Abstract: One embodiment of the present invention provides a cage for spinal interbody fusion, which has sufficient durability and allows for bone fusion with a bone implanted to the anterior disk as well as fusion between vertebrae, thereby achieving a more stable bone fusion. The cage for spinal interbody fusion according to the embodiment of the present invention comprises a cage body and a tip which is formed to extend from the cage body and have a predetermined curvature. Further, the cage body has a cavity part which is formed to penetrate from the top surface to the bottom surface of the cage body with a projection part having a plurality of projections formed on the top surface and the bottom surface, and at least one perforation part, which is perforated from the side surface adjacent to the top surface or the bottom surface to the direction of the cavity part, and is located in the anterior direction of the cavity part.

Abstract: One embodiment of the present invention provides a cage for spinal interbody fusion, which has sufficient durability and allows for bone fusion with a bone implanted to the anterior disk as well as fusion between vertebrae, thereby achieving a more stable bone fusion. The cage for spinal interbody fusion according to the embodiment of the present invention comprises a cage body and a tip which is formed to extend from the cage body and have a predetermined curvature. Further, the cage body has a cavity part which is formed to penetrate from the top surface to the bottom surface of the cage body with a projection part having a plurality of projections formed on the top surface and the bottom surface, and at least one perforation part, which is perforated from the side surface adjacent to the top surface or the bottom surface to the direction of the cavity part, and is located in the anterior direction of the cavity part.

Abstract: A measurement precision is improved and a measurement range is extended by efficiently suppressing a noise level of integrated unnecessary components from non-correlation positions. Measuring means 33 detects the Brillouin gain of a probe light output from a measurement-target optical fiber FUT while sweeping a frequency difference between the pump light and the probe light, and measures the distribution of strains of the measurement-target optical fiber FUT. An optical intensity modulator 4 performs intensity modulation on output light in synchronization with frequency modulation performed on a light source 1. Accordingly, the spectrum distribution with respect to the frequency of light from the light source 1 can be adjusted arbitrarily, and a noise spectrum shape generated at a position other than a correlation peak position and spreading over a frequency axis can be adjusted, and the peak frequency of a Lorentz spectrum generated at the correlation peak position can be measured precisely.

Abstract: A measurement precision is improved and a measurement range is extended by efficiently suppressing a noise level of integrated unnecessary components from non-correlation positions. Measuring means 33 detects the Brillouin gain of a probe light output from a measurement-target optical fiber FUT while sweeping a frequency difference between the pump light and the probe light, and measures the distribution of strains of the measurement-target optical fiber FUT. An optical intensity modulator 4 performs intensity modulation on output light in synchronization with frequency modulation performed on a light source 1. Accordingly, the spectrum distribution with respect to the frequency of light from the light source 1 can be adjusted arbitrarily, and a noise spectrum shape generated at a position other than a correlation peak position and spreading over a frequency axis can be adjusted, and the peak frequency of a Lorentz spectrum generated at the correlation peak position can be measured precisely.

Abstract: A measurement range is extended while maintaining the spatial resolution high by completely separating the increment of a probe light from noises. Modulations are performed on both probe light and pump light to differentiate both lights. Using the modulations, only the change in the probe light necessary for measuring the characteristic of a measurement-target optical fiber FUT can be separated. Accordingly, unlike the conventional technology, an optical wavelength filter becomes unnecessary. Further, in a case where an amplitude ?f of the frequency modulation of a light source 1 is made wide to some extent to make the measurement range wide while maintaining a spatial resolution ?z high, the amplitude ?f does not affect to detection of the change in the probe light. Therefore, the increment of the probe light can be completely separated from noises, thereby extending the measurement range while maintaining the spatial resolution ?z high.

Abstract: A measurement range is extended while maintaining the spatial resolution high by completely separating the increment of a probe light from noises. Modulations are performed on both probe light and pump light to differentiate both lights. Using the modulations, only the change in the probe light necessary for measuring the characteristic of a measurement-target optical fiber FUT can be separated. Accordingly, unlike the conventional technology, an optical wavelength filter becomes unnecessary. Further, in a case where an amplitude ?f of the frequency modulation of a light source 1 is made wide to some extent to make the measurement range wide while maintaining a spatial resolution ?z high, the amplitude ?f does not affect to detection of the change in the probe light. Therefore, the increment of the probe light can be completely separated from noises, thereby extending the measurement range while maintaining the spatial resolution ?z high.

Abstract: A method of fabricating a fused-type directional coupler that can be made in a simple manner. The present invention is characterized in that a pair of optical fibers satisfying a particular phase match condition are previously selected to form a fused-type directional coupler. The two optical fibers are prepared by respectively tapering and etching two identical optical fibers. The present invention can be applied to fabrication of mode-selective directional couplers utilizing symmetrical high-degree modes such as LP02 mode as well as fabrication of mode-selective directional couplers utilizing asymmetrical high-degree modes such as LP11 mode.

Abstract: A method of fabricating a fused-type directional coupler that has stable characteristics in a simple manner. According to the embodiment of the present invention, two two-mode optical fibers having identical structures, one of which having a reduced cladding diameter by chemical etching and the other of which having a reduced core and cladding diameter by heated tapering, are fused by heating and extended. The fused-type mode-selective directional coupler fabricated according to the present invention obviates the need to look for a particular pair of single mode-two mode optical fibers that satisfy the phase match condition. In addition, the mode-selective directional coupler of the present invention is more stable against change of temperature compared with conventional polished-type directional couplers that include material other than optical fibers and is easier to fabricate, because the mode-selective directional coupler of the present invention is an all-optical-fiber, fused-type directional coupler.