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公开(公告)号：US12034487B2
公开(公告)日：2024-07-09
申请号：US17633902
申请日：2019-08-23
IPC分类号： H04B10/61 , H04B10/2575 , H04B10/2581
CPC分类号： H04B10/614 , H04B10/25753 , H04B10/2581
摘要： An object of the present invention is to provide an optical transmission system capable of easily controlling a transmission capacity and an optical signal quality even if a MIMO equalizer is provided. The optical transmission system according to the present invention is provided with an N×M MIMO equalizer, includes receivers (N units) equal in number to the spatial multiplexing order L of an optical fiber, and changes the number M of the signal beams of light transmitted through the optical fiber in the range of the spatial multiplex order L or less. The adjustment of the number M of signal beams of light makes it possible to adjust a transmission capacity and a signal quality of the optical transmission system even after construction of the transmission line.
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公开(公告)号：US12019267B2
公开(公告)日：2024-06-25
申请号：US17627866
申请日：2020-07-21
发明人： Taiji Sakamoto , Kazuhide Nakajima , Takashi Matsui , Kyozo Tsujikawa , Kunimasa Saitoh , Takeshi Fujisawa
CPC分类号： G02B6/02042 , G02B27/0012
摘要： An object of the present invention is to provide a multi-core optical fiber that can prevent an increase in bending loss even when a distance between a peripheral core and a cladding boundary is decreased, and can improve a bending loss characteristic in a state where an influence on a cutoff wavelength and a mode field diameter is small, and a design method thereof.
The multi-core optical fiber according to the present invention is an optical fiber in which two or more core regions are arranged in a cladding region having a refractive index lower than a refractive index of the core at a minimum core interval, a ring-shaped low refractive index region surrounding the core and having a refractive index lower than the refractive index of the cladding region is provided, a bending loss after the provision of the ring-shaped low refractive index region is reduced as compared with a characteristic in a case where the ring-shaped low refractive index region is not provided, and at the same time, a change in mode field diameter after the provision of the ring-shaped low refractive index region is not changed as compared with a characteristic in a case where the ring-shaped low refractive index region is not provided.-
公开(公告)号：US20210263213A1
公开(公告)日：2021-08-26
申请号：US17260401
申请日：2019-07-11
发明人： Taiji Sakamoto , Yoshiteru Abe , Kazuhide Nakajima
摘要： A planar waveguide having M×N number of cores and to which M number of fibers having N number of cores are connected. In the planar waveguide, in a connecting end surface of the planar waveguide to which the fibers are connected, P number of fibers having Q number of cores are connected, M×N is equal to P×Q, the planar waveguide includes a plurality of the cores arranged in a horizontal direction at the same height position in the planar waveguide, and a laminated structure having the cores at different positions in a height direction, so as to be aligned with the cores of the fibers connected to the connecting end surface, and the positions of the M×N number of cores are constant in the height direction, and change only in the horizontal direction.
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公开(公告)号：US10545333B2
公开(公告)日：2020-01-28
申请号：US15772263
申请日：2016-11-17
摘要： A photonic crystal fiber according to the present invention has a plurality of holes arranged in the optical fiber along a longitudinal direction, in which the holes are arranged such that, in a cross section, a hole ratio which is an area of the holes per unit area is larger in a central side than in an outer side in a portion corresponding to a cladding and that a wide core area can be obtained while the number of modes that can be propagated is limited to several. Moreover, in a high-power optical transmission system according to the present invention, the amount of axis misalignment between the central axis of a laser oscillator and the central axis of the photonic crystal fiber is less than or equal to a certain amount.
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公开(公告)号：US09252872B2
公开(公告)日：2016-02-02
申请号：US13923990
申请日：2013-06-21
IPC分类号： H04B10/08 , H04B10/079 , G02B6/02 , H04B10/071
CPC分类号： H04B10/0795 , G02B6/02042 , H04B10/071
摘要： For example, of a first intensity distribution waveform WF1 indicated by a distance distribution of an intensity of light which returns to one end of a core of a multicore fiber, and a second intensity distribution waveform WF2 indicated by a distance distribution of an intensity of light which returns to the other end of the core, the second intensity distribution waveform WF2 is inverted. Further, for example, an inverted intensity distribution waveform WF3 which is inverted and the first intensity distribution waveform WF1 which is not inverted are added.
摘要翻译： 例如，由返回到多芯光纤的芯的一端的光的强度的距离分布表示的第一强度分布波形WF1和由光强度的距离分布表示的第二强度分布波形WF2 其返回到核心的另一端，第二强度分布波形WF2被反转。 此外，例如，反相的反转强度分布波形WF3和未反转的第一强度分布波形WF1相加。
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公开(公告)号：US12085749B2
公开(公告)日：2024-09-10
申请号：US18009784
申请日：2020-06-24
CPC分类号： G02B6/02042 , G02B6/02342
摘要： The purpose of the present invention is to provide an optical fiber evaluation equipment and an optical fiber evaluation method that evaluate the center of a cladding of an MCF and a deviation of the center of each core of the MCF from a design value with ease and high accuracy.
The optical fiber evaluation equipment according to the present invention approximates the outside diameter of a cladding by a circle, based on a cross-sectional image of an MCF, and determines the center of the circle as the center of the cladding. In addition, the optical fiber evaluation equipment according to the present invention obtains the center coordinates of cores with an origin at the center of the circle, rotates the cross-sectional image so as to minimize a difference between the center coordinates and design coordinates of each core, and derives the minimum value thereof as the amount of deviation of the center of each core.-
公开(公告)号：US11956070B2
公开(公告)日：2024-04-09
申请号：US17760541
申请日：2019-09-17
IPC分类号： H04J14/04 , H04B7/0413 , H04B10/079 , H04B10/2581
CPC分类号： H04J14/04 , H04B7/0413 , H04B10/07953 , H04B10/2581
摘要： An object of the present invention is to provide an optical transmission system capable of controlling a transmission capacity and a signal processing load of a MIMO equalizer, without depending on the number of propagation modes of the optical fiber. The present optical transmission system includes an optical fiber 11 with the number of spatial modes being L (an integer of 2 or greater), an optical multiplexer 13 connected to one end of the optical fiber 11 and configured to input M (a natural number of L or less) signal beams of light to the optical fiber 11 and cause the M input signal beams of light to be propagated for each of the spatial modes of the optical fiber 11, an optical demultiplexer 14 connected to another end of the optical fiber 11 and configured to demultiplex a propagated beam of light propagated through the optical fiber 11 for each of the spatial modes of the optical fiber 11, N (N=L) receivers 15 configured to each receive a demultiplexed beam of light obtained by demultiplexing the propagated beam of light, a signal generation apparatus 17 configured to generate P (an integer of from M to L) combined signals from the N received signals, and a P×M MIMO equalizer 16 configured to receive the P combined signals to output M demodulated signals.
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公开(公告)号：US11906783B2
公开(公告)日：2024-02-20
申请号：US17764239
申请日：2019-10-08
发明人： Yoko Yamashita , Masaki Wada , Takashi Matsui , Kazuhide Nakajima
CPC分类号： G02B6/29313 , G02B6/3861
摘要： An object of the present invention is to provide a core position recognition method, a connection method, and a connection apparatus that can simplify connection operations, and reduce rotational displacement and positional displacement. The connection apparatus according to the present invention includes a function capable of acquiring the rotation amount of an MCF during the bonding/fixing step. Specifically, the connection apparatus of the present invention uses an MCF with lines drawn on a side surface thereof, thereby recognizing the rotation amount of the MCF from the side surface, and calculating the absolute positions of the cores. The connection apparatus according to the present invention can recognize the absolute position s of the cores from a side image of an MCF in a state in which the MCF has been rotated. By forming a waveguide on a glass substrate serving as a connection destination so as to match the absolute positions of the cores, the rotational and positional displacements of the MCF can be eliminated, thus making it possible to reduce the connection loss.
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公开(公告)号：US20240027678A1
公开(公告)日：2024-01-25
申请号：US18232524
申请日：2023-08-10
发明人： Takashi Matsui , Kazuhide Nakajima
CPC分类号： G02B6/02042 , G02B6/02004 , G02B27/0012
摘要： There are provided a multi-core optical fiber including four step-index type cores with a standard cladding diameter and having excellent mass productivity, quality, and yield while meeting desired specifications, and a design method thereof.
A multi-core optical fiber according to the present disclosure includes: four cores arranged in a square lattice shape along a longitudinal direction, each of the four cores having a step-index type refractive index distribution with a radius a; and a cladding region having a lower refractive index than that of each core and a diameter of 125±1 μm and provided on an outer peripheral portion of each core, where an absolute value of a relative refractive index difference between each core and the cladding region is Δ. The four cores are arranged so that a relationship between a minimum distance (OCT) from the center of each core to an outer periphery of the cladding region, a minimum value Λ of spacing between the cores, and the MFD at a wavelength of 1310 nm satisfies Formula C1, and the radius a of each core and the relative refractive index difference Δ between the core and the cladding region are set.
[Formula C1]
OCT≥3.73MFD+3.43
Λ≤−5.28MFD+83.54 (C1)-
30.发明授权公开(公告)号：US11815421B2
公开(公告)日：2023-11-14
申请号：US17434949
申请日：2020-02-19
发明人： Yuto Sagae , Takashi Matsui , Kyozo Tsujikawa , Kazuhide Nakajima
IPC分类号： G01M11/00
CPC分类号： G01M11/319
摘要： An objective is to provide an acoustic mode propagation speed measurement method and an acoustic mode propagation speed measurement device capable of measuring a propagation speed of an acoustic mode without cutting or processing an optical fiber wire.
According to the present invention, an acoustic mode propagation speed measurement method includes: acquiring a frequency shift spectrum of Brillouin scattered light generated in an optical fiber; fitting the frequency shift spectrum using a Gauss function; acquiring a spectral full-width at half maximum w from a fitted curve using the Gauss function; and calculating a propagation speed VA of an acoustic mode of the optical fiber by substituting the acquired spectral full-width at half maximum w into a linear function of the spectral full-width at half maximum w and the propagation speed VA of the acoustic mode.
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