摘要:
A 1.55 µm band dispersion shifted optical fiber is provided which has a low loss and low dispersion slope. A core region "a" is heavily doped with GeO 2 . A core region "b" is composed of pure SiO 2 glass. A cladding section 3 is arranged around the core region. The cladding section 3 has a lot of holes 4 extending in the longitudinal direction of the optical fiber. The holes 4 of the cladding section 3 are not located at random, but have a honeycomb structure composed of regular hexagons which have a side length of A, and serve as a primitive lattice. The center of the core region 1 and 2 has a region 3 having a refractive index higher than that of the periphery of the core section 1 and 2. The core region 1 and 2 has the refractive index distribution in which the group velocity dispersion at the operation wavelength of the region 3 becomes the normal dispersion.
摘要:
A rotation shaft seal provided with a rubber sealing portion (5) which contacts a surface of a rotation shaft (20) and an outer case (1) to which the rubber sealing portion (5) is unitedly fixed. The outer case (1) has an inner brim portion (2) on an inner end portion on a sealed fluid side (C). The inner brim portion (2) is covered by the rubber sealing portion (5). A sliding portion (23) is disposed on an axis-orthogonal face (P 0 ) including the inner brim portion (2).
摘要:
A polarization-maintaining optical fiber and absolutely single-polarization optical fiber are provided which enable long distance transmission maintaining a polarization state of signal light. The polarization-maintaining optical fiber includes a core (11), photonic crystal cladding (12) and jacket (13). The photonic crystal cladding (12) is divided into four segments (12a, 12b, 12c and 12d) by broken lines from the center to the periphery. Among a plurality of grating holes in a pair of segments (12a and 12c) opposed to each other with respect to the core (11), the diameter (d2) of grating holes (14a and 14c) close to the core (11) is greater than the diameter (d1) of grating holes in another pair of segments (12b and 12d) opposed with each other, and than a grating constant (Λ).
摘要:
A fit-holding groove is formed by notching the outer periphery of a door element to be fitted to close a container body. A sealing element interposed between the container body and door element is composed of an endless portion to be fitted into the fit-holding groove, a protruding part projected from the peripheral corner of the endless portion, obliquely and outwardly with respect to the open front of the container body, forming a substantially acute angle between itself and the contact surface of the open front of the container body and a pair of fitting ribs projectively formed on the obverse surface of the endless portion so as to be fitted in contact with the compartmentalized inner wall of the fit-holding portion.
摘要:
A method for producing a wave absorber, which method includes rubbing a mixture of a solidifiable fluid binder and a particulate dielectric loss material on a substrate and solidifying the binder, thereby to laminate a wave absorptive layer on the substrate, and a wave absorber produced by this production method are provided. According to the production method of the present invention, a structure including a dielectric loss material and a binder admixed most preferably for wave absorption can be formed easily into a long sheet or a long belt-like wave absorber.
摘要:
A rotating shaft seal provided with a seal element (E), arranged between a housing (31) and a rotation shaft (32), which contacts the rotation shaft (32), and a seal member (5) made of rubber having a lip end portion (13b), disposed on a fluid storing chamber (33) side to the seal element (E), which contacts the rotation shaft (32), comprising a supporting metal (12) for supporting a rear face of the seal member (5) of rubber.
摘要:
An optical fiber coupler for optical fiber amplifier use in the field of optical communications is provided. The optical fiber coupler comprises: a rare earth-doped fiber as an optical amplifying element; a quasi rare earth-doped fiber for entrance of input signal light; a fused-stretch fiber portion as a multiplexing element which connects a part of the rare earth-doped fiber and a parts the quasi rare earth-doped fiber, wherein the fused-stretch fiber portion formed by stretched a fused mixture of parts of the rare earth-doped fiber and the quasi rare earth-doped fiber; and a single mode fiber which is jointed at a fused joint portion to another shortened rare earth-doped fiber connected to the fused-stretch fiber portion on a side connected by the quasi rare earth-doped fiber. The quasi rare earth-doped fiber has substantially equal propagation constant to the rare earth-doped fiber without substantially containing rare earth elements. The optical fiber coupler is fabricated by the steps of jointing a single mode fiber with a rare earth-doped fiber by fusing abutted end faces of both fibers to form a combined fiber; and fusing parallel contact parts of a quasi rare earth-doped fiber and of the rare earth-doped fiber of the combined fiber and then elongating the fused parts in a desired diameter to form a fused-stretch fiber portion.
摘要:
A GaN group crystal base member comprising a base substrate, a mask layer partially covering the surface of said base substrate to give a masked region, and a GaN group crystal layer grown thereon to cover the mask layer, which is partially in direct contact with the non-masked region of the base substrate, use thereof for a semiconductor element, manufacturing methods thereof and a method for controlling a dislocation line. The manufacturing method of the present invention is capable of making a part in the GaN group crystal layer, which is above a masked region or non-masked region, have a low dislocation density.