamber toward the processing chamber, transferring the wafer to a position straddling the transfer chamber, the passage, and the processing chamber, and holding the wafer for a predetermined time; and an objects detecting process of detecting objects adhering to a surface of the wafer.

Abstract: An optical fiber (10) includes: a core (11); a first cladding (12) surrounding the core (11) and having a lower refractive index than the core (11); and a second cladding (13) surrounding the first cladding (12) and having a lower refractive index than the first cladding (12). The first cladding (12) is doped with light attenuating dopant so that a concentration of the light attenuating dopant in the first cladding (12) increases from an inner surface of the first cladding (12) toward an outer surface of the first cladding (12).

Abstract: A graded index multimode optical fiber (10) includes: a core (11) having an outside diameter of 45-65 ?m; a first cladding (12) surrounding the core (11); a second cladding (13) surrounding the first cladding (12) and made of a material having a lower refractive index than the first cladding (12); and a third cladding (14) surrounding the second cladding (13) and made of a material having a higher refractive index than the second cladding (13). The ratio of the outside diameter of the first cladding (12) to the outside diameter of the core (11) is 1.15-1.25.

Abstract: An optical fiber includes a core (1a) having an oblong rectangular or square cross section and made of quartz, a cladding (2) surrounding the core (1a), having a circular outer cross-sectional shape, having a lower refractive index than the core (1a), and made of resin, and a support layer (3) surrounding the cladding (2) and made of quartz.

Abstract: An optical fiber includes: a core (1) having an outer diameter (D1) of greater than or equal to 8.2 ?m and less than or equal to 10.2 ?m; a first cladding (2) surrounding the core (1) and having an outer diameter (D2) of greater than or equal to 30 ?m and less than or equal to 45 ?m; a second cladding (3) surrounding the first cladding (2) and having a thickness (T) of greater than or equal to 7.4 ?m; and a support layer (4) surrounding the second cladding (3). The relative refractive index difference which is the ratio of the difference between the refractive index of the support layer (4) and that of the second cladding (3) to the refractive index of the support layer (4) is greater than or equal to 0.5%.

Abstract: An optical fiber includes a core (1a) having an oblong rectangular or square cross section and made of quartz, and a cladding (2) surrounding the core (1a), having a circular outer cross-sectional shape, and made of resin.

Abstract: An optical fiber (10) includes: a core (11); a first cladding (12) surrounding the core (11) and having a lower refractive index than the core (11); and a second cladding (13) surrounding the first cladding (12) and having a lower refractive index than the first cladding (12). The first cladding (12) is doped with light attenuating dopant so that a concentration of the light attenuating dopant in the first cladding (12) increases from an inner surface of the first cladding (12) toward an outer surface of the first cladding (12).

Abstract: An optical fiber includes a core (1a) having an oblong rectangular or square cross section and made of quartz, a cladding (2) surrounding the core (1a), having a circular outer cross-sectional shape, having a lower refractive index than the core (1a), and made of resin, and a support layer (3) surrounding the cladding (2) and made of quartz.

Abstract: A graded index multimode optical fiber (10) includes: a core (11) having an outside diameter of 45-65 ?m; a first cladding (12) surrounding the core (11); a second cladding (13) surrounding the first cladding (12) and made of a material having a lower refractive index than the first cladding (12); and a third cladding (14) surrounding the second cladding (13) and made of a material having a higher refractive index than the second cladding (13). The ratio of the outside diameter of the first cladding (12) to the outside diameter of the core (11) is 1.15-1.25.

Abstract: A method for manufacturing a photonic crystal fiber including arranging a spacer formed of two or more spacer parts in a support tube such that the inner wall surface of the support tube has a substantially regular polygonal cross-sectional shape which allows closest packing of a core rod and a plurality of capillaries or the capillaries only; and forming a preform by packing in a support tube the core rod for forming a solid core and the capillaries for forming a cladding, or by providing a core space for forming a hollow core in a support tube and packing in the support tube a plurality of capillaries for forming the cladding; and drawing the preform into a fiber under heating.

Abstract: An optical fiber includes a core (1a) having an oblong rectangular or square cross section and made of quartz, and a cladding (2) surrounding the core (1a), having a circular outer cross-sectional shape, and made of resin.

Abstract: An optical fiber includes: a core (1) having an outer diameter (D1) of greater than or equal to 8.2 ?m and less than or equal to 10.2 ?m; a first cladding (2) surrounding the core (1) and having an outer diameter (D2) of greater than or equal to 30 ?m and less than or equal to 45 ?m; a second cladding (3) surrounding the first cladding (2) and having a thickness (T) of greater than or equal to 7.4 ?m; and a support layer (4) surrounding the second cladding (3). The relative refractive index difference which is the ratio of the difference between the refractive index of the support layer (4) and that of the second cladding (3) to the refractive index of the support layer (4) is greater than or equal to 0.5%.

Abstract: A cladding 12 of a photonic crystal fiber 10 has first to fourth air hole layers 15 to 18 formed around a core 11 one after another in the radial direction of the fiber. In forming the fiber, assuming that air holes 12a constituting the first air hole layer 15 have a diameter d1, at least one of air holes 12a constituting the second to fourth air hole layers 16 to 18 is formed in a smaller diameter d2 than the diameter d1.

Abstract: A method for manufacturing a photonic crystal fiber (20) including the steps of: arranging a spacer (4) formed of two or more spacer parts in a support tube (3) such that the inner wall surface of the support tube (3) has a substantially regular polygonal cross-sectional shape which allows closest packing of a core rod (2) and a plurality of capillaries (1) or the capillaries (1) only; and forming a preform (15) by packing in a support tube (3) the core rod (2) for forming a solid core and the capillaries (1) for forming a cladding, or by providing a core space for forming a hollow core in a support tube (3) and packing in the support tube (3) a plurality of capillaries (1) for forming the cladding; and drawing the preform (15) into a fiber under heating.