摘要:
A polarization-maintaining photonic crystal fiber 10 includes six thin holes 4a and 4b adjacent to a core 1. Among these holes 4a and 4b, a pair of holes 4b at opposite sides of the core 1 have a diameter greater than that of the other four thin holes 4a, and therefore, the polarization-maintaining photonic crystal fiber 10 has polarization-maintaining ability. An overclad layer 3 exists around the clad layer 2 which includes a large number of thin holes 4a and 4b around the core 1. The overclad layer 3 includes a pair of marking portions 5 at opposite sides of the core 1. The marking portions 5 are holes which can be seen at positions different from the clad layer 2 when the fiber 10 is viewed from a position right above the fiber 10 in the drawing. In this way, the direction of the polarization plane of the polarization-maintaining photonic crystal fiber 10 is identified.
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 GeO2 . A core region “b” is composed of pure SiO2 glass. A cladding section is arranged around the core region. The cladding section has a lot of holes extending in the longitudinal direction of the optical fiber. The holes of the cladding section are not located at random, but have a honeycomb structure composed of regular hexagons which have a side length of Λ, and serve as a primitive lattice. The center of the core section has a region having a refractive index higher than that of the periphery of the core section. The core section has the refractive index distribution in which the group velocity dispersion at the operation wavelength of the region becomes the normal dispersion.
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, photonic crystal cladding, and jacket. The photonic crystal cladding is divided into four segments by broken lines from the center to the periphery. Among a plurality of grating holes in a pair of segments opposed to each other with respect to the core, the diameter of grating holes close to the core is greater than the diameter of grating holes in another pair of segments opposed with each other, and than a grating constant.
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 GeO2 . A core region “b” is composed of pure SiO2 glass. A cladding section is arranged around the core region. The cladding section has a lot of holes extending in the longitudinal direction of the optical fiber. The holes of the cladding section are not located at random, but have a honeycomb structure composed of regular hexagons which have a side length of Λ, and serve as a primitive lattice. The center of the core section has a region having a refractive index higher than that of the periphery of the core section. The core section has the refractive index distribution in which the group velocity dispersion at the operation wavelength of the region becomes the normal dispersion.
摘要:
An optical fiber connection structure which reduces MPI in the use of an optical fiber with a bend resistance improved by forming holes in the fiber, and a single-mode fiber which reduces MPI are provided. A second cladding portion of a second single-mode fiber 20 includes holes 28, and thus, the second single-mode fiber 20 has low bending loss. A portion of the second single-mode fiber 20 connected to a first single-mode fiber 10a is made solid by filling corresponding portions of the holes 28 over the length L0, and light in a mode LP11 is significantly attenuated in this portion, thereby reducing MPI.
摘要:
A collimator, a radiological imaging apparatus and a nuclear medicine diagnosis apparatus which are able to improve the sensitivity are provided. The radiological imaging apparatus has a collimator 11 disposed to oppose a radiological detection device 12 and having through-holes 11a for passing to the radiological detection device 12 gamma rays in a specified direction out of those radiated from an object to be examined. The collimator 11 is produced by mutually coupling a plurality of metal tubular members 11A each having the through-hole 11a with the help of a bonding agent S in alignment with a plurality of detectors 12a constituting the radiological detection device 12.
摘要:
The invention relates to a vehicle suspension arm supporting structure. A receiving portion 9 is formed integrally on a subframe 5 which is formed of a light metal in such a manner as to extend transversely outwards, and a sheet steel member 15 is connected to the subframe 5 by a bolt or a nut in such a manner as to be situated below the receiving portion 9 of the subframe 5 at a predetermined interval. A base portion 13b of a suspension arm 13 is disposed between the receiving portion 9 of the subframe 5 and the sheet steel member 15, the base portion 13b of the suspension arm 13 is supported on the subframe 5 via a rubber bushing joint 14 by a connecting bolt 16 which vertically passes through the receiving portion 9 of the subframe 5 and the sheet steel member 15, and the receiving portion 9 of the subframe 5 is connected to a side member 4 by the connecting bolt 16.
摘要:
A radiation imaging system is configured by a collimator 30A including a detector 21 with a discrete detection pixel corresponding with a pixel and a plurality of radiation passages 31 and looks into a plurality of detectors 21 through one radiation passage 31 to set a step width of rotation around a rotation center axis X1 only for an angle θp made by lines provided by connecting a center detector 21 of the radiation passage 31 and the adjacent two detectors 21. In the case of generating a flat plane projection image for one direction, radio-graphing is carried out on a projection image in a plurality of predetermined angle positions (−θp, 0, +θp) in the circumferential direction of the rotation center axis X1 and thereby one plane projection image is obtained.
摘要:
In a suctioning state, even if the amount of dust trapped in a dust collecting unit in a main air passage is increased, air suctioned from a hose connection port is branched into a first half passage and reduction in the suction air amount can be suppressed. When the suctioning state is switched to a dust moving state by switch means, the dust trapped in a pleated filter is moved to the dust collecting unit, increase in the air passage resistance at the first half passage side caused by clogging of the pleated filter can be suppressed, and reduction in suction power over time can be suppressed. Since an upper air passage and lower air passage are provided in the lid body, the dust collecting unit is exposed with the lid body opened, whereby maintenance performance of the dust collecting unit is improved.
摘要:
A microcomputer comprises: a memory which stores a predetermined program; a CPU which reads the program stored in the memory based on a predetermined instruction to perform a predetermined calculation; and a read controller which controls reading of the program from the memory, and the microcomputer further comprises: a plurality of memory areas disposed in the memory and having distinction bits; distinction unit for distinguishing the memory areas using the different distinction bits; and read access controller for prohibiting the reading from the memory area in which another program is stored based on a distinction result of the distinction unit.