An Angle Spatial Division Multiplexing Device and Method for Optical Fiber Communication

Abstract

The present invention relates to the field of optical fiber communication, and particularly to an angular space division multiplexing device and method for optical fiber communication. The characteristics are as follows: at the transmitting end, the bus rotates around the optical fiber axis at an angle α for one week at the laser incident point to form a conical space, and at least two lasers aiming at the incident point are arranged in the conical space, where α is the maximum angle for the laser to enter the optical fiber to satisfy the total reflection condition; at the receiving end, optoelectronic devices are provided to receive laser information. The beneficial effects are as follows: a space division multiplexing for single-fiber communication is proposed by using the direction dimension of the laser, the optoelectronic device array is used to separate lasers in different directions, the BLAST algorithm is further used for demultiplexing, and the concentric circle grating is used for the transformation from the frequency domain to the spatial domain to realize dynamic demultiplexing, overcoming the influence of the non-linear optical characteristics of the optical fiber on dispersion, polarization state, orthogonality, light wave interference, etc., and greatly improving the space division multiplexing degree.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber communication, and particularly to an angular space division multiplexing device and method for optical fiber communication. Background Art

[0002] Currently, the multiplexing technologies for optical fiber communication include: multi-core fiber multiplexing, few-mode fiber multiplexing, few-mode multi-core fiber multiplexing, orbital angular momentum mode multiplexing, etc. The physical dimensions of multiplexing include time, frequency, polarization state, orthogonality, light wave interference, etc. An optical communication system established by using the mechanism of modulating and demodulating the spatial coherence of light belongs to SDM. The space division multiplexing technology involves technologies such as mode conversion and control, channel multiplexing / demultiplexing, optical amplification, etc. Multiplexing / demultiplexing includes multi-input multi-output (MIMO) signal processing methods, such as the BLAST algorithm. Summary of the Invention

[0003] The present invention realizes the space division multiplexing of single-fiber communication by using the direction dimension of laser, that is, by using the "spatial identification" of the directivity of laser at the transmitting end and "restoring" it at the receiving end.

[0004] The optical fibers of the present invention include: step-index (SI) fibers, near step-index fibers, graded-index (GI) fibers, others (such as triangular, W-shaped, depressed-shaped, etc.).

[0005] The transmission modes include: single-mode fibers (including polarization-maintaining fibers and non-polarization-maintaining fibers), multi-mode fibers.

[0006] The manufacturing materials include: silica fibers, multi-component glass fibers, plastic fibers, composite fibers (such as plastic cladding, liquid core, etc.), infrared materials, etc. According to the coating materials, they can also be divided into inorganic materials (such as carbon), metal materials (such as copper, nickel, etc.) and plastics.

[0007] The maximum fiber incident angle: When the laser incident on the fiber satisfies the condition of total internal reflection inside the fiber, the maximum angle allowed between the laser beam of the laser and the fiber axis.

[0008] Optical field: A collection of laser beams with multiple different angles or phases.

[0009] The technical solution of the present invention is as follows:

[0010] An angular space division multiplexing device for optical fiber communication, including a transmitting end and a receiving end, characterized in that: at the transmitting end, at least two lasers are arranged to shoot at the incident surface of the fiber at an angle less than or equal to the maximum fiber incident angle and send laser beams carrying independent information, and the laser beams contain their respective spatial angle identifications and / or spatial phase identifications; at the receiving end, an optoelectronic device is provided to receive the laser beams and realize demultiplexing according to the spatial angle identifications and / or spatial phase identifications contained in the laser beams.

[0011] The described angular space division multiplexing device for optical fiber communication is characterized in that: at the transmitting end, the busbar rotates around the optical fiber axis for one week at the maximum optical fiber incident angle at the laser incident point to form a conical space, and at least two lasers aiming at the incident point are arranged in the conical space.

[0012] The described angular space division multiplexing device for optical fiber communication is characterized in that: the optoelectronic device at the receiving end is an optoelectronic device array.

[0013] The described angular space division multiplexing device for optical fiber communication is characterized in that: at least two optoelectronic device arrays with a certain optical path difference are arranged at the receiving end, and the optoelectronic device arrays are connected to a demultiplexer.

[0014] The described angular space division multiplexing device for optical fiber communication is characterized in that: a partially transmissive and reflective mirror is arranged at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays receive optical fields with different optical paths.

[0015] The described angular space division multiplexing device for optical fiber communication is characterized in that: an optical fiber splitter is arranged at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays receive optical fields with different optical paths.

[0016] The described angular space division multiplexing device for optical fiber communication is characterized in that: a grating is arranged at the receiving end, and preprocessing before demultiplexing is performed by the grating.

[0017] The described angular space division multiplexing device for optical fiber communication is characterized in that: the grating is a concentric circle grating.

[0018] The described angular space division multiplexing device for optical fiber communication is characterized in that: a reference light source is arranged at the receiving end, and demultiplexing processing is realized by the interference of the reference light and the optical field.

[0019] The described angular space division multiplexing device for optical fiber communication is characterized in that: a reference light source is arranged at the transmitting end, and the reference light beam and the laser beam carrying information are incident on the optical fiber together.

[0020] The described angular space division multiplexing device for optical fiber communication is characterized in that: the incident surface of the optical fiber is a plane, or a convex spherical surface, or a concave spherical surface.

[0021] The described angular space division multiplexing device for optical fiber communication is characterized in that: a conical optical fiber interface is arranged at the transmitting end, and different laser beams are guided by the conical optical fiber interface to be incident on the optical fiber.

[0022] An angular space division multiplexing method for optical fiber communication, characterized in that the method includes: at the transmitting end, arranging at least two lasers that emit laser beams carrying independent information towards the incident surface of the optical fiber at an angle less than or equal to the maximum incident angle of the optical fiber, and the laser beams include their respective spatial angle identifiers and / or spatial phase identifiers; at the receiving end, arranging an optoelectronic device device to receive the laser beams and perform demultiplexing according to the spatial angle identifier or spatial phase identifier included in the laser beams.

[0023] The angular space division multiplexing method for optical fiber communication described above is further characterized in that: at the transmitting end, the bus rotates around the optical fiber axis at the maximum incident angle of the optical fiber for one week at the laser incident point to form a conical space, and at least two lasers aiming at the incident point are arranged in the conical space.

[0024] The angular space division multiplexing method for optical fiber communication described above is further characterized in that: the optoelectronic device array at the receiving end receives the laser light field and separates different independent information.

[0025] The angular space division multiplexing method for optical fiber communication described above is further characterized in that: at the receiving end, at least two optoelectronic device arrays with an optical path difference of △L1 are arranged. The optoelectronic device arrays respectively receive the laser light fields with an optical path difference of △L1, and the two-dimensional electrical signals of the optoelectronic device arrays are sent to the demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1), I2 = F2(△L1), where I1 is information flow 1, I2 is information flow 2, F1 is the demultiplexing function of I1, and F2 is the demultiplexing function of I2.

[0026] The angular space division multiplexing method for optical fiber communication described above is further characterized in that: at the receiving end, n + 1 partial transparent and reflective mirrors are arranged. The partial transparent and reflective mirrors split the laser beam to form optical path differences of △L1, △L2, …… △Ln. The optoelectronic device arrays corresponding to different optical path differences respectively receive the light fields with different optical paths, and the two-dimensional electrical signals of the optoelectronic device arrays are sent to the demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1, △L2, …… △Ln), I2 = F2(△L1, △L2, …… △Ln), In = Fn(△L1, △L2, …… △Ln), where I1 is information flow 1, I2 is information flow 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information flow n, and Fn is the demultiplexing function of In.

[0027] The described angular space-division multiplexing method for optical fiber communication is further characterized in that: at the receiving end, n + 1 optical fiber splitters are provided. After the laser is split by the optical fiber splitters, optical path differences of △L1, △L2, …… △Ln are formed. Photoelectric device arrays corresponding to different optical path differences respectively receive optical fields with different optical paths. The two-dimensional electrical signals of the photoelectric device arrays are sent to a demultiplexer for demultiplexing operations. Algorithms are I1 = F1(△L1, △L2, …… △Ln), I2 = F2(△L1, △L2, …… △Ln), In = Fn(△L1, △L2, …… △Ln), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

[0028] The described angular space-division multiplexing method for optical fiber communication is further characterized in that: a grating is provided in the optical path at the receiving end, and the grating performs pre-demultiplexing processing on the optical field.

[0029] The described angular space-division multiplexing method for optical fiber communication is further characterized in that: a concentric circular grating performs pre-demultiplexing processing on the optical field.

[0030] The described angular space-division multiplexing method for optical fiber communication is further characterized in that: at the receiving end, demultiplexing processing is realized by the interference of a reference light and an optical field.

[0031] The described angular space-division multiplexing method for optical fiber communication is further characterized in that: a reference light source is provided at the sending end. The reference light and the laser beam carrying information are incident on the optical fiber together. After exiting at the receiving end, demultiplexing processing is realized by the interference of the reference light and the optical field.

[0032] Since the present invention can achieve dynamic demultiplexing and overcome the influence of the non-linear optical characteristics of the optical fiber on dispersion, polarization state, orthogonality, light wave interference, etc., that is, the receiving end of the present invention can not consider the beam space angle and space phase conditions of the sending end, nor consider the physical dimensions of multiplexing such as time, frequency, polarization state, orthogonality, light wave interference, etc., as long as demultiplexing is performed at the receiving end. Therefore, the receiving end of the present invention can be generalized as:

[0033] A space-division multiplexing receiving device for optical fiber communication, characterized in that: a photoelectric device array is provided at the receiving end for receiving a laser beam and realizing demultiplexing according to the space angle identifier and / or space phase identifier included in the laser beam.

[0034] The described space-division multiplexing receiving device for optical fiber communication is characterized in that: at least two photoelectric device arrays with a certain optical path difference are provided at the receiving end, and the photoelectric device arrays are connected to a demultiplexer.

[0035] The described space-division multiplexing receiving device for optical fiber communication is characterized in that: a partially transmissive and reflective mirror is provided at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays can receive light fields with different optical paths.

[0036] The described space-division multiplexing receiving device for optical fiber communication is characterized in that: an optical fiber splitter is provided at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays can receive light fields with different optical paths.

[0037] The described space-division multiplexing receiving device for optical fiber communication is characterized in that: a grating is provided at the receiving end, and pre-processing before demultiplexing is performed by the grating.

[0038] The described space-division multiplexing receiving device for optical fiber communication is characterized in that: the grating is a concentric circle grating.

[0039] The described space-division multiplexing receiving device for optical fiber communication is characterized in that: a reference light source is provided at the receiving end, and demultiplexing processing is achieved by the interference of the reference light and the light field.

[0040] The described space-division multiplexing receiving device for optical fiber communication is characterized in that: a reference light source is provided at the transmitting end, and the reference light beam and the laser beam carrying information are incident on the optical fiber together.

[0041] A receiving method for space-division multiplexing in optical fiber communication, characterized in that the method includes: an optoelectronic device array is provided at the receiving end to receive the laser beam and perform demultiplexing according to the spatial angle identifier and / or spatial phase identifier included in the laser beam.

[0042] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: the optoelectronic device array at the receiving end receives the laser light field and separates different independent information.

[0043] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: at least two optoelectronic device arrays with a light path difference of △L1 are provided at the receiving end. The optoelectronic device arrays respectively receive laser light fields with a light path difference of △L1, and the two-dimensional electrical signals of the optoelectronic device arrays are sent to the demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1), I2 = F2(△L1), where I1 is information flow 1, I2 is information flow 2, F1 is the demultiplexing function of I1, and F2 is the demultiplexing function of I2.

[0044] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: at the receiving end, n + 1 partially transmissive and reflective mirrors are provided. The partially transmissive and reflective mirrors split the laser beam to form optical path differences of △L1, △L2, …… △Ln. Photoelectric device arrays corresponding to different optical path differences respectively receive optical fields with different optical paths. The two-dimensional electrical signals of the photoelectric device arrays are sent to a demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1, △L2, …… △Ln), I2 = F2(△L1, △L2, …… △Ln), In = Fn(△L1, △L2, …… △Ln), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

[0045] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: at the receiving end, n + 1 optical fiber splitters are provided. The optical fiber splitters split the laser beam to form optical path differences of △L1, △L2, …… △Ln. Photoelectric device arrays corresponding to different optical path differences respectively receive optical fields with different optical paths. The two-dimensional electrical signals of the photoelectric device arrays are sent to a demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1, △L2, …… △Ln), I2 = F2(△L1, △L2, …… △Ln), In = Fn(△L1, △L2, …… △Ln), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

[0046] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: a grating is provided in the optical path at the receiving end, and the grating performs pre-processing for demultiplexing on the optical field.

[0047] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: a concentric circle grating performs pre-processing for demultiplexing on the optical field.

[0048] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: at the receiving end, demultiplexing processing is achieved by the interference of a reference light and an optical field.

[0049] The described receiving method for space-division multiplexing in optical fiber communication is further characterized in that: a reference light source is provided at the sending end. The reference light and the laser beam carrying information are incident on the optical fiber together, and after exiting at the receiving end, demultiplexing processing is achieved by the interference of the reference light and the optical field.

[0050] The beneficial effects of the present invention are as follows: A space-division multiplexing for single-fiber communication is proposed by utilizing the direction dimension of laser. An optoelectronic device array is used to separate lasers in different directions, and further the BLAST algorithm is used for demultiplexing. A concentric circle grating is used for the transformation from the frequency domain to the spatial domain to achieve dynamic demultiplexing, overcoming the influence of the nonlinear optical characteristics of the optical fiber on dispersion, polarization state, orthogonality, light wave interference, etc., and greatly improving the space-division multiplexing degree. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the principle of the present invention.

[0052] Figure 2 It is an embodiment in which the fiber incident surface of the device of the present invention is a convex spherical surface.

[0053] Figure 3 It is an embodiment in which the fiber incident surface of the device of the present invention is a concave spherical surface.

[0054] Figure 4 It is an embodiment in which an optoelectronic device array is arranged at the receiving end of the device of the present invention.

[0055] Figure 5 It is an embodiment in which at least two optoelectronic device arrays are arranged at the receiving end of the device of the present invention and demultiplexing operations are performed.

[0056] Figure 6 It is a schematic diagram of the optoelectronic device array.

[0057] Figure 7 It is an implementation scheme of the present invention in which a partially transparent reflector is used to split the light field.

[0058] Figure 8 It is an implementation scheme of the present invention in which multiple partially transparent reflectors are used to split the light field.

[0059] Figure 9 It is an implementation scheme of the present invention in which an optical fiber splitter is used to split the light field.

[0060] Figure 10 It is an implementation scheme of the present invention in which a grating device is introduced into the optical path as pre-processing for demultiplexing.

[0061] Figure 11 It is an implementation scheme of the present invention in which a reference light is introduced for interference processing and then demultiplexing is performed.

[0062] Figure 12 It is an implementation scheme of the present invention in which a tapered optical fiber is used as the entrance of the transmitting end.

[0063] Figure 13 It is a schematic diagram of the principle of demultiplexing after introducing a reference light for interference processing.

[0064] Figure 14 An implementation scheme for introducing a reference light at the transmitting end. Specific implementation manners

[0065] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0066] Referring to Figure 1 is a schematic diagram of the principle of the present invention. The device includes a transmitting end and a receiving end. At the transmitting end, the bus bar 1101 rotates around the optical fiber axis 1102 at an angle α1 for one week at the laser incident point O to form a conical space. At least two lasers 102 and 103 aiming at the incident point O are arranged in the conical space (including the conical surface). α1 is the maximum angle for the laser to enter the optical fiber to satisfy the total reflection condition, and α1 is defined as the maximum optical fiber incident angle. 101 is the optical fiber incident section. The total reflection incident angle of the optical fiber is θ (critical angle). The incident angle is the angle θ between the incident light and the normal of the incident surface. The calculation method of the critical angle is θ = arcsin(m / n), where m is the refractive index of the cladding and n is the refractive index of the core. At the receiving end, optoelectronic devices 202 and 203 are provided to receive laser information. 201 is the outgoing section of the optical fiber. The light field composed of laser beams with different spatial angles exits at the interface of the outgoing section 201 of the optical fiber. The lasers in the conical space can be lasers with different incident angles, or lasers with the same incident angle but not in the same spatial position. The more the number of arranged lasers, the higher the multiplexing degree of the device. Continuing to refer to Figure 2 、 Figure 3 , Figure 2 is an implementation manner in which the incident surface of the optical fiber of the device of the present invention is a convex spherical surface. 104 is the convex spherical incident surface, and 204 is the convex spherical outgoing surface. Figure 3 is an implementation manner in which the incident surface of the optical fiber of the device of the present invention is a concave spherical surface. 1041 is the concave spherical incident surface, and 2041 is the concave spherical outgoing surface. In these two cases, the optical surface of the laser incident surface changes. Under the condition of the same total reflection angle θ of the optical fiber, α1 > α2 and α1 > α3. The legend of the present invention uses a step (SI) type optical fiber diagram, and the principle of the graded index (GI) type optical fiber is the same.

[0067] Continuing to refer to Figure 1 , the features of the present invention are: at the transmitting end, the bus bar rotates around the optical fiber axis at an angle α1 for one week at the laser incident point to form a conical space. At least two lasers aiming at the incident point are arranged in the conical space and send laser beams carrying independent information. The laser beams contain their respective spatial angle identifiers. α1 is the maximum angle for the laser to enter the optical fiber to satisfy the total reflection condition (i.e., the maximum optical fiber incident angle); at the receiving end, optoelectronic devices are provided to receive the laser beams and perform demultiplexing according to the spatial angle identifiers contained in the laser beams.

[0068] Continuing to refer to Figure 1, α1 is defined as the maximum incident angle of the optical fiber. If the incident point of the laser moves on the optical fiber incident surface 1103 (i.e., it does not enter at the center of the optical fiber axis), as long as the angle between the incident light ray and the optical fiber axis is less than or equal to α1, the feature of the present invention is generalized as follows: at the transmitting end, lasers are arranged to shoot at the optical fiber incident surface, with at least two lasers shooting at the optical fiber incident surface at an angle less than or equal to the maximum incident angle of the optical fiber and sending laser beams carrying independent information, and the laser beams contain their respective spatial angle identifiers; at the receiving end, optoelectronic devices are arranged to receive the laser beams and perform demultiplexing according to the spatial angle identifiers contained in the laser beams.

[0069] Figure 4 This is an embodiment of arranging an optoelectronic device array at the receiving end of the device of the present invention. 201 is the outgoing section of the optical fiber, 401 is the optoelectronic device array, and the optical field outgoing from the optical fiber irradiates on the surface of the optoelectronic device array 401 to form the X and Y plane distribution information of the optoelectronic device array. In this way, the angle information or interference information of the laser is separated in the plane space, and the optoelectronic device array receives the laser optical field and separates different independent information (i.e., demultiplexes laser beams with different spatial angles).

[0070] The feature of the present invention is: at the transmitting end, at least two lasers are arranged to shoot at the incident surface of the optical fiber at an angle less than or equal to the maximum incident angle of the optical fiber and send laser beams carrying independent information, and the laser beams contain their respective spatial angle identifiers; at the receiving end, an optoelectronic device device is arranged to receive the laser beams and perform demultiplexing according to the spatial angle identifiers contained in the laser beams. Or: at the transmitting end, at least two lasers are arranged to shoot at the incident surface of the optical fiber at an angle less than or equal to the maximum incident angle of the optical fiber and send laser beams carrying independent information, and the laser beams contain their respective spatial phase identifiers; at the receiving end, an optoelectronic device device is arranged to receive the laser beams and perform demultiplexing according to the spatial phase identifiers contained in the laser beams.

[0071] At Figure 4 On this basis, further referring to Figure 10 , a grating can be arranged in the optical path of the outgoing optical field for spatial phase separation.

[0072] At Figure 4 On this basis, further referring to Figure 11 , a reference light can be used in the optical path of the outgoing optical field for interference to achieve spatial phase separation.

[0073] Figure 5 This is an embodiment of arranging at least two optoelectronic device arrays at the receiving end of the device of the present invention and performing demultiplexing operations. 401 is the optoelectronic device array, and a parallel optoelectronic device array 501 is arranged at a position with a distance △L1 from the back of the light-receiving surface of the optoelectronic device array 401. Here, the optoelectronic device array 401 can use Figure 6Schematic diagrams of optoelectronic device arrays: (b) spaced arrangement and (c) wide-spacing sparse arrangement. In this way, part of the light can pass through the gaps between optoelectronic device units and exit from the back of the light-receiving surface of the optoelectronic device array 401, enabling the optoelectronic device array 501 to receive light. The two-dimensional electrical signals of the optoelectronic device array 401 (the X and Y plane distribution information of the optoelectronic device array, separating the angle information or interference information of the laser in the plane space) and the two-dimensional electrical signals of the optoelectronic device array 501 (the X and Y plane distribution information of the optoelectronic device array, separating the angle information or interference information of the laser in the plane space) are transmitted to the demultiplexer for demultiplexing operations to separate the information streams, such as information stream 1 and information stream 2. Demultiplexing algorithms: I1 = F1(△L1), I2 = F2(△L1), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, and F2 is the demultiplexing function of I2.

[0074] Based on Figure 5 and further referring to Figure 10 , a grating can be set in the optical path of the output light field (including the optical paths of 401 and / or 501) for spatial phase separation.

[0075] Based on Figure 5 and further referring to Figure 11 , a reference light can be used for interference in the optical path of the output light field (including the optical paths of 401 and / or 501) to achieve spatial phase separation.

[0076] Figure 6 Figure [ID number] is a schematic diagram of an optoelectronic device array. The optoelectronic device array is composed of arranged optoelectronic device units. According to the spacing between optoelectronic device units, it can be divided into the following types: (a) close arrangement: the spacing between optoelectronic device units is 0; (b) spaced arrangement: the spacing between optoelectronic device units is the distance of one optoelectronic unit; (c) wide-spacing sparse arrangement: the spacing between optoelectronic device units is the distance of multiple optoelectronic units. If the geometric size of the optoelectronic device units in the optoelectronic device array is much larger than the light wave wavelength, no light wave interference phenomenon will occur. If optoelectronic device units with a size adapted to the manufacturing and working laser wavelength are fabricated, a light wave interference phenomenon will occur (the effect of introducing a grating). Specifically, for example, an optoelectronic device array with 10-nanometer to 1000-nanometer rectangular optoelectronic device units arranged in a spaced manner will exhibit a light wave interference phenomenon. The optoelectronic device array can be a CCD device or a CMOS device.

[0077] Figure 7This is an implementation scheme of the present invention that uses a partially transparent reflector to split the optical field. Considering that the present invention requires multiple splits of the optical field, a scheme of using a partially transparent reflector to split the optical field is adopted. The partially transparent reflector is, for example, a semi-transparent flat mirror. Since a semi-transparent flat mirror will lose 50% of the light intensity in one split, it is not conducive to multiple splits. Specifically, a 10% transparent flat mirror can be considered during implementation, so that multiple splits can be achieved under the condition of meeting the light intensity requirements. Figure 7 In this figure, 701 is a partially transparent reflector, 702 is an optoelectronic device array, and 703 is another optoelectronic device array. The laser optical field is emitted from the output section 201 of the optical fiber to the partially transparent reflector 701. Part of the optical field is reflected by the partially transparent reflector 701 to the optoelectronic device array 702, and part of the optical field is transmitted through the partially transparent reflector 701 to the optoelectronic device array 703. The two-dimensional electrical signals of the optoelectronic device array 702 (the X and Y plane distribution information of the optoelectronic device array, separating the angle information or interference information of the laser in the plane space) and the two-dimensional electrical signals of the optoelectronic device array 703 (the X and Y plane distribution information of the optoelectronic device array, separating the angle information or interference information of the laser in the plane space) are transmitted to the demultiplexer for demultiplexing operations to separate the information streams, such as information stream 1 and information stream 2. Assume that the optical path difference between the optical field reaching the optoelectronic device array 702 and the optoelectronic device array 703 is △L1. The demultiplexing algorithm: I1 = F1(△L1), I2 = F2(△L1), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, and F2 is the demultiplexing function of I2.

[0078] Figure 8 This is an implementation scheme of the present invention that uses multiple partially transparent reflectors to split the optical field. Based on the implementation scheme shown in Figure 7 On this basis, the optical field splitting is further increased. Specifically, a partially transparent reflector 801 is added for secondary splitting, and a partially transparent reflector 803 is added for tertiary splitting, and optical path differences △L1 and △L2 are respectively formed. The optoelectronic device array 702 receives the optical field with an optical path difference of 0, the optoelectronic device array 802 receives the optical field with an optical path difference of △L1, and the optoelectronic device array 804 receives the optical field with an optical path difference of △L2. The two-dimensional electrical signals of all optoelectronic device arrays are transmitted to the demultiplexer for demultiplexing operations to separate the information streams. The demultiplexing algorithm is I1 = F1(△L1, △L2,... △Ln), I2 = F2(△L1, △L2,... △Ln), In = Fn(△L1, △L2,... △Ln), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

[0079] Figure 9This is an implementation scheme of the present invention for splitting the optical field using an optical fiber splitter. 901, 902, and 905 are optical fiber splitters, 903 and 906 are the output segments of the splitting optical fibers, and 904 and 907 are the corresponding optoelectronic device arrays respectively. The optical fiber splitter 901 performs the first splitting of the optical field, and the original optical field is guided by the optical fiber output segment 201 to irradiate the optoelectronic device array 401. The first splitting of the optical field is followed by the second splitting of the optical field by the optical fiber splitter 902. Part of the optical field is guided by the optical fiber output segment 903 to irradiate the optoelectronic device array 904, and at the same time, an optical path difference of △L1 is introduced. The optical fiber splitter 905 performs the third splitting of the optical field, and part of the optical field is guided by the optical fiber output segment 906 to irradiate the optoelectronic device array 907, and at the same time, an optical path difference of △L2 is introduced. The two-dimensional electrical signals of all optoelectronic device arrays are transmitted to the demultiplexer for demultiplexing operations to separate the information streams. The demultiplexing algorithms are I1 = F1(△L1, △L2, …… △Ln), I2 = F2(△L1, △L2, …… △Ln), In = Fn(△L1, △L2, …… △Ln), where I1 is the information stream 1, I2 is the information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is the information stream n, and Fn is the demultiplexing function of In.

[0080] Figure 10 This is an implementation scheme of the present invention for introducing a grating device as pre-processing before demultiplexing in the optical path. 1001 is a grating, which is arranged in the optical path where the optical field irradiates the optoelectronic device array 401. At the sending end, there is an interference phenomenon among the lasers emitting lasers at different spatial angles during transmission. At the receiving end, the grating is used to perform interference cancellation to obtain planar two-dimensional light spots to achieve spatial separation of demultiplexing. The method can also be applied to all or part of the optical paths of all implementation schemes of the present invention. In particular, Figure 6 For the schematic diagrams of the optoelectronic device arrays (b) arranged at intervals and (c) arranged widely and sparsely, in this way, the optoelectronic device array automatically introduces the grating function. Since all the lasers at the sending end aim at one incident point, it is a better choice to use a concentric circle grating at the receiving end.

[0081] Figure 11 This is an implementation scheme of the present invention for demultiplexing after introducing a reference light for interference processing. At the receiving end, a reference light is used for interference to obtain planar two-dimensional light spots to achieve spatial separation of demultiplexing. Continue to refer to Figure 13It is a schematic diagram of the principle of demultiplexing after interference processing by introducing a reference light. After the reference light and the signal light meet, a spatial interference region 1301 is formed. An optoelectronic device array 401 is arranged in the spatial interference region. Since different signal lights (lasers) have different spatial phases, they are distributed at different spatial positions after interfering with the reference light. The plane of the optoelectronic device array 401 realizes spatial separation, and the two-dimensional electrical signals of the optoelectronic device array 401 are separated and output. Assuming that a certain signal light is a 0, 1 signal, interference spots of 0 and 1 will appear at the determined coordinate positions on the plane of the optoelectronic device array 401. The said method can also be applied to all or part of the optical paths of all embodiments of the present invention. Considering that the reference light can be introduced at the receiving end or at the sending end, refer to Figure 14 For the embodiment of introducing the reference light at the sending end, preferably, the reference light is injected along the optical fiber axis 1102 at the sending end. In this way, there is a fixed phase relationship with respect to the laser beams of other spatial phases. Since the transmission environment characteristics are the same, the original spatial phase relationship can be maintained after the light field exits at the receiving end, which is beneficial to the demultiplexing separation of the spatial phase. Further, a concentric circular grating can be introduced at the receiving end as pre-processing before demultiplexing.

[0082] Figure 12 It is an embodiment of the present invention using a tapered optical fiber as the sending end entrance. 1201 is a tapered optical fiber interface, connecting the incident sections of each branch optical fiber. Lasers 1202, 1203, and 1204 are respectively incident on their corresponding optical fiber incident sections, and the laser beams are mixed and then transmitted in the optical fiber through the 101 optical fiber incident section.

[0083] As a special case of the present invention, the light rays of at least two lasers at the sending end are on the same straight line (that is, the light beams of the two lasers coincide, realized by using a partially transparent and reflective mirror), but the phases or polarization directions of the lasers are kept different, and spatial separation is performed at the receiving end through grating interference or reference light interference. That is, the claim of this case: "At the sending end, the generatrix rotates around the optical fiber axis by an angle α for one week at the laser incident point to form a conical space, and at least two lasers aiming at the incident point are arranged in the conical space, where α is the maximum angle for the laser to enter the optical fiber to satisfy the total reflection condition; at the receiving end, optoelectronic devices are arranged to receive laser information." also includes this situation.

[0084] The present invention can continue to integrate multiplexing of other physical dimensions, such as time, frequency, polarization state, orthogonality, light wave interference, etc.

[0085] The demultiplexing algorithm of the present invention includes multi-input multi-output (MIMO) signal processing methods, such as the BLAST algorithm.

[0086] Since the present invention can achieve dynamic demultiplexing and overcome the influence of the non-linear optical characteristics of optical fibers on dispersion, polarization state, orthogonality, light wave interference, etc., that is, the receiving end of the present invention can ignore the beam spatial angle and spatial phase conditions of the transmitting end, and also ignore the physical dimensions of multiplexing such as time, frequency, polarization state, orthogonality, light wave interference, etc., as long as demultiplexing is performed at the receiving end, the receiving end of the present invention can be generalized as:

[0087] An optical space division multiplexing receiving device for optical fiber communication, characterized in that: an optoelectronic device array is provided at the receiving end for receiving a laser beam and achieving demultiplexing according to the spatial angle identifier and / or spatial phase identifier included in the laser beam.

[0088] The optical space division multiplexing receiving device for optical fiber communication described above is characterized in that: at least two optoelectronic device arrays with a certain optical path difference are provided at the receiving end, and the optoelectronic device arrays are connected to a demultiplexer.

[0089] The optical space division multiplexing receiving device for optical fiber communication described above is characterized in that: a partially transmissive and reflective mirror is provided at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays receive light fields with different optical paths.

[0090] The optical space division multiplexing receiving device for optical fiber communication described above is characterized in that: an optical fiber splitter is provided at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays receive light fields with different optical paths.

[0091] The optical space division multiplexing receiving device for optical fiber communication described above is characterized in that: a grating is provided at the receiving end, and pre-processing before demultiplexing is performed by the grating.

[0092] The optical space division multiplexing receiving device for optical fiber communication described above is characterized in that: the grating is a concentric circle grating.

[0093] The optical space division multiplexing receiving device for optical fiber communication described above is characterized in that: a reference light source is provided at the receiving end, and demultiplexing processing is achieved by the interference of the reference light and the light field.

[0094] An optical space division multiplexing receiving method for optical fiber communication, characterized in that the method includes: an optoelectronic device array is provided at the receiving end for receiving a laser beam and achieving demultiplexing according to the spatial angle identifier and / or spatial phase identifier included in the laser beam.

[0095] The optical space division multiplexing receiving method for optical fiber communication described above is further characterized in that: the optoelectronic device array at the receiving end receives the laser light field and separates different independent information.

[0096] The described receiving method for spatial division multiplexing in optical fiber communication is further characterized in that: at the receiving end, at least two optoelectronic device arrays with an optical path difference of ΔL1 are set. The optoelectronic device arrays respectively receive laser light fields with an optical path difference of ΔL1. The two-dimensional electrical signals of the optoelectronic device arrays are sent to a demultiplexer for demultiplexing operations. The algorithms are I1 = F1(ΔL1), I2 = F2(ΔL1), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, and F2 is the demultiplexing function of I2.

[0097] The described receiving method for spatial division multiplexing in optical fiber communication is further characterized in that: at the receiving end, n + 1 partially transparent and reflective mirrors are set. The partially transparent and reflective mirrors split the laser beam to form optical path differences of ΔL1, ΔL2,..., ΔLn. The optoelectronic device arrays corresponding to different optical path differences respectively receive light fields with different optical paths. The two-dimensional electrical signals of the optoelectronic device arrays are sent to a demultiplexer for demultiplexing operations. The algorithms are I1 = F1(ΔL1, ΔL2,..., ΔLn), I2 = F2(ΔL1, ΔL2,..., ΔLn), In = Fn(ΔL1, ΔL2,..., ΔLn), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

[0098] The described receiving method for spatial division multiplexing in optical fiber communication is further characterized in that: at the receiving end, n + 1 optical fiber splitters are set. The optical fiber splitters split the laser beam to form optical path differences of ΔL1, ΔL2,..., ΔLn. The optoelectronic device arrays corresponding to different optical path differences respectively receive light fields with different optical paths. The two-dimensional electrical signals of the optoelectronic device arrays are sent to a demultiplexer for demultiplexing operations. The algorithms are I1 = F1(ΔL1, ΔL2,..., ΔLn), I2 = F2(ΔL1, ΔL2,..., ΔLn), In = Fn(ΔL1, ΔL2,..., ΔLn), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

[0099] The described receiving method for spatial division multiplexing in optical fiber communication is further characterized in that: a grating is set in the optical path at the receiving end, and the grating performs pre-processing for demultiplexing on the light field.

[0100] The described receiving method for spatial division multiplexing in optical fiber communication is further characterized in that: a concentric circle grating performs pre-processing for demultiplexing on the light field.

[0101] The described receiving method for spatial division multiplexing in optical fiber communication is further characterized in that: at the receiving end, demultiplexing processing is realized by the interference of a reference light and a light field.

[0102] The described receiving method for spatial division multiplexing in optical fiber communication is further characterized in that: a reference light source is provided at the transmitting end, the reference light and the laser beam carrying information are incident on the optical fiber together, and after exiting at the receiving end, the reference light and the light field are used for interference to achieve demultiplexing processing.

[0103] Spatial division multiplexing generally refers to the spatial division multiplexing of lasers with the same frequency, but it can also be the spatial division of lasers with different frequencies. The above application modes and rules do not limit the basic features of the method and system of the present invention, nor do they limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An angular space-division multiplexing device for optical fiber communication, comprising a transmitting end and a receiving end, characterized in that: at At the transmitting end, at least two lasers are arranged to emit laser beams carrying independent information towards the incident surface of the optical fiber at an angle of incidence less than or equal to the maximum optical fiber incident angle. The spatial angles of the laser beams are different, and the laser beams include their respective spatial angle identifiers and / or spatial phase identifiers; at the receiving end, an optoelectronic device is arranged to receive the laser beams and perform demultiplexing according to the spatial angle identifiers and / or spatial phase identifiers included in the laser beams. At the transmitting end, the bus rotates around the optical fiber axis at the maximum optical fiber incident angle for one week at the laser incident point to form a conical space, and at least two lasers aiming at the incident point are arranged in the conical space. The maximum optical fiber incident angle is the critical angle of total reflection incidence of the optical fiber. At the receiving end, at least two optoelectronic device arrays with a difference in optical path of △L1 are arranged. The optoelectronic device arrays respectively receive the laser light fields with a difference in optical path of △L1. The two-dimensional electrical signals of the optoelectronic device arrays are sent to the demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1) and I2 = F2(△L1), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, and F2 is the demultiplexing function of I2.

2. The angular space division multiplexing device for optical fiber communication according to claim 1, characterized in that: The optoelectronic device at the receiving end is an optoelectronic device array.

3. The angle space division multiplexing device for optical fiber communication according to claim 2, wherein: At least two optoelectronic device arrays with a certain difference in optical path are arranged at the receiving end, and the optoelectronic device arrays are connected to the demultiplexer.

4. An angular space division multiplexing device for optical fiber communication according to claim 3, characterized in that: A partially transparent and reflective mirror is arranged at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays receive light fields with different optical paths.

5. The angle space division multiplexing device for optical fiber communication according to claim 3, characterized in that: An optical fiber splitter is arranged at the receiving end, and its function is to split the laser beam so that different optoelectronic device arrays receive light fields with different optical paths.

6. An angular space division multiplexing device for optical fiber communication according to claim 1 or 2 or 4 or 5, characterized in that: A grating is arranged at the receiving end, and pre-processing before demultiplexing is performed by the grating.

7. An angular space division multiplexing device for optical fiber communication according to claim 6, characterized in that: The grating is a concentric circle grating.

8. An angular space division multiplexing device for optical fiber communication according to claim 1 or 2 or 4 or 5, characterized in that: A reference light source is arranged at the receiving end, and demultiplexing processing is realized by the interference of the reference light and the light field.

9. An angular space division multiplexing device for optical fiber communication according to claim 1 or 2 or 4 or 5, characterized in that: A reference light source is arranged at the transmitting end, and the reference light and the laser beam carrying information are incident on the optical fiber together.

10. An angular space division multiplexing device for optical fiber communication according to claim 1 or 2 or 4 or 5, characterized in that: A tapered optical fiber interface is arranged at the transmitting end, and different laser beams are guided to be incident on the optical fiber by the tapered optical fiber interface.

11. An angular space division multiplexing method for optical fiber communication, characterized in that, The method includes: at the transmitting end, at least two lasers are arranged to emit laser beams carrying independent information towards the incident surface of the optical fiber at an angle of incidence less than or equal to the maximum optical fiber incident angle. The spatial angles of the laser beams are different, and the laser beams include their respective spatial angle identifiers and / or spatial phase identifiers; at the receiving end, an optoelectronic device is arranged to receive the laser beams and perform demultiplexing according to the spatial angle identifiers and / or spatial phase identifiers included in the laser beams. At the transmitting end, the bus rotates around the optical fiber axis at the maximum optical fiber incident angle for one week at the laser incident point to form a conical space, and at least two lasers aiming at the incident point are arranged in the conical space. The maximum optical fiber incident angle is the critical angle of total reflection incidence of the optical fiber. At the receiving end, at least two optoelectronic device arrays with a difference in optical path of △L1 are arranged. The optoelectronic device arrays respectively receive the laser light fields with a difference in optical path of △L1. The two-dimensional electrical signals of the optoelectronic device arrays are sent to the demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1) and I2 = F2(△L1), where I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, and F2 is the demultiplexing function of I2.

12. The angular space division multiplexing method for optical fiber communication according to claim 11, further characterized in that: The optoelectronic device array at the receiving end receives the laser light field and separates different independent information.

13. The angular space division multiplexing method for optical fiber communication according to claim 12, further characterized in that: At the receiving end, there are n + 1 partially transmissive mirrors. The partially transmissive mirrors split the laser beam to form optical path differences of △L1, △L2, ……, △Ln. The optoelectronic device arrays corresponding to different optical path differences respectively receive the light fields with different optical paths. The two-dimensional electrical signals of the optoelectronic device arrays are sent to the demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1, △L2, ……, △Ln), I2 = F2(△L1, △L2, ……, △Ln), In = Fn(△L1, △L2, ……, △Ln). I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

14. The angle space division multiplexing method for optical fiber communication according to claim 12, further characterized in that: At the receiving end, there are n + 1 fiber optic splitters. The fiber optic splitters split the laser beam to form optical path differences of △L1, △L2, ……, △Ln. The optoelectronic device arrays corresponding to different optical path differences respectively receive the light fields with different optical paths. The two-dimensional electrical signals of the optoelectronic device arrays are sent to the demultiplexer for demultiplexing operations. The algorithms are I1 = F1(△L1, △L2, ……, △Ln), I2 = F2(△L1, △L2, ……, △Ln), In = Fn(△L1, △L2, ……, △Ln). I1 is information stream 1, I2 is information stream 2, F1 is the demultiplexing function of I1, F2 is the demultiplexing function of I2, In is information stream n, and Fn is the demultiplexing function of In.

15. A method for angular space division multiplexing in optical fiber communication according to claim 11 or 12 or 13 or 14, further characterized in that: A grating is arranged in the optical path at the receiving end to perform pre-demultiplexing processing on the light field.

16. The angle space division multiplexing method for optical fiber communication according to claim 15, further characterized in that: The concentric circle grating performs pre-demultiplexing processing on the light field.

17. A method for angular space division multiplexing in optical fiber communication according to claim 11 or 12 or 13 or 14, further characterized in that: At the receiving end, demultiplexing processing is achieved by the interference of the reference light and the light field.

18. A method for angular space division multiplexing in optical fiber communication according to claim 11 or 12 or 13 or 14, further characterized in that: A reference light source is arranged at the sending end. The reference light and the laser beam carrying information are incident on the optical fiber together. After exiting at the receiving end, demultiplexing processing is achieved by the interference of the reference light and the light field.

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