WO2016206085A1 - 复用装置、解复用装置、模式控制方法及系统 - Google Patents

复用装置、解复用装置、模式控制方法及系统 Download PDF

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Publication number
WO2016206085A1
WO2016206085A1 PCT/CN2015/082484 CN2015082484W WO2016206085A1 WO 2016206085 A1 WO2016206085 A1 WO 2016206085A1 CN 2015082484 W CN2015082484 W CN 2015082484W WO 2016206085 A1 WO2016206085 A1 WO 2016206085A1
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mode
phase
grating
signal
signals
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PCT/CN2015/082484
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English (en)
French (fr)
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李玉茹
马会肖
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华为技术有限公司
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Priority to CN201580048223.8A priority Critical patent/CN106687837B/zh
Priority to PCT/CN2015/082484 priority patent/WO2016206085A1/zh
Publication of WO2016206085A1 publication Critical patent/WO2016206085A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/34—Optical coupling means utilising prism or grating

Definitions

  • the present invention relates to the field of optical communications, and in particular, to a multiplexing device, a demultiplexing device, a mode control method, and a system.
  • the mode-less mode multiplexing refers to a technique of separately modulating multiple fundamental mode signals into different mode-modes and combining them into one multiplexed signal for transmission.
  • a signal modulated into a mode-less mode may be referred to as a "small mode signal.”
  • each of the N-channel fundamental signals corresponds to a mode-less phase plate, and each of the fundamental mode signals is respectively modulated into a corresponding mode of a small-mode signal by a corresponding small-mode phase plate, and N-channel mode
  • the signal is combined into a multiplexed signal by the same beam splitter to complete the modeless mode multiplexing of the multiple optical signals.
  • a small mode phase plate needs to be separately set for each fundamental mode signal.
  • the required small mode phase plate also increases correspondingly.
  • the multiplexing mode is large, the system is complicated. The precision of the optical path is high and the space is large.
  • Embodiments provide a multiplexing device, a demultiplexing device, a mode control method, and a system.
  • the technical solution is as follows:
  • a multiplexing apparatus comprising: a controller and a phase grating;
  • the controller and the phase grating are electrically connected;
  • the controller is configured to receive incident information corresponding to each of the N fundamental modes, wherein the N fundamental signals are fundamental signals simultaneously incident to the phase grating, and the incident information includes a target mode and an incident angle, N ⁇ 2, and N is an integer;
  • the controller is configured to generate a phase hologram of the phase grating according to respective incident information of the N-channel fundamental signals, and transmit the phase hologram to the phase grating;
  • the phase grating is configured to modulate the N-channel fundamental mode signal into a multiplexed signal according to the phase hologram, wherein the multiplexed signal includes N-way small-mode signals, and the N-way small-mode signals and the The N-channel fundamental signals correspond one-to-one, and the mode of each mode-less mode signal is the target mode of the corresponding fundamental mode signal.
  • the controller is configured to generate, according to the respective incident information of the N-channel fundamental signals, the phase information of the small-mode grating corresponding to each of the N-channel fundamental signals, and according to the N-base Forming a phase hologram of the phase grating by respective corresponding mode-less grating phase information of the mode signals;
  • the fundamental mode signal corresponding to the small mode grating phase information is when the phase grating adjusts the fundamental mode signal to a corresponding small mode signal, the phase The phase information of the grating.
  • the controller is configured to generate the N-channel base according to respective incident information corresponding to the N-channel fundamental signals
  • the mode signals respectively correspond to the mode-less grating phase information
  • a small-mode phase distribution function is generated according to the target mode of the fundamental mode signal
  • a grating phase distribution function is generated according to the incident angle of the fundamental mode signal.
  • the mode-less phase distribution function is a phase distribution function of a target mode corresponding to the fundamental mode signal; the grating phase distribution function is that the phase grating diffracts a fundamental mode signal incident at a corresponding incident angle to The phase distribution function of the phase grating when the incident end face of the phase grating is perpendicular.
  • the controller is configured to perform a corresponding mode of the small-mode grating according to the N-channel fundamental signals Generating the phase hologram of the phase grating, generating composite phase information of the phase grating according to the corresponding small mode grating phase information of the N base mode signals, and generating the composite phase information Performing a holographic calculation to obtain the phase hologram;
  • the composite phase information is expressed as:
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m ( x, y) represents the phase information of the mode-less grating corresponding to the (x, y) point of the m-th fundamental mode signal
  • r m ⁇ (x, y) is the grating corresponding to the m-th fundamental mode signal at the point of (x, y) Phase distribution function
  • It is the mode-less phase distribution function of the (m, y) point corresponding to the m-th fundamental mode signal.
  • the apparatus further includes: a spatial optical power meter; the spatial optical power meter is disposed at the phase An exit end of the grating, and the spatial optical power meter is electrically connected to the controller;
  • the spatial optical power meter is configured to measure a power of each of the small mode signals in a multiplexed signal emitted from an exit end of the phase grating;
  • the controller is configured to determine, according to the measurement result of the spatial optical power meter, the phase hologram of the phase grating according to the corresponding small mode grating phase information of the N-channel fundamental signals,
  • the duty cycle coefficients of the respective N-channel fundamental signals are respectively implemented to achieve power equalization of the N-channel mode signals.
  • the controller is configured to determine, according to the first iteration calculation, the corresponding signal of the N-channel basic mode signal
  • the controller is configured to calculate composite phase information of the phase grating according to the following formula
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T 1 (x, y) is the first iteration calculation
  • the phase grating corresponds to (x, y) Point composite phase information
  • G m (x, y) represents the mode information of the mode-less grating corresponding to the (x, y) point of the m-th fundamental mode signal
  • r m ⁇ (x, y) is at the (x, y) point
  • the controller is further configured to calculate the spatial light when the phase grating modulates the N fundamental mode signals into one multiplexed signal according to a phase hologram obtained by performing holographic calculation on T 1 (x, y)
  • the power meter measures the variance D 1 of the power of the N-channel mode signals obtained;
  • the controller is configured to use ⁇ 1 m as a final duty ratio coefficient corresponding to the m-th fundamental mode signal when the variance D 1 is less than or equal to a preset variance threshold;
  • the controller is configured to perform a second iteration calculation when the variance D 1 is greater than a preset variance threshold.
  • the controller is configured to calculate at a kth iteration, and the phase grating is based on a pair of T k-1 (x, y) when the phase hologram obtained by the holographic calculation modulates the N fundamental mode signals into one multiplexed signal, the respective powers of the N small mode signals are divided by the total power of the multiplexed signals.
  • the controller is configured to calculate composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the composite phase information of the (x, y) point, and ⁇ k m is the m- th fundamental mode signal when the k-th iteration is calculated.
  • the controller is further configured to calculate the spatial light when the phase grating modulates the N fundamental mode signals into one multiplexed signal according to a phase hologram obtained by performing holographic calculation on T k (x, y)
  • the power meter measures the variance D k of the power of the N-way less-mode signals obtained;
  • the controller is configured to use ⁇ k m as a final duty ratio coefficient corresponding to the m-th fundamental mode signal when the variance D k is less than or equal to the variance threshold;
  • the controller is configured to perform a k+1th iteration calculation when the variance D k is greater than the variance threshold.
  • the N-channel mode signals have different grating periods, And satisfying an integer multiple relationship with each other;
  • a demultiplexing apparatus comprising: a routing control unit, a controller, and a phase grating;
  • the controller is electrically connected to the routing control unit and the phase grating respectively;
  • the routing control unit is configured to send, to the controller, diffraction information corresponding to an N-way small-mode signal, where the N-channel small-mode signal is a signal included in a multiplexed signal incident on the phase grating,
  • the diffraction information includes a current mode and a diffraction angle, N ⁇ 2, and N is an integer;
  • the controller is configured to generate a phase hologram of the phase grating according to the diffraction information corresponding to each of the N-channel mode signals, and transmit the phase hologram to the phase grating;
  • the phase grating is configured to demodulate the multiplexed signal into N basic mode signals according to the phase hologram, wherein the N-way small-mode signals are in one-to-one correspondence with the N-way fundamental mode signals, and each of the channels is The angle at which the fundamental mode signal is emitted from the exit end of the phase grating is the diffraction angle of the corresponding small mode signal.
  • the controller is configured to generate the N-channel mode signal according to the diffraction information corresponding to each of the N-channel mode signals when the phase hologram is generated.
  • the mode information of the modeless grating corresponding to the mode signal is when the phase grating adjusts the mode signal to a fundamental mode signal, the phase grating Phase information.
  • the controller is configured to generate the N according to the diffraction information corresponding to each of the N-channel mode signals
  • a mode-less phase distribution function is generated according to the current mode of the mode-less signal
  • a grating phase distribution is generated according to the diffraction angle of the mode-less signal.
  • the mode-less phase distribution function is a phase distribution function of a target mode corresponding to the fundamental mode signal; and the grating phase distribution function is when the phase grating diffracts a vertically-injected small-mode signal to a corresponding diffraction angle The phase distribution function of the phase grating.
  • the controller is configured to perform a corresponding small-mode grating according to the N-channel mode signals
  • the phase information generates the phase hologram of the phase grating
  • the composite phase information of the phase grating is generated according to the corresponding small-mode grating phase information of the N-channel mode signals, and the composite phase information is holographically calculated.
  • the composite phase information is expressed as:
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m ( x, y) represents the mode information of the mode-less grating corresponding to the (x, y) point of the m-th mode-less signal
  • r m ⁇ (x, y) is at the point of (x, y)
  • the m-th mode of the mode signal corresponds to Grating phase distribution function
  • a mode-less phase distribution function corresponding to the (x, y) point for the mth mode is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m ( x, y) represents the mode information of the mode-less grating corresponding to the (x, y) point of the m-th mode
  • the device further includes: a spatial optical power meter; the spatial optical power meter is disposed at the phase An exit end of the grating, and the spatial optical power meter is electrically connected to the controller;
  • the spatial optical power meter is configured to measure respective powers of the N fundamental mode signals emitted from an exit end of the phase grating;
  • the controller is configured to determine, according to the measurement result of the spatial optical power meter, a phase hologram of the phase grating according to the corresponding small mode grating phase information of the N-channel mode signals,
  • the N-channel mode signals respectively have corresponding duty cycle coefficients to achieve power equalization of the N-channel fundamental mode signals.
  • the controller is configured to determine, according to the first iteration calculation, the N-channel mode-less signal
  • the controller is configured to calculate composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the (x, y) point Composite phase information
  • G m (x, y) represents the mode information of the small-mode grating corresponding to the (x, y) point of the m-th mode-less signal
  • r m ⁇ (x, y) is at the (x, y) point
  • the grating phase distribution function corresponding to the m-th mode of the mode signal
  • a mode-less phase distribution function corresponding to the (x, y) point of the m-th mode-less signal
  • the controller is further configured to calculate the spatial light when the phase grating demodulates the multiplexed signal into an N-way fundamental mode signal according to a phase hologram obtained by performing holographic calculation on T 1 (x, y)
  • the power meter measures the variance D 1 of the power of the N fundamental mode signals obtained;
  • the controller for, when D 1 is smaller than the variance of the variance equal to a preset threshold value, ⁇ 1 m as a final duty factor mode signal corresponding to at least the m-th path;
  • the controller is configured to perform a second iteration calculation when the variance D 1 is greater than a preset variance threshold.
  • the controller is configured to calculate at a kth iteration, and the phase grating is based on a pair of T k-1 (x, y) a phase hologram obtained by holographic calculation, when demodulating the multiplexed signal into N fundamental mode signals, inversely dividing the power of the N fundamental modes by the total power of the multiplexed signal Perform normalization processing to obtain the duty ratio coefficients of the N-way small-mode signals when the k-th iteration is calculated; T k-1 (x, y) is the k-1th iteration calculation, the phase The grating corresponds to the composite phase information of the (x, y) point; k ⁇ 2 and k is an integer;
  • the controller is configured to calculate composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the composite phase information of the (x, y) point
  • ⁇ k m is the m- th mode when the k-th iteration is calculated.
  • the controller is further configured to calculate the spatial light when the phase grating demodulates the multiplexed signal into an N-way fundamental mode signal according to a phase hologram obtained by performing holographic calculation on T k (x, y)
  • the power meter measures the variance D k of the power of the N fundamental mode signals obtained;
  • the controller is configured to use ⁇ k m as a final duty ratio coefficient corresponding to the m-th mode-less signal when the variance D k is less than or equal to the variance threshold;
  • the controller is configured to perform a k+1th iteration calculation when the variance D k is greater than the variance threshold.
  • the N-channel mode signals have different grating periods, And satisfying an integer multiple relationship with each other;
  • a mode control method for use in a multiplexing device, the multiplexing device comprising: a controller and a phase grating, the method comprising:
  • the controller receives incident information corresponding to each of the N fundamental modes, wherein the N fundamental signals are fundamental signals simultaneously incident on the phase grating, and the incident information includes a target mode and an incident angle, N ⁇ 2, and N is an integer;
  • the controller generates a phase hologram of the phase grating according to respective incident information of the N-channel fundamental signals, and transmits the phase hologram to the phase grating, according to the phase grating, according to the phase
  • the hologram modulates the N-channel fundamental mode signal into a multiplexed signal, wherein the multiplexed signal includes N-way small-mode signals, and the N-way small-mode signals are in one-to-one correspondence with the N-way fundamental mode signals, and each path
  • the mode of the mode-less signal is the target mode of the corresponding fundamental mode signal.
  • the generating a phase hologram of the phase grating according to the corresponding incident information of the N-channel fundamental signals includes:
  • the controller generates phase information of the small mode grating corresponding to each of the N base mode signals according to the corresponding incident information of the N base mode signals, and generates a phase of the small mode grating corresponding information according to the N basic mode signals a phase hologram of the phase grating;
  • the fundamental mode signal corresponding to the small mode grating phase information is when the phase grating adjusts the fundamental mode signal to a corresponding small mode signal, the phase Phase information of the bit raster.
  • the generating the N basic mode signals according to the respective incident information of the N basic mode signals respectively Mode grating phase information including:
  • the controller For each fundamental mode signal, the controller generates a mode-less phase distribution function according to a target mode of the fundamental mode signal, generates a grating phase distribution function according to an incident angle of the fundamental mode signal, and according to the mode-less phase distribution a function and the grating phase distribution function to generate small mode grating phase information of the fundamental mode signal;
  • the mode-less phase distribution function is a phase distribution function of a target mode corresponding to the fundamental mode signal; the grating phase distribution function is that the phase grating diffracts a fundamental mode signal incident at a corresponding incident angle to The phase distribution function of the phase grating when the incident end face of the phase grating is perpendicular.
  • phase holograms including:
  • the controller generates composite phase information of the phase grating according to the corresponding mode-less grating phase information of the N-channel fundamental signals, and performs holographic calculation on the composite phase information to obtain the phase hologram;
  • the composite phase information is expressed as:
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m ( x, y) represents the phase information of the mode-less grating corresponding to the (x, y) point of the m-th fundamental mode signal
  • r m ⁇ (x, y) is the grating corresponding to the m-th fundamental mode signal at the point of (x, y) Phase distribution function
  • It is the mode-less phase distribution function of the (m, y) point corresponding to the m-th fundamental mode signal.
  • the multiplexing device further includes: a spatial optical power meter; the method further includes:
  • the controller generates the phase information of the small-mode grating corresponding to each of the N-channel fundamental signals
  • the phase hologram of the phase grating is determined according to the measurement result of the spatial optical power meter, and the duty ratio coefficients corresponding to the N basic mode signals are determined by iterative calculation to realize the N mode small mode signal Power balance.
  • the duty cycle factor including:
  • the controller calculates composite phase information of the phase grating according to the following formula
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T 1 (x) is the composite of the (x, y) point when the first iteration is calculated.
  • Phase information G m (x) represents the mode information of the mode-less grating corresponding to the (x, y) point of the m-th fundamental mode signal
  • r m ⁇ (x, y) is the (m, y) point, the m-th fundamental mode
  • the controller calculates the spatial optical power meter measurement when the phase grating modulates the N fundamental mode signals into one multiplexed signal according to the phase hologram obtained by performing holographic calculation on T 1 (x, y) the N-way power mode signal less variance of D 1;
  • the controller uses ⁇ 1 m as the final duty cycle coefficient corresponding to the mth fundamental mode signal;
  • the controller When the variance D 1 is greater than a preset variance threshold, the controller performs a second iteration calculation.
  • the duty cycle factor including:
  • the phase grating modulates the N fundamental mode signals into one multiplexed signal according to a phase hologram obtained by holographic calculation of T k-1 (x, y), the controller And normalizing the inverse power of the power of the N-channel mode signals by the total power of the multiplexed signals, and obtaining the duty ratio coefficients of the N-channel fundamental signals when calculating the k-th iteration;
  • T k-1 (x, y) is calculated for the k-1th iteration
  • the phase grating corresponds to composite phase information of the (x, y) point; k ⁇ 2 and k is an integer;
  • the controller calculates composite phase information of the phase grating according to the following formula
  • T k (x, y) is the k th iteration, corresponding to the phase grating (x, y) in the complex phase information dots, [alpha] m k is the k th iteration, the m-th mode signal roadbed Corresponding duty cycle coefficient;
  • the controller calculates the spatial optical power meter measurement when the phase grating modulates the N fundamental mode signals into one multiplexed signal according to a phase hologram obtained by performing holographic calculation on T k (x, y) The variance of the power of the N-way less-mode signals D k ;
  • the controller uses ⁇ k m as the final duty ratio coefficient corresponding to the mth fundamental mode signal;
  • the controller When the variance of the variance D k is larger than the threshold value, the controller performs the first iteration k + 1 is calculated.
  • the N-channel mode signals corresponding to different grating periods are different, And satisfying an integer multiple relationship with each other;
  • a mode control method for use in a demultiplexing apparatus, the demultiplexing apparatus comprising: a routing control unit, a controller, and a phase grating, the method comprising:
  • the controller receives diffraction information corresponding to the N-way small-mode signals sent by the routing control unit, where the N-channel mode-less signals are signals included in a multiplexed signal incident on the phase grating, and the diffraction information Including the current mode and the diffraction angle, N ⁇ 2, and N is an integer;
  • the controller generates a phase hologram of the phase grating according to the diffraction information corresponding to each of the N-channel mode signals, and transmits the phase hologram to the phase grating, according to the phase grating
  • the hologram demodulates the multiplexed signal into N fundamental mode signals, the N way few analog signals
  • the number is in one-to-one correspondence with the N-way fundamental mode signals, and an angle at which each of the fundamental mode signals is emitted from an exit end of the phase grating is a diffraction angle of a corresponding small-mode signal.
  • the generating a phase hologram of the phase grating according to the diffraction information corresponding to each of the N-channel mode signals comprises:
  • the controller generates, according to the diffraction information corresponding to each of the N-channel mode signals, the phase information of the small-mode grating corresponding to the N-channel mode signals, and according to the mode-corresponding phase of the N-channel mode signals Information generating a phase hologram of the phase grating;
  • the mode information of the modeless grating corresponding to the mode signal is when the phase grating adjusts the mode signal to a fundamental mode signal, the phase grating Phase information.
  • the generating, by the respective diffraction information corresponding to the N-channel mode signals, generating the N-channel mode signals respectively Low-mode grating phase information including:
  • the controller For each mode of the small mode signal, the controller generates a mode-less phase distribution function according to the current mode of the mode-less signal, generates a grating phase distribution function according to the diffraction angle of the mode-less signal, and according to the mode-less phase distribution a function and the grating phase distribution function generate the mode-less grating phase information of the mode-less signal;
  • the mode-less phase distribution function is a phase distribution function of a target mode corresponding to the fundamental mode signal; and the grating phase distribution function is when the phase grating diffracts a vertically-injected small-mode signal to a corresponding diffraction angle The phase distribution function of the phase grating.
  • the generating the phase according to the corresponding small mode grating phase information of the N-channel mode signals including:
  • the controller generates composite phase information of the phase grating according to the corresponding small mode grating phase information of the N-channel mode signals, and performs holographic calculation on the composite phase information to obtain the phase hologram;
  • the composite phase information is expressed as:
  • a> 0, (x, y) is the incident end surface of the phase grating coordinates
  • T (x, y) corresponding to said phase grating (x, y) of the complex phase information dots
  • G m ( x, y) represents the mode information of the mode-less grating corresponding to the (x, y) point of the m-th mode-less signal
  • r m ⁇ (x, y) is at the point of (x, y)
  • the m-th mode of the mode signal corresponds to Grating phase distribution function
  • a mode-less phase distribution function corresponding to the (x, y) point for the mth mode.
  • the demultiplexing apparatus further includes: a spatial optical power meter; the method further includes:
  • the controller generates a phase hologram of the phase grating according to the corresponding small mode grating phase information of the N-channel mode signals, and determines the N by iterative calculation according to the measurement result of the spatial optical power meter
  • the duty cycle coefficients of the respective paths of the less-mode signals are used to achieve power equalization of the N-channel fundamental signals.
  • the determining, according to the measurement result of the spatial optical power meter, determining, by using an iterative calculation, each of the N small mode signals Corresponding duty cycle coefficients including:
  • the controller calculates composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the (x, y) point the complex phase information
  • G m (x, y) represents the m-th path few mode signal corresponding to the (x, y) less mode gratings phase information point
  • r m ⁇ (x, y ) of (x, y) at a point the grating phase distribution function corresponding to the m-th mode of the mode signal, a mode-less phase distribution function corresponding to the (x, y) point of the m-th mode-less signal;
  • the controller calculates the spatial optical power meter measurement when the phase grating demodulates the multiplexed signal into N fundamental mode signals according to a phase hologram obtained by performing holographic calculation on T 1 (x, y) The variance of the power of the N-way fundamental mode signal D 1 ;
  • the controller uses ⁇ 1 m as the final duty ratio coefficient corresponding to the m-th mode-less signal;
  • the controller When the variance D 1 is greater than a preset variance threshold, the controller performs a second iteration calculation.
  • the determining, according to the measurement result of the spatial optical power meter, determining, by using an iterative calculation, the N-channel small-mode signals Corresponding duty cycle coefficients including:
  • the phase grating modulates the multiplexed signal into N fundamental mode signals according to a phase hologram obtained by performing holographic calculation on T k-1 (x, y), the controller pair
  • the power of each of the N fundamental modes is divided by the inverse of the total power of the multiplexed signal, and the duty ratio of each of the N small analog signals is obtained when the kth iteration is calculated;
  • the phase grating corresponds to the composite phase information of the (x, y) point;
  • k ⁇ 2 and k is an integer;
  • the controller calculates composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the composite phase information of the (x, y) point
  • ⁇ k m is the m- th mode when the k-th iteration is calculated.
  • the controller calculates the spatial optical power meter measurement when the phase grating demodulates the multiplexed signal into N fundamental mode signals according to a phase hologram obtained by performing holographic calculation on T k (x, y) The variance of the power of the N fundamental mode signals D k ;
  • the controller uses ⁇ k m as the final duty ratio coefficient corresponding to the m-th mode-less signal;
  • the controller When the variance of the variance D k is larger than the threshold value, the controller performs the first iteration k + 1 is calculated.
  • the N-channel small-mode signals have different grating periods, And satisfying an integer multiple relationship with each other;
  • a mode control system comprising:
  • the controller receives the incident information corresponding to each of the N fundamental modes, generates a phase hologram of the phase grating according to the corresponding incident information of the N fundamental signals, and transmits the phase hologram to the phase grating, and the phase grating according to the phase hologram
  • the sub-module signal is modulated into one multiplexed signal, and the multiplexed signal includes N-way small-mode signals, and the N-way less-mode signals are in one-to-one correspondence with the N-channel fundamental mode signals, and the mode of each of the less-mode signals is the corresponding fundamental mode signal.
  • the modulation and multiplexing of the multi-channel fundamental signals are performed by the same grating device.
  • the mode control system shown in the embodiment of the present invention only needs to increase the incident angle and the target mode to expand the channel, thereby facilitating the expansion of the optical interconnect capacity.
  • FIG. 1 is a structural diagram of a mode control system according to an embodiment of the present invention.
  • FIG. 2A is a structural diagram of a mode-less signal generation and modulation apparatus according to an embodiment of the present invention.
  • 2B is a schematic diagram of incident light signals according to an embodiment of the present invention.
  • 2C is a phase distribution diagram of a phase grating according to an embodiment of the present invention.
  • 2D is a phase hologram provided by an embodiment of the present invention.
  • 2E is a structural diagram of an internal unit of a controller according to an embodiment of the present invention.
  • 3A is a structural diagram of a multiplexing device according to an embodiment of the present invention.
  • FIG. 3B is a structural diagram of a controller according to an embodiment of the present invention.
  • 3C is a comparison diagram of experimental measurements and simulation effects of a five-mode phase grating provided by an embodiment of the present invention.
  • FIG. 3D is a phase hologram of a phase grating capable of performing modulation and multiplexing of five mode signals of LP 21 , LP 11a , LP 01 , LP 11b, and LP 31 according to an embodiment of the present invention
  • FIG. 4A is a structural diagram of a demultiplexing apparatus according to an embodiment of the present invention.
  • FIG. 4B is a schematic diagram of routing control according to an embodiment of the present invention.
  • 4C is a schematic diagram of another routing control according to an embodiment of the present invention.
  • 4D is a schematic diagram of a mode exchange provided by an embodiment of the present invention.
  • FIG. 5 is a flowchart of a mode control method according to an embodiment of the present invention.
  • FIG. 6 is a flowchart of a mode control method according to an embodiment of the present invention.
  • FIG. 1 shows a structural diagram of a mode control system 100 according to an embodiment of the present invention.
  • the mode control system 100 can include: a multiplexing device 110, a demultiplexing device 120, N signal transmitting units 130, and N signal receiving units 140;
  • the multiplexing device 110 includes a first controller 112 and a first phase grating 114, and the first controller 112 and the first phase grating 114 are electrically connected;
  • the demultiplexing device 120 includes a routing control unit 122 and a second controller. 124 and the second phase grating 126, and the second controller 124 and the routing control unit 122 and the second phase grating 126 are electrically connected, respectively.
  • Each of the N signal transmitting units 130 transmits a fundamental mode signal to the first phase grating through different incident angles, and the first phase grating 114 modulates and multiplexes the fundamental mode signals respectively transmitted by the N signal transmitting units 130 into one multiplexed signal. And emitting from the exit end, the multiplexed signal is transmitted through the space and then incident on the second phase grating 126; the second phase grating 126 demodulates the multiplexed signal into N fundamental mode signals, and demodulates the N fundamental mode signals. The light is emitted at different diffraction angles and received by the N signal receiving units 140, respectively.
  • the incident angle refers to an angle between the incident direction of the fundamental mode signal and the vertical line of the incident end surface of the first phase grating.
  • the diffraction angle refers to the exit direction of the fundamental mode signal and the exit end face of the second phase grating. The angle between the vertical lines.
  • the pattern can be understood as the distribution of the field of light waves in space.
  • the amount of the characteristic is the intensity, the phase, the frequency of the phase change, and the like. Therefore, different modes can be understood to be spatially different field distribution forms. Since the interference between the small-mode signals of multiple modes with orthogonality is small, it is possible to pass the same physical Channel transmission, thereby increasing the transmission capacity of the physical channel.
  • the mode control system shown in the embodiment of the present invention only one phase grating is needed for the transmitting end of the optical signal, that is, a plurality of fundamental mode signals can be respectively modulated into different small-mode signals and combined into one multiplexed signal, and the optical signal is synthesized.
  • the receiving end also needs only one phase grating to demultiplex one multiplexed signal into multiple fundamental mode signals and emit them from different diffraction angles respectively. It is not necessary to set an independent small mode phase plate for each fundamental mode signal.
  • the phase conversion is performed, the accuracy of the optical path is low, and the system is simple in structure and small in space.
  • the mode control system shown in the embodiment of the present invention only needs to increase the incident angle and the target mode to expand the channel, thereby facilitating the expansion of the optical interconnection. Capacity.
  • FIG. 2A is a structural diagram of a mode-less signal generation and modulation apparatus according to an embodiment of the present invention.
  • the mode-less signal generation and modulation device can be used to modulate a fundamental mode signal into a small mode signal of a certain target mode.
  • the mode-less signal generation and modulation device includes a controller 210 and a phase grating 220.
  • the input signal is a fundamental mode signal, and the angle of incidence of the fundamental mode signal and the desired target mode to which it is adjusted.
  • the fundamental mode signal is directly incident on the phase grating, and the corresponding incident angle and the target mode are input to the controller.
  • the output signal is a small mode signal that is modulated onto the target mode.
  • the controller Assuming that the fundamental mode signal is incident on the phase grating at the incident angle ⁇ , and the intended target mode is the LP im mode, the controller generates a phase hologram according to the angle and the target mode LP im and transmits the phase hologram to the phase grating.
  • the phase grating is controlled to adjust the phase information.
  • the fundamental mode signal is incident on the adjusted phase grating, the small mode signal modulated to the LP im mode can be output.
  • the step of modulating the fundamental mode signal by the modeless signal generation and modulation apparatus can be as follows:
  • Step 1 The controller determines a mode-less phase distribution function according to the target mode to which the input fundamental mode signal needs to be modulated.
  • the fundamental mode signal corresponding to the mode-less phase distribution function is phase information of the target mode corresponding to the fundamental mode signal.
  • a plane rectangular coordinate system is established on the incident end face of the phase grating, and a mode electric field of a small mode signal can usually be expressed as E A is a general Gaussian or other electric field expression, and (x, y) represents a coordinate on a cross section perpendicular to the transmission direction of the mode-less signal, wherein That is, the mode-less phase distribution function of the mode-less signal corresponding to the (x, y) point, corresponding to the different mode-signal
  • the embodiment of the present invention can be determined according to a target mode of a fundamental mode signal
  • Step 2 The controller determines a grating phase distribution function according to the input incident angle.
  • the grating phase distribution function of the fundamental mode signal is a phase distribution function of the phase grating when a phase grating diffracts a fundamental mode signal incident at a corresponding incident angle to a direction perpendicular to the incident end face of the phase grating.
  • the phase grating may perform phase conversion only at a certain angle between the x-axis and the y-axis in the plane rectangular coordinate system in the above step 1.
  • (x, y) The grating phase corresponding to the coordinate point is expressed as:
  • d is the grating period of the phase grating
  • r is the frequency of the phase change, and represents the phase change amount on the unit coordinate, also called the phase period
  • i is an imaginary symbol.
  • d is uniquely determined by the fundamental mode signal incident angle ⁇ .
  • the period information may be acquired online according to the incident angle ⁇ of the input fundamental mode signal, or the appropriate period information and its corresponding incident angle may be selected according to the characteristics of the grating to form a table, and the table is stored in the controller.
  • the grating period is obtained by looking up the table by identifying the incident angle ⁇ of the fundamental mode signal.
  • a bundle of fundamental mode signals 21 is incident on the incident end face 22 of the phase grating at an incident angle ⁇ and is emitted at an angle perpendicular to the incident end face 22.
  • the effective size of the phase grating be 2cm*2cm
  • all the gratings are divided into 1025*1025 parts
  • the etching precision is 2/1025 (the etching precision is mainly determined by the process, which represents the minimum amount of phase change that can be characterized). It is known that there are 12 minimum units in a grating period, that is, a grating of one period is divided into 12 parts.
  • the phase grating is a blazed grating, and the blazed grating illuminates only the incident fundamental mode signal in the x-axis direction in the incident end face, and the phase grating is blazed when the fundamental mode signal incident at 1.83° is performed.
  • the phase profile can be as shown in Figure 2C.
  • the incident angle ⁇ can be characterized by different transmission channels (or different input ports), and each incident angle corresponds to one signal, so that the correspondence between the channel number and the period information can also be directly stored.
  • Step 3 The controller generates a phase hologram of the phase grating according to the generated small mode phase distribution function and the grating phase distribution function.
  • T(x, y) is the phase information of the phase grating at the (x, y) point.
  • the phase hologram of the phase grating can be obtained by holographic calculation.
  • the phase hologram contains both the information of the small mode and the information of the blazed grating.
  • Step 4 The controller updates the generated phase hologram to the phase grating.
  • the fundamental mode signal When the fundamental mode signal is incident on the phase grating, it can be modulated into a mode-less mode signal, and the diffraction direction of the mode signal is The incident end face of the phase grating is perpendicular.
  • the process of generating the phase hologram of the corresponding phase grating is illustrated by taking the mode of the LP 11 mode as an example.
  • the combination of HE l-1m and EH l+1m satisfying Maxwell's equations is a linear polarization mode, which is denoted as LP lm mode, where l is an l-order Bessel function and m is l-order.
  • LP 11 is the first root of the first order corresponding to the first Bessel function in Maxwell's equations in the fiber waveguide. According to the characteristics of its own mode field:
  • the mode field is symmetric about the y-axis and is called the LP 11a mode.
  • the mode field is symmetric about the x-axis and is called the LP 11b mode.
  • the expression on the phase can be expressed as:
  • the phase change frequency of the phase grating is r, where (x, y) is the coordinate on the incident end face of the phase grating, and according to the etching precision of the grating, each different coordinate point (x, y) is taken.
  • Phase value The phase hologram obtained by modulating the fundamental mode signal into the LP 11a mode signal and diffracting the LP 11a mode signal into a direction perpendicular to the incident end face is obtained.
  • the effective size of the phase grating is 2cm*2cm, the total grating is divided into 1025*1025 parts, and r is taken as an example.
  • the phase hologram obtained by holographic calculation can be as shown in Fig. 2D.
  • the step of generating the phase hologram according to the incident angle and the target mode and inputting the phase grating may be performed by the controller by executing the pre-stored program code, or may be logically operated by the operation unit included in the controller. carried out.
  • the controller 210 may include a small mode phase generating unit 211, a grating phase generating unit 212, and a phase hologram generating unit 213, and a modeless phase generating unit 211 receives the input target mode, and determines the mode-less phase according to the target mode, the grating phase generating unit 212 receives the input incident angle, and determines the grating phase according to the incident angle, and the phase hologram generating unit 213 generates the phase according to the mode-less phase and the grating phase.
  • the phase hologram of the grating, the internal unit structure diagram of the controller 210 can be as shown in Fig. 2E.
  • FIG. 3A shows a structural diagram of a multiplexing device according to an embodiment of the present invention.
  • the multiplexing device may be the multiplexing device 110 in the system shown in FIG. 1.
  • the multiplexing device may include: a controller 310 and a phase grating 320;
  • the controller 310 and the phase grating 320 are electrically connected;
  • the controller 310 is configured to receive incident information corresponding to each of the N fundamental modes, where the N fundamental signals are fundamental signals that are simultaneously incident to the phase grating 320, and the incident information includes a target mode and an incident angle.
  • N ⁇ 2, and N is an integer;
  • the controller 310 is configured to generate a phase hologram of the phase grating 320 according to the corresponding incident information of the N-channel fundamental signals, and transmit the phase hologram to the phase grating 320;
  • the phase grating 320 is configured to modulate the N-channel fundamental mode signal into a multiplexed signal according to the phase hologram, where the multiplexed signal includes N-way small-mode signals, and the N-way small-mode signals and The N-channel fundamental signals are in one-to-one correspondence, and the mode of each of the small-mode signals is the target mode of the corresponding fundamental mode signal.
  • the phase grating can be a blazed grating, and the grating can directly introduce the phase hologram generated by the controller through a mathematical algorithm into a spatial light modulator (English full name: Spatial Light Modulator, Abbreviation: SLM), becomes a tunable grating device.
  • a spatial light modulator English full name: Spatial Light Modulator, Abbreviation: SLM
  • the phase grating updates its phase according to the received phase hologram sent by the controller, and the subsequent N signal transmitting units respectively send a fundamental mode signal to the phase grating through different incident angles.
  • the phase grating respectively modulates the N fundamental mode signals into corresponding mode small mode signals, and synthesizes the N path small mode signals generated by the modulation into one multiplexed signal, and modulates and multiplexes the multiple fundamental mode signals. Both are done by the same grating device.
  • the controller 310 is configured to generate phase information of the small-mode grating corresponding to the N-channel fundamental signals according to respective incident information of the N-channel fundamental signals when the phase hologram is generated, and And generating a phase hologram of the phase grating according to the corresponding small mode grating phase information of the N base mode signals.
  • the phase information of the small mode grating corresponding to the fundamental mode signal is phase information of the phase grating when the phase grating adjusts the fundamental mode signal to a corresponding small mode signal.
  • the controller 310 is configured to generate, according to the respective incident information of the N-channel fundamental signals, the phase information of the small-mode grating corresponding to each of the N-channel fundamental signals, Generating a target mode of the signal to generate a mode-less phase distribution function, generating a grating phase distribution function according to an incident angle of the fundamental mode signal, and generating the fundamental mode signal according to the mode-less phase distribution function and the grating phase distribution function Mode grating phase information.
  • the mode-less phase distribution function is a phase distribution function of a target mode corresponding to the fundamental mode signal;
  • the grating phase distribution function is a phase grating that diffracts a fundamental mode signal incident at a corresponding incident angle to an incidence of the phase grating
  • the phase distribution function of the phase grating when the end face is perpendicular.
  • the controller 310 is configured to: when the phase hologram of the phase grating is generated according to the corresponding small mode grating phase information of the N-channel fundamental signals, respectively, according to the N-channel fundamental signals respectively corresponding to each Forming grating phase information to generate composite phase information of the phase grating, and performing holographic calculation on the composite phase information to obtain the phase hologram;
  • the composite phase information is expressed as:
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m (x , y) represents the phase information of the mode-less grating corresponding to the (x, y) point of the m-th fundamental mode signal
  • r m ⁇ (x, y) is the grating phase corresponding to the m-th fundamental mode signal at the point (x, y) Distribution function
  • It is the mode-less phase distribution function of the (m, y) point corresponding to the m-th fundamental mode signal.
  • the multiplexing device is an optical signal processing device that modulates N fundamental signals that are incident at different angles onto N different small-mode signals, and multiplexes them into one signal.
  • each incident angle is equivalent to one channel
  • N channels correspond to N incident angles
  • target modes 1 of the N fundamental mode signals are corresponding to the target mode 2
  • the controller After the target mode N is input to the controller, the controller generates a phase hologram of the blazed grating based on the information and inputs it to the blazed grating to update the phase information of the blazed grating.
  • the blazed grating modulates the N fundamental mode signals onto N different small-mode signals, and multiplexes them into one signal and outputs them, which completes the modulation of N different modes. Reuse. Since there is orthogonality between different modes of the small mode signal, the multiplexed signals do not interfere with each other and can be transmitted on the same channel, thereby increasing the transmission capacity of the channel.
  • the step of the controller generating the phase hologram can be as follows:
  • step 1 the controller generates respective corresponding mode-mode phase distribution functions and grating phase distribution functions by using the input target mode and the incident angle of each of the fundamental mode signals, respectively, and generates corresponding small-mode grating phase information.
  • the incident angles of the fundamental mode signal 1 to the fundamental mode signal N are ⁇ 1 , ⁇ 2 , ..., ⁇ N , respectively, and the corresponding period information is uniquely determined according to the incident angle as d 1 , d 2 , ..., d N
  • the method of acquiring the period information according to the incident angle is the same as the step 2 in the embodiment shown in FIG. 2A.
  • the targets to be modulated by the respective fundamental mode signals are LP 11 , LP 12 , ..., LP 1N , respectively . Then, it can be determined that the mode-less phase distribution function and the grating phase distribution function corresponding to each fundamental mode signal are respectively recorded as:
  • Step 2 The controller generates a phase hologram of the blazed grating according to the phase information of the small mode grating corresponding to each of the fundamental mode signals.
  • phase information of the small mode grating corresponding to each basic mode signal is entered.
  • Line superposition can produce composite phase information of the phase grating, and its mathematical expression can be recorded as:
  • the phase hologram of the phase grating can be obtained by holographic calculation.
  • the phase hologram contains information on each mode and its corresponding blazed grating information.
  • step 3 the controller passes the phase hologram to the phase grating and updates its phase information.
  • the step of generating a phase hologram according to the target mode and the incident angle corresponding to each of the fundamental mode signals may be implemented by a controller executing a pre-stored software code, or may be generated by a logic operation by each operation unit included in the controller. .
  • the controller 310 when the controller 310 is composed of N control units (ie, 310a1, . . . , 310ai, . . . , 310aN in FIG. 3B) and one phase hologram generating unit 310b.
  • the N control units respectively correspond to the fundamental signals of the N-channel incident.
  • Each control unit is composed of a small mode phase generating unit, a grating phase generating unit and a modeless grating phase generating unit. The relationship between the units in the control unit is described by taking the control unit i as an example.
  • the target mode i and the incident angle i corresponding to the i-th signal are input to at least the mode phase generating unit 310ai1 and the grating phase generating unit 310ai2, respectively.
  • the mode phase i and the grating phase i; the generated mode-out phase i and the grating phase i are transmitted to at least the mode grating phase generating unit 310ai3 to generate the mode-less grating phase information i.
  • the mode-less grating phase information i is transmitted to the phase hologram generating unit 310b together with the N-1 small-mode grating phase information generated by the other N-1 control units to generate a phase hologram of the phase grating.
  • the multiplexing device shown in the embodiment of the present invention may further include a spatial optical power meter 330 disposed at an exit end of the phase grating 320, and the spatial optical power meter 320 and the control The device 310 is electrically connected;
  • the spatial optical power meter 330 is configured to measure power of each of the small mode signals in the multiplexed signal emitted from the exit end of the phase grating;
  • the controller 310 is configured to perform an iterative calculation according to the measurement result of the spatial optical power meter 330 when the phase hologram of the phase grating is generated according to the corresponding small mode grating phase information of the N fundamental signals. Determining respective duty cycle coefficients of the N way fundamental mode signals to achieve power equalization of the N way mode signals.
  • the controller 310 is further configured to calculate composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the (x, y) point the complex phase information
  • G m (x, y) represents the m-th subgrade analog signal corresponding to the (x, y) less mode gratings phase information point
  • the grating phase distribution function corresponding to the mth fundamental mode signal It is the mode-less phase distribution function of the (m, y) point corresponding to the m-th fundamental mode signal.
  • the controller 310 is further configured to calculate the spatial light when the phase grating obtains a phase hologram according to a holographic calculation of T 1 (x, y) to modulate the N fundamental mode signals into one multiplexed signal.
  • the power meter measures the variance D 1 of the obtained power of the N-channel mode signal;
  • the controller 310 is configured to use ⁇ 1 m as a final duty ratio coefficient corresponding to the m-th fundamental mode signal when the variance D 1 is less than or equal to a preset variance threshold;
  • the controller 310 is configured to perform a second iteration calculation when the variance D 1 is greater than a preset variance threshold.
  • the controller 310 is configured to calculate at the kth iteration, and the phase grating obtains a phase hologram according to holographic calculation of T k-1 (x, y) to modulate the N fundamental mode signals into one multiplexing
  • the respective powers of the N-channel mode signals are divided by the total power of the multiplexed signals, and the inverse ratio of the obtained results is normalized, and when the k-th iteration calculation is obtained, the N The duty cycle coefficient of each of the submodule signals;
  • T k-1 (x, y) is the composite phase information of the (x, y) point when the k-1th iteration is calculated;
  • k ⁇ 2 and k is an integer;
  • the controller is configured to calculate composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the composite phase information of the (x, y) point, and ⁇ k m is the m- th fundamental mode signal when the k-th iteration is calculated.
  • the controller 310 is further configured to calculate the spatial light when the phase grating obtains a phase hologram according to a holographic calculation of T k (x, y) to modulate the N fundamental mode signals into one multiplexed signal.
  • the power meter 330 measures the variance D k of the obtained power of the N-channel mode signal;
  • the controller 310 is configured to use ⁇ k m as the final duty ratio coefficient corresponding to the mth fundamental mode signal when the variance D k is less than or equal to the variance threshold;
  • the controller 310 is configured to perform a k+1th iteration calculation when the variance D k is greater than the variance threshold.
  • phase grating of the present invention the composite phase information is obtained by directly adding the phases of the small-mode gratings corresponding to the respective fundamental mode signals. In most cases, the generated multiplexed signals are directly superimposed and their modes are respectively The power balance between the two is not very ideal.
  • the superposition is optimized by introducing the duty ratio ⁇ m of the phase grating to complete the power balance between the modes after multiplexing or demultiplexing.
  • the ⁇ m coefficient satisfies the normalization condition, and the steps of optimizing ⁇ m to achieve power equalization are as follows:
  • Step 1 the controller initializes ⁇ m: setting the duty ratio ⁇ m coefficients of all modes are the same;
  • Step 2 According to the initialized duty cycle system, the phase hologram is generated by the phase expression superimposed by the weighting coefficients, and the phase information of the phase grating is updated.
  • Step 3 The N-channel fundamental signal is incident on the updated phase grating, and the power of each of the reduced-mode signals in the output multiplexed signal is measured, and the variance is calculated.
  • Step 4 Determine whether the variance is less than a threshold. If the threshold is less than the threshold, the set of coefficients is the final coefficient. Further, the phase of the corresponding phase grating is the final phase information. Otherwise, go to step 5.
  • Step 5 taking the inverse of the power of the modeless signal of each mode by the inverse of the total power, a set of new duty cycle coefficients can be obtained. Perform step 2 according to the new duty cycle factor.
  • the grating periods corresponding to the N-channel mode signals are different, and the integer multiple relationship is satisfied with each other;
  • the relationship of integer multiples is satisfied between the respective periods, that is, the distance between the incident positions of the respective fundamental mode signals is equal when the phase grating is operated. Further, it is to make the intervals between the channels uniform, so that the interference between the channels is more even, thereby improving the transmission performance.
  • the multiplexing device shown in the embodiment of the present invention receives the incident information corresponding to each of the N fundamental modes by the controller, and generates a phase hologram of the phase grating according to the corresponding incident information of the N fundamental signals, and The phase hologram is transmitted to the phase grating, and the phase grating modulates the N fundamental mode signal into a multiplexed signal according to the phase hologram, and the multiplexed signal includes N small mode signals, and the N small mode signals correspond to the N fundamental mode signals one by one.
  • the mode of each mode of the small mode signal is the target mode of the corresponding fundamental mode signal, and the modulation and multiplexing of the multipath fundamental mode signals are all performed by the same grating device, and it is not necessary to set an independent small mode for each fundamental mode signal.
  • the phase plate is used for phase conversion, the accuracy of the optical path is low, and the system is simple in structure and small in space.
  • the mode control system shown in the embodiment of the present invention only needs to increase the incident angle and the target mode to expand the channel, which is convenient. Expand the capacity of the optical interconnect.
  • FIG. 4A shows a structural diagram of a demultiplexing apparatus according to an embodiment of the present invention.
  • the demultiplexing device may be the demultiplexing device 120 in the system shown in FIG. 1.
  • the demultiplexing apparatus may include: a routing control unit 410, a controller 420, and a phase grating 430;
  • the controller 420 is electrically connected to the routing control unit 410 and the phase grating 430, respectively. Connected
  • the routing control unit 410 is configured to send, to the controller 420, diffraction information corresponding to each of the N channels of small mode signals, where the N channel mode signals are included in a multiplexed signal incident on the phase grating 430 a signal, the diffraction information including a current mode and a diffraction angle, N ⁇ 2, and N is an integer;
  • the controller 420 is configured to generate a phase hologram of the phase grating 430 according to the diffraction information corresponding to each of the N-channel mode signals, and transmit the phase hologram to the phase grating 430;
  • the phase grating 430 is configured to demodulate the multiplexed signal into N basic mode signals according to the phase hologram, wherein the N-way small-mode signals are in one-to-one correspondence with the N-way fundamental mode signals, and each way
  • the angle at which the fundamental mode signal is emitted from the exit end of the phase grating 430 is the diffraction angle of the corresponding small mode signal.
  • the controller 420 is configured to generate phase information of the small-mode grating corresponding to the N-channel mode signals according to the diffraction information corresponding to the N-channel mode signals when the phase hologram is generated. And generating a phase hologram of the phase grating 430 according to the corresponding small mode grating phase information of the N-way small-mode signals.
  • the mode information of the mode signal is the phase information of the phase grating when the mode signal is adjusted to the fundamental mode signal.
  • the controller 420 is configured to: when generating the phase information of the small mode grating corresponding to each of the N channels of small mode signals according to the diffraction information corresponding to each of the N channels of small mode signals, for each mode of the mode signal Generating a mode-less phase distribution function according to a current mode of the mode-less signal, generating a grating phase distribution function according to a diffraction angle of the mode-less signal, and generating a region according to the mode-less phase distribution function and the grating phase distribution function
  • the mode information of the modeless grating of the mode signal is described.
  • the mode-less phase distribution function is a phase distribution function of the current mode corresponding to the mode-less signal;
  • the grating phase distribution function is a phase grating that diffracts the vertically-injected mode-less signal to a corresponding diffraction angle, the phase grating Phase distribution function.
  • the controller 420 is configured to generate a phase hologram of the phase grating 430 according to the corresponding small mode grating phase information of the N-channel mode signals, according to the N-channel mode signals. Generating the phase information of the phase grating 430 by generating corresponding phase information of the mode grating, and performing holographic calculation on the composite phase information to obtain the phase hologram;
  • the composite phase information is expressed as:
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m (x, y) indicates the phase information of the mode-less grating corresponding to the (x, y) point of the m-th mode-less signal
  • r m ⁇ (x, y) is the grating corresponding to the m-th mode-less signal at the point (x, y)
  • a mode-less phase distribution function corresponding to the (x, y) point for the mth mode is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m (x, y) indicates the phase information of the mode-less grating corresponding to the (x, y) point of the m-th mode-less signal
  • the phase grating 430 re-multiplexes one multiplexed signal into N basic mode signals according to the phase grating generated by the controller 420 to update its phase information, and respectively emits the signals from different diffraction angles.
  • the phase grating 430 can also remodulate the N fundamental mode signals into N small mode signals, and N paths.
  • the mode-less signals are multiplexed into one multiplexed signal.
  • the controller 420 generates a phase hologram of the grating phase 430 according to the diffraction information corresponding to each of the N-channel mode signals, and should generate a phase grating with the corresponding information of the N-channel fundamental signals corresponding to the controller 310 in FIG. 3A.
  • the specific process of the phase hologram of 320 is similar, and the process may refer to the specific description in the corresponding embodiment of FIG. 3A, and details are not described herein again.
  • the step of generating a phase hologram according to the current mode and the diffraction angle corresponding to each mode of the small mode signal may be implemented by the controller 420 executing a software code stored in advance, or may be passed by each operation unit included in the controller 420. Logical operations are generated.
  • the controller 420 may include N control units and a phase hologram generating unit, and the N control units respectively correspond to the N-way small-mode signals.
  • Each control unit is composed of a small mode phase generating unit, a grating phase generating unit and a small mode grating phase generating unit. The working flow of each of the above units is similar to that of FIG. 3B and will not be described herein.
  • the device further includes: a spatial optical power meter 440; the spatial optical power meter 440 is disposed at an exit end of the phase grating 430, and the spatial optical power meter 440 and the controller 420 are electrically Connected
  • the spatial optical power meter 440 is configured to measure respective powers of the N fundamental mode signals emitted from an exit end of the phase grating 430;
  • the controller 420 is configured to perform a corresponding mode of the small mode grating according to the N-channel mode signals
  • the controller 420 is configured to perform a corresponding mode of the small mode grating according to the N-channel mode signals
  • the controller 420 is configured to calculate composite phase information of the phase grating 430 according to the following formula
  • a> 0, (x, y) are the coordinates of the incident end face of the phase grating
  • T 1 (x, y) is the first iteration calculation
  • the complex phase information of the phase grating 430 G m (x , y) represents the small-mode grating phase information corresponding to the (x, y) point of the m-th mode-less signal
  • r m ⁇ (x, y) is at the (x, y) point
  • the m-th mode of the mode-less signal corresponds to Grating phase distribution function
  • the controller 420 is further configured to calculate, when the phase grating 430 demodulates the multiplexed signal into N basic mode signals according to a phase hologram obtained by performing holographic calculation on T 1 (x, y)
  • the spatial optical power meter 440 measures the variance D 1 of the obtained power of the N fundamental mode signals;
  • the controller 420 is configured to use ⁇ 1 m as a final duty ratio coefficient corresponding to the m-th mode less-mode signal when the variance D 1 is less than or equal to a preset variance threshold;
  • the controller 420 is configured to perform a second iteration calculation when the variance D 1 is greater than a preset variance threshold.
  • the controller 420 is configured to calculate at the kth iteration, and the phase grating 430 compares the multiplexed signal according to a phase hologram obtained by performing holographic calculation on T k-1 (x, y)
  • the N paths are less
  • the duty cycle coefficient of each of the mode signals T k-1 (x, y) is the k-th iteration calculation, the phase grating 430 corresponds to the composite phase information of the (x, y) point; k ⁇ 2 and k is an integer;
  • the controller 420 is configured to calculate composite phase information of the phase grating according to the following formula
  • the controller 420 is further configured to calculate the space when the phase grating demodulates the multiplexed signal into N basic mode signals according to a phase hologram obtained by performing holographic calculation on T k (x, y)
  • the optical power meter 440 measures the variance D k of the obtained power of the N fundamental mode signals;
  • the controller 420 is configured to use ⁇ k m as a final duty ratio coefficient corresponding to the m-th mode less-mode signal when the variance D k is less than or equal to the variance threshold;
  • the controller 420 is configured to perform a k+1th iteration calculation when the variance D k is greater than the variance threshold.
  • the controller 420 adjusts the duty ratio coefficients corresponding to the respective small mode signals according to the measurement result of the spatial optical power meter 440, so as to implement the signals of the respective fundamental modes.
  • the controller 310 in the embodiment corresponding to FIG. 3A adjusts the duty ratio coefficients of the respective fundamental mode signals according to the measurement result of the spatial optical power meter 330, so as to implement power for each modeless mode signal.
  • the method of equalization is similar and will not be repeated here.
  • the relationship between integer periods is satisfied between the respective periods, that is, the distance between the diffraction positions of the respective fundamental mode signals when the phase grating is operated can be ensured.
  • the spacing between the channels is made uniform, so that the interference between the channels is more even, thereby improving the transmission performance.
  • the maintenance personnel can arbitrarily adjust the diffraction angles of the N fundamental modes by the routing control unit 410, thereby implementing routing control of the optical signals.
  • the demultiplexing device as the demultiplexing device 120 in the mode control system shown in FIG. 1 , it is assumed that the incident angle of the fundamental mode signal corresponding to the signal transmitting unit 1 corresponds to the signal receiving unit 1 in FIG. 1 .
  • the diffraction angle of the fundamental mode signal is the same, the incident angle of the fundamental mode signal corresponding to the signal transmitting unit 2 is the same as the diffraction angle of the fundamental mode signal corresponding to the signal receiving unit 2, and so on, and the fundamental mode signal corresponding to the signal transmitting unit i
  • the angle of incidence of the fundamental mode signal corresponding to the signal receiving unit i is the same.
  • the routing control unit in the demultiplexing device can be connected to an operable interface (not shown in FIG. 1). As shown in FIG. 4B, a maintenance control diagram adjusts the diffraction angle of each fundamental mode signal in an operable interface.
  • the base mode signal sent by the signal transmitting unit i is multiplexed and demultiplexed by the mode control system, it is received by the signal receiving unit i, and the working mode may be referred to as a direct connection mode.
  • the maintenance personnel adjusts the diffraction angle of each fundamental mode signal in the operable interface, so that the fundamental mode signal sent by the signal transmitting unit i is multiplexed and solved by the mode control system.
  • the signal receiving unit j After use, it is received by the signal receiving unit j, which may be referred to as an exchange mode; it is assumed that the multiplexed signal includes modes LP 11 , LP 12 , ..., LP 1N , a total of N modes of mode-less signals, and the phase grating
  • the N output ports correspond to the N signal receiving units, respectively.
  • the N output ports of the phase grating can be characterized by N diffraction angles, that is, the diffraction angles corresponding to the signal receiving unit 1, the signal receiving unit 2, ..., the signal receiving unit N, Characterized as ⁇ 1 , ⁇ 2 , ..., ⁇ N .
  • the maintenance personnel can select the output port of the desired output or the channel number to be transmitted according to the needs, and determine the diffraction angle according to the channel number.
  • the fundamental mode information corresponding to the LP 11 is expected to be output through the i-th output port, and the diffraction angle 1 in FIG. 4A is equal to ⁇ i .
  • the output port of the desired output according to the fundamental mode information corresponding to other modes can determine the diffraction angle 2 to the diffraction angle N, and so on.
  • the process of mode switching by the three-mode phase grating is taken as an example.
  • the three-way mode information in (a) is LP 11a , LP 01 and LP 11b , and (b) is exchanged.
  • the grating phases of LP 11a and LP 11b the two modes exchange positions, realizing the dynamic regulation of the mode.
  • the routing control unit sends the diffraction information corresponding to the N-channel mode signals to the controller, and the controller generates the phase grating according to the diffraction information corresponding to the N-channel mode signals.
  • Phase hologram the phase grating demodulates the multiplexed signal into N fundamental mode signals according to the phase hologram, and the N-way small-mode signals are in one-to-one correspondence with the N-way fundamental mode signals, and each of the fundamental mode signals is emitted from the exit end of the phase grating
  • the angle is the diffraction angle of the corresponding small-mode signal, and the demodulation and demultiplexing of the multi-path fundamental mode signal are all performed by the same grating device, the precision of the optical path is low, the system configuration is simple, and the occupied space is small;
  • the mode control system shown in the embodiment only needs to increase the diffraction angle and the current mode of the mode-less signal to expand the channel, thereby facilitating the expansion of the capacity of the optical interconnection.
  • the multiplexing device shown in FIG. 3A and the demultiplexing device shown in FIG. 4A of the present invention may constitute the mode control system shown in FIG. 1, and may also be used alone, for example, the complex shown in FIG. 3A.
  • the system is composed of a device and a conventional demultiplexing device, or the demultiplexing device shown in FIG. 4A and the conventional multiplexing device form a system, which is not limited in the embodiment of the present invention.
  • FIG. 5 shows a flowchart of a mode control method provided by an embodiment of the present invention.
  • the mode control method can be used in the multiplexing device shown in FIG. 3A, and is executed by a controller in the multiplexing device.
  • the mode control method may include:
  • Step 502 The controller receives the corresponding incident information of the N-channel fundamental signals, where the N-channel fundamental signals are fundamental signals that are simultaneously incident on the phase grating, and the incident information includes a target mode and an incident angle, N ⁇ 2, and N is Integer.
  • Step 504 The controller generates a phase hologram of the phase grating according to the corresponding incident information of the N-channel fundamental signals, and transmits the phase hologram to the phase grating, and the phase grating, according to the phase hologram, the N
  • the sub-module signal is modulated into a multiplexed signal, and the multiplexed signal includes N-channel modulo signals, and the N-channel modulo signals are in one-to-one correspondence with the N-channel modulo signals, and the mode of each of the modulo signals is a corresponding base.
  • the target mode of the mode signal is a corresponding base.
  • phase hologram of the phase grating is generated according to the corresponding incident information of the N-channel fundamental signals, including:
  • the controller generates phase information of the small-mode grating corresponding to the N-channel fundamental signals according to respective incident information of the N-channel fundamental signals, and generates phase of the phase grating according to the phase information of the corresponding small-mode gratings of the N-channel fundamental signals Hologram
  • the phase information of the small mode grating corresponding to the fundamental mode signal is phase information of the phase grating when the phase grating adjusts the fundamental mode signal to a corresponding small mode signal.
  • phase information of the small-mode grating corresponding to the N-channel fundamental signals is generated according to the corresponding incident information of the N-channel fundamental signals, including:
  • the controller For each fundamental mode signal, the controller generates a mode-less phase distribution function according to the target mode of the fundamental mode signal, generates a grating phase distribution function according to the incident angle of the fundamental mode signal, and according to the mode-less phase distribution function and the grating a phase distribution function generates phase information of the modeless grating of the fundamental mode signal;
  • the mode-less phase distribution function is a phase distribution function of a target mode corresponding to the fundamental mode signal;
  • the grating phase distribution function is a phase grating that diffracts a fundamental mode signal incident at a corresponding incident angle to The phase distribution function of the phase grating when it is perpendicular to the incident end face of the phase grating.
  • phase hologram of the phase grating is generated according to the phase information of the corresponding mode of the N-channel fundamental signals, including:
  • the controller generates composite phase information of the phase grating according to the phase information of the corresponding mode of the N-channel fundamental signals, and performs holographic calculation on the composite phase information to obtain the phase hologram;
  • the composite phase information is expressed as:
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m (x, y) represents the phase information of the mode-less grating corresponding to the (x, y) point of the m-th fundamental mode signal
  • r m ⁇ (x, y) is the grating phase distribution corresponding to the m-th fundamental mode signal at the point (x, y) function
  • It is the mode-less phase distribution function of the (m, y) point corresponding to the m-th fundamental mode signal.
  • the multiplexing device further includes: a spatial optical power meter; the method further includes:
  • the controller generates a phase hologram of the phase grating according to the corresponding small-mode grating phase information of the N-channel fundamental signals, and determines, according to the measurement result of the spatial optical power meter, the corresponding N-channel fundamental signals by iterative calculation
  • the duty cycle factor is used to achieve power equalization of the N-way mode-less signals.
  • determining, by iterative calculation, respective duty ratio coefficients of the N basic mode signals including:
  • the controller calculates composite phase information of the phase grating according to the following formula
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T 1 (x) is the composite phase information corresponding to the (x, y) point when the first iteration is calculated.
  • G m (x) represents the phase information of the small-mode grating corresponding to the (x, y) point of the m-th fundamental mode signal
  • r m ⁇ (x, y) is at the (x, y) point
  • the m-th fundamental mode signal corresponds to Grating phase distribution function, a mode-less phase distribution function corresponding to the (x, y) point of the m-th fundamental mode signal;
  • the controller calculates the N path obtained by the spatial optical power meter when the phase grating modulates the N fundamental mode signal into one multiplexed signal according to the phase hologram obtained by performing holographic calculation on T 1 (x, y) The variance of the power of the mode-less signal D 1 ;
  • the controller uses ⁇ 1 m as the final duty cycle coefficient corresponding to the m-th fundamental mode signal;
  • the controller When the variance D 1 is greater than a preset variance threshold, the controller performs a second iteration calculation.
  • determining, by iterative calculation, respective duty ratio coefficients of the N basic mode signals including:
  • the controller calculates at the kth iteration, and the phase grating modulates the N fundamental mode signals into one multiplexed signal according to a phase hologram obtained by holographic calculation of T k-1 (x, y), the controller
  • the respective powers of the path-less analog signals are normalized by the inverse of the total power of the multiplexed signals, and the duty ratio coefficients of the N-channel fundamental signals are obtained when the kth iteration is calculated;
  • T k-1 (x , y) is calculated for the k-1th iteration, the phase grating corresponds to the composite phase information of the (x, y) point;
  • k ⁇ 2 and k is an integer;
  • the controller calculates composite phase information of the phase grating according to the following formula
  • T k (x, y) is the k-th iteration calculation
  • the phase grating corresponds to the composite phase information of the (x, y) point
  • ⁇ k m is the k-th iteration calculation
  • the m-th fundamental mode signal corresponds to Duty cycle factor
  • the controller calculates the N path obtained by the spatial optical power meter when the phase grating modulates the N fundamental mode signal into a multiplexed signal according to the phase hologram obtained by performing holographic calculation on T k (x, y) D k variance less power mode signal;
  • the controller uses ⁇ k m as the final duty cycle coefficient corresponding to the m-th fundamental mode signal;
  • the controller When the variance D k is greater than the variance threshold, the controller performs a k+1th iteration calculation.
  • the grating periods corresponding to the N-channel mode signals are different, and the integer multiple relationship is satisfied with each other;
  • the controller may refer to the description in the corresponding embodiment in FIG. 3A, and details are not described herein again.
  • the mode control method shown in the embodiment of the present invention receives the incident information corresponding to each of the N fundamental modes by the controller, and generates a phase hologram of the phase grating according to the corresponding incident information of the N fundamental signals, and The phase hologram is transmitted to the phase grating, and the phase grating modulates the N fundamental mode signal into a multiplexed signal according to the phase hologram, and the multiplexed signal includes N small mode signals, and the N small mode signals correspond to the N fundamental mode signals one by one.
  • the mode of each mode of the small mode signal is the target mode of the corresponding fundamental mode signal, and the modulation and multiplexing of the multipath fundamental mode signals are all performed by the same grating device, and it is not necessary to set an independent small mode for each fundamental mode signal.
  • the phase plate is used for phase conversion, the accuracy of the optical path is low, and the system is simple in structure and small in space.
  • the mode control system shown in the embodiment of the present invention only needs to increase the incident angle and the target mode to expand the channel, which is convenient. Expand the capacity of the optical interconnect.
  • FIG. 6 shows a flowchart of a mode control method provided by an embodiment of the present invention.
  • the mode control method can be used in the demultiplexing device shown in FIG. 4A, and is executed by a controller in the demultiplexing device.
  • the mode control method may include:
  • Step 602 The controller receives the diffraction information corresponding to the N-channel small-mode signals sent by the routing control unit, where the N-channel small-mode signals are signals included in a multiplexed signal incident on the phase grating, and the diffraction information includes a current mode. And diffraction angle, N ⁇ 2, and N is an integer.
  • Step 604 The controller generates a phase hologram of the phase grating according to the diffraction information corresponding to each of the N-channel mode signals, and transmits the phase hologram to the phase grating, and the phase grating is configured according to the phase hologram Demodulating into a N-channel fundamental mode signal, the N-way small-mode signal is in one-to-one correspondence with the N-channel fundamental mode signal, and each of the fundamental mode signals is emitted from the exit end of the phase grating to be a corresponding mode-less signal. Diffraction angle.
  • the phase hologram of the phase grating is generated according to the diffraction information corresponding to each of the N-channel mode signals, including:
  • the controller generates phase information of the small-mode grating corresponding to the N-channel small-mode signals according to the diffraction information corresponding to the N-channel mode signals, and according to the corresponding-mode small-mode grating phase of the N-channel mode signals Bit information generates a phase hologram of the phase grating;
  • the mode information of the mode signal is the phase information of the phase grating when the phase mode grating adjusts the mode signal to the fundamental mode signal.
  • generating, according to the diffraction information corresponding to the N-channel mode signals, the phase information of the small-mode grating corresponding to the N-channel mode signals including:
  • the controller For each mode of the small mode signal, the controller generates a mode conversion phase distribution function according to the current mode of the mode signal, generates a grating phase distribution function according to the diffraction angle of the mode signal, and generates a phase according to the mode and the phase of the grating.
  • the mode-less grating phase information of the mode-less signal
  • the mode-less phase distribution function is a phase distribution function of a current mode corresponding to the mode-less signal;
  • the grating phase distribution function is a phase grating that diffracts a vertically-injected small-mode signal to a corresponding diffraction angle, the phase grating Phase distribution function.
  • phase hologram of the phase grating is generated according to the phase information of the small-mode grating corresponding to the N-channel mode signals, including:
  • the controller generates composite phase information of the phase grating according to the corresponding small-mode grating phase information of the N-channel mode signals, and performs holographic calculation on the composite phase information to obtain the phase hologram;
  • the composite phase information is expressed as:
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m (x, y) indicates the phase information of the mode-less grating corresponding to the (x, y) point of the m-th mode-less signal
  • r m ⁇ (x, y) is the grating corresponding to the m-th mode-less signal at the point (x, y)
  • a mode-less phase distribution function corresponding to the (x, y) point for the mth mode is the coordinate on the incident end face of the phase grating
  • T(x, y) is the composite phase information of the phase grating corresponding to the (x, y) point
  • G m (x, y) indicates the phase information of the mode-less grating corresponding to the (x, y) point of the m-th mode-less signal
  • the demultiplexing device further includes: a spatial optical power meter; the method further includes:
  • the controller generates a phase hologram of the phase grating according to the corresponding small-mode grating phase information of the N-channel mode signals, and determines, according to the measurement result of the spatial optical power meter, the N-channel small-mode signals by an iterative calculation. Corresponding duty cycle coefficients are used to achieve power equalization of the N fundamental mode signals.
  • determining, by iterative calculation, respective duty ratio coefficients of the N-channel mode signals including:
  • the controller calculates composite phase information of the phase grating according to the following formula
  • (x, y) is the coordinate on the incident end face of the phase grating
  • T 1 (x, y) is the composite of the (x, y) point when the first iteration is calculated.
  • the phase information, G m (x, y) represents the mode information of the mode-less grating corresponding to the (x, y) point of the m-th mode-less signal
  • r m ⁇ (x, y) is at the (x, y) point
  • the m-path less mode signal corresponds to the grating phase distribution function of the (x, y) point, a mode-less phase distribution function corresponding to the (x, y) point of the m-th mode-less signal;
  • the controller calculates the N-channel base obtained by the spatial optical power meter when the phase grating demodulates the multiplexed signal into an N-way fundamental mode signal according to a phase hologram obtained by performing holographic calculation on T 1 (x, y) The variance of the power of the mode signal D 1 ;
  • the controller uses ⁇ 1 m as the final duty cycle coefficient corresponding to the m-th mode less-mode signal;
  • the controller When the variance D 1 is greater than a preset variance threshold, the controller performs a second iteration calculation.
  • determining, by iterative calculation, respective duty ratio coefficients of the N-channel mode signals including:
  • the controller bases the N base
  • the respective powers of the mode signals are divided by the inverse ratio of the total power of the multiplexed signals, and the duty ratio coefficients of the N-way small-mode signals are obtained when the k-th iteration is calculated;
  • T k-1 (x, y) for the k-1th iteration, the phase grating corresponds to the composite phase information of the (x, y) point;
  • k ⁇ 2 and k is an integer;
  • the controller calculates composite phase information of the phase grating according to the following formula
  • phase grating corresponds to the composite phase information of the (x, y) point, and ⁇ k m is the m- th less mode signal when the k-th iteration is calculated.
  • the controller calculates the N-base obtained by the spatial optical power meter when the phase grating demodulates the multiplexed signal into an N-way fundamental mode signal according to the phase hologram obtained by performing holographic calculation on T k (x, y).
  • the variance of the power of the mode signal D k D k ;
  • the controller uses ⁇ k m as the final duty cycle coefficient corresponding to the m-th mode less-mode signal;
  • the controller When the variance D k is greater than the variance threshold, the controller performs a k+1th iteration calculation.
  • the grating periods corresponding to the N-channel mode signals are different, and the integer multiple relationship is satisfied with each other;
  • the controller may refer to the description in the corresponding embodiment in FIG. 4A, and details are not described herein again.
  • the controller receives the diffraction information corresponding to the N-channel small-mode signals sent by the routing control unit, and generates the phase grating according to the diffraction information corresponding to the N-channel mode signals.
  • the phase hologram, the phase grating demodulates the multiplexed signal into N fundamental mode signals according to the phase hologram, and the N-way small-mode signals are in one-to-one correspondence with the N-way fundamental mode signals, and each of the fundamental mode signals is emitted from the exit end of the phase grating.
  • the angle is the diffraction angle of the corresponding small mode signal, and the demodulation and demultiplexing of the multipath fundamental mode signal are all performed by the same grating device, the precision of the optical path is low, and the system configuration is simple and the occupied space is small; further, the implementation of the invention
  • the mode control system shown in the example only needs to increase the diffraction angle and the current mode of the mode-less signal to expand the channel, which is convenient for expanding the capacity of the optical interconnection.

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Abstract

本发明实施例提供了一种复用装置、解复用装置、模式控制方法及系统，涉及光通信领域，所述复用装置包括：控制器和相位光栅；控制器和相位光栅电性相连；控制器用于接收N路基模信号各自对应的入射信息，根据N路基模信号各自对应的入射信息生成相位光栅的相位全息图，并将相位全息图传输给相位光栅；相位光栅用于根据相位全息图将N路基模信号调制为一路复用信号。本发明通过控制器接收N路基模信号各自对应的入射信息，根据N路基模信号各自对应的入射信息生成相位光栅的相位全息图，不需要为每一个基模信号设置一个独立的少模相位片来进行相位转换，对光路的精度要求低，且系统构成简单，占用空间小，便于扩展光互联的容量。

Description

复用装置、解复用装置、模式控制方法及系统 技术领域
本发明涉及光通信领域，特别涉及一种复用装置、解复用装置、模式控制方法及系统。
背景技术
随着信息技术领域的不断发展，极短-短距离互联对传输容量和传输密度的需求已经成为亟待解决的问题，而少模模式复用缓解该问题的一个成熟方案。
少模模式复用是指将多路基模信号分别调制在不同的少模模式上并合为一路复用信号进行传输的技术。调制到少模模式上的信号可称为“少模信号”。在现有技术中，N路基模信号中的每一路信号各自对应一个少模相位片，每一路基模信号分别通过对应的少模相位片后调制为对应模式的少模信号，N路少模信号再通过同一个分束器合为一路复用信号，从而完成多路光信号的少模模式复用。
在实现本发明的过程中，发明人发现现有技术至少存在以下问题：
现有技术中，需要为每一路基模信号分别设置一个少模相位片，随着复用模式的增加，需要的少模相位片也会相应增加，当复用的模式较多时，系统构成复杂，对光路的精度要求高，占用空间较大。
发明内容
为了解决现有技术中需要为每一路基模信号分别设置一个少模相位片，导致当复用的模式较多时，系统构成复杂，对光路的精度要求高，占用空间较大的问题，本发明实施例提供了一种复用装置、解复用装置、模式控制方法及系统。所述技术方案如下：
第一方面，提供一种复用装置，所述复用装置包括：控制器和相位光栅；
所述控制器和所述相位光栅电性相连；
所述控制器，用于接收N路基模信号各自对应的入射信息，所述N路基模信号为同时入射至所述相位光栅的基模信号，所述入射信息包括目标模式和入射角度，N≥2，且N为整数；
所述控制器，用于根据所述N路基模信号各自对应的入射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅；
所述相位光栅，用于根据所述相位全息图将所述N路基模信号调制为一路复用信号，所述复用信号中包含N路少模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式。
在第一方面的第一种可能实现方式中，
所述控制器，用于在生成所述相位全息图时，根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息，并根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
对于所述N路基模信号中的每一路基模信号，所述基模信号对应的少模光栅相位信息是所述相位光栅将所述基模信号调整为对应的少模信号时，所述相位光栅的相位信息。
结合第一方面的第一种可能实现方式，在第一方面的第二种可能实现方式中，所述控制器，用于在根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息时，对于每一路基模信号，根据所述基模信号的目标模式生成少模相位分布函数，根据所述基模信号的入射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述基模信号的少模光栅相位信息；
其中，所述少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将以对应的入射角度射入的基模信号衍射到与所述相位光栅的入射端面垂直的方向时，所述相位光栅的相位分布函数。
结合第一方面的第一或者第二种可能实现方式，在第一方面的第三种可能实现方式中，所述控制器，用于在根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信 息进行全息计算，获得所述相位全息图；
所述复合相位信息表示为：
Figure PCTCN2015082484-appb-000001
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000002
为第m路基模信号对应于(x，y)点的少模相位分布函数。
结合第一方面的第一或者第二种可能实现方式，在第一方面的第四种可能实现方式中，所述装置还包括：空间光功率计；所述空间光功率计设置于所述相位光栅的出射端，且所述空间光功率计与所述控制器电性相连；
所述空间光功率计，用于测量从所述相位光栅的出射端射出的复用信号中，所述各个少模信号的功率；
所述控制器，用于在根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，以实现对所述N路少模信号的功率均衡。
结合第一方面的第四种可能实现方式，在第一方面的第五种可能实现方式中，所述控制器，用于在第1次迭代计算时，确定所述N路基模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000003
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅的对应于(x，y)点复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x， y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000004
为第m路基模信号对应于(x，y)点的少模相位分布函数；
所述控制器，还用于在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差D1；
所述控制器，用于当所述方差D1小于等于预设的方差阈值时，将α1 m作为第m路基模信号对应的最终的占空比系数；
所述控制器，用于当所述方差D1大于预设的方差阈值时，进行第2次迭代计算。
结合第一方面的第五种可能实现方式，在第一方面的第六种可能实现方式中，所述控制器，用于在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，对所述N路少模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路基模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000005
其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路基模信号对应的占空比系数；
所述控制器，还用于在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差Dk；
所述控制器，用于当所述方差Dk小于等于所述方差阈值时，将αk m作为第m路基模信号对应的最终的占空比系数；
所述控制器，用于当所述方差Dk大于所述方差阈值时，进行第k+1次迭代计算。
结合第一方面或者第一方面第一至六种可能实现方式中的任意一种，在第一方面的第七种可能实现方式中，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的基模信号的入射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
第二方面，提供一种解复用装置，所述解复用装置包括：路由控制单元、控制器以及相位光栅；
所述控制器分别与所述路由控制单元以及所述相位光栅电性相连；
所述路由控制单元，用于向所述控制器发送N路少模信号对应的衍射信息，所述N路少模信号为入射至所述相位光栅的一路复用信号中包含的信号，所述衍射信息包括当前模式和衍射角度，N≥2，且N为整数；
所述控制器，用于根据所述N路少模信号各自对应的衍射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅；
所述相位光栅，用于根据所述相位全息图将所述复用信号解调为N路基模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路所述基模信号从所述相位光栅的出射端射出的角度为对应的少模信号的衍射角度。
在第二方面的第一种可能实现方式中，所述控制器，用于在生成所述相位全息图时，根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息，并根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
对于所述N路少模信号中的每一路少模信号，所述少模信号对应的少模光栅相位信息是所述相位光栅将所述少模信号调整为基模信号时，所述相位光栅的相位信息。
结合第二方面的第一种可能实现方式，在第二方面的第二种可能实现方式中，所述控制器，用于在根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息时，对于每一路少模信号，根据所述少模信号的当前模式生成少模相位分布函数，根据所述少模信号的衍射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述少模信号的少模光栅相位信息；
其中，所述少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将垂直射入的少模信号衍射至对应的衍射角度时，所述相位光栅的相位分布函数。
结合第二方面的第一或者第二种可能实现方式，在第二方面的第三种可能实现方式中，所述控制器，用于在根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
所述复合相位信息表示为：
Figure PCTCN2015082484-appb-000006
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000007
为第m路少模信号对应于(x，y)点的少模相位分布函数。
结合第二方面的第一或者第二种可能实现方式，在第二方面的第四种可能实现方式中，所述装置还包括：空间光功率计；所述空间光功率计设置于所述相位光栅的出射端，且所述空间光功率计与所述控制器电性相连；
所述空间光功率计，用于测量从所述相位光栅的出射端射出的所述N个基模信号各自的功率；
所述控制器，用于在根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，以实现对所述N路基模信号的功率均衡。
结合第二方面的第四种可能实现方式，在第二方面的第五种可能实现方式中，所述控制器，用于在第1次迭代计算时，确定所述N路少模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000008
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000009
为第m路少模信号对应于(x，y)点的少模相位分布函数；
所述控制器，还用于在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差D1；
所述控制器，用于当所述方差D1小于等于预设的方差阈值时，将α1 m作为第m路少模信号对应的最终的占空比系数；
所述控制器，用于当所述方差D1大于预设的方差阈值时，进行第2次迭代计算。
结合第二方面的第五种可能实现方式，在第一方面的第六种可能实现方式中，所述控制器，用于在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，对所述N路基模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路少模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000010
其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路少模信号对应的占空比系数；
所述控制器，还用于在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差Dk；
所述控制器，用于当所述方差Dk小于等于所述方差阈值时，将αk m作为第m路少模信号对应的最终的占空比系数；
所述控制器，用于当所述方差Dk大于所述方差阈值时，进行第k+1次迭代计算。
结合第二方面或者第二方面第一至六种可能实现方式中的任意一种，在第二方面的第七种可能实现方式中，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的衍射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
第三方面，提供一种模式控制方法，用于复用装置中，所述复用装置包括：控制器和相位光栅，所述方法包括：
所述控制器接收N路基模信号各自对应的入射信息，所述N路基模信号为同时入射至所述相位光栅的基模信号，所述入射信息包括目标模式和入射角度，N≥2，且N为整数；
所述控制器根据所述N路基模信号各自对应的入射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅，由所述相位光栅，根据所述相位全息图将所述N路基模信号调制为一路复用信号，所述复用信号中包含N路少模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式。
在第三方面的第一种可能实现方式中，所述根据所述N路基模信号各自对应的入射信息生成所述相位光栅的相位全息图，包括：
所述控制器根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息，并根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
对于所述N路基模信号中的每一路基模信号，所述基模信号对应的少模光栅相位信息是所述相位光栅将所述基模信号调整为对应的少模信号时，所述相 位光栅的相位信息。
结合第三方面的第一种可能实现方式，在第三方面的第二种可能实现方式中，所述根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息，包括：
对于每一路基模信号，所述控制器根据所述基模信号的目标模式生成少模相位分布函数，根据所述基模信号的入射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述基模信号的少模光栅相位信息；
其中，所述少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将以对应的入射角度射入的基模信号衍射到与所述相位光栅的入射端面垂直的方向时，所述相位光栅的相位分布函数。
结合第三方面的第一或者第二种可能实现方式，在第三方面的第三种可能实现方式中，所述根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图，包括：
所述控制器根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
所述复合相位信息表示为：
Figure PCTCN2015082484-appb-000011
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000012
为第m路基模信号对应于(x，y)点的少模相位分布函数。
结合第三方面的第一或者第二种可能实现方式，在第三方面的第四种可能实现方式中，所述复用装置还包括：空间光功率计；所述方法还包括：
所述控制器在根据所述N路基模信号各自对应的少模光栅相位信息生成 所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，以实现对所述N路少模信号的功率均衡。
结合第三方面的第四种可能实现方式，在第三方面的第五种可能实现方式中，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，包括：
在第1次迭代计算时，所述控制器确定所述N路基模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
所述控制器根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000013
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x)为第1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，Gm(x)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000014
为第m路基模信号对应于(x，y)点的少模相位分布函数；
所述控制器在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差D1；
当所述方差D1小于等于预设的方差阈值时，所述控制器将α1 m作为第m路基模信号对应的最终的占空比系数；
当所述方差D1大于预设的方差阈值时，所述控制器进行第2次迭代计算。
结合第三方面的第五种可能实现方式，在第三方面的第六种可能实现方式中，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，包括：
在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，所述控制器对所述N路少模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路基模信号各自的占空比系数；Tk-1(x，y) 为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
所述控制器根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000015
其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路基模信号对应的占空比系数；
所述控制器在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差Dk；
当所述方差Dk小于等于所述方差阈值时，所述控制器将αk m作为第m路基模信号对应的最终的占空比系数；
当所述方差Dk大于所述方差阈值时，所述控制器进行第k+1次迭代计算。
结合第三方面或者第三方面第一至六种可能实现方式中的任意一种，在第三方面的第七种可能实现方式中，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的基模信号的入射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
第四方面，提供一种模式控制方法，用于解复用装置中，所述解复用装置包括：路由控制单元、控制器和相位光栅，所述方法包括：
所述控制器接收所述路由控制单元发送的N路少模信号对应的衍射信息，所述N路少模信号为入射至所述相位光栅的一路复用信号中包含的信号，所述衍射信息包括当前模式和衍射角度，N≥2，且N为整数；
所述控制器根据所述N路少模信号各自对应的衍射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅，由所述相位光栅根据所述相位全息图将所述复用信号解调为N路基模信号，所述N路少模信 号与所述N路基模信号一一对应，且每一路所述基模信号从所述相位光栅的出射端射出的角度为对应的少模信号的衍射角度。
在第四方面的第一种可能实现方式中，所述根据所述N路少模信号各自对应的衍射信息生成所述相位光栅的相位全息图，包括：
所述控制器根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息，并根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
对于所述N路少模信号中的每一路少模信号，所述少模信号对应的少模光栅相位信息是所述相位光栅将所述少模信号调整为基模信号时，所述相位光栅的相位信息。
结合第四方面的第一种可能实现方式，在第四方面的第二种可能实现方式中，所述根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息，包括：
对于每一路少模信号，所述控制器根据所述少模信号的当前模式生成少模相位分布函数，根据所述少模信号的衍射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述少模信号的少模光栅相位信息；
其中，所述少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将垂直射入的少模信号衍射至对应的衍射角度时，所述相位光栅的相位分布函数。
结合第四方面的第一或者第二种可能实现方式，在第四方面的第三种可能实现方式中，所述根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图，包括：
所述控制器根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
所述复合相位信息表示为：
Figure PCTCN2015082484-appb-000016
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000017
为第m路少模信号对应于(x，y)点的少模相位分布函数。
结合第四方面的第一或者第二种可能实现方式，在第四方面的第四种可能实现方式中，所述解复用装置还包括：空间光功率计；所述方法还包括：
所述控制器在根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，以实现对所述N路基模信号的功率均衡。
结合第四方面的第四种可能实现方式，在第四方面的第五种可能实现方式中，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，包括：
在第1次迭代计算时，所述控制器确定所述N路少模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
所述控制器根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000018
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000019
为第m路少模信号对应于(x，y)点的少模相位分布函数；
所述控制器在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差D1；
当所述方差D1小于等于预设的方差阈值时，所述控制器将α1 m作为第m路少模信号对应的最终的占空比系数；
当所述方差D1大于预设的方差阈值时，所述控制器进行第2次迭代计算。
结合第四方面的第五种可能实现方式，在第四方面的第六种可能实现方式中，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，包括：
在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述复用信号调制为N路基模信号时，所述控制器对所述N路基模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路少模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
所述控制器根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000020
其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路少模信号对应的占空比系数；
所述控制器在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差Dk；
当所述方差Dk小于等于所述方差阈值时，所述控制器将αk m作为第m路少模信号对应的最终的占空比系数；
当所述方差Dk大于所述方差阈值时，所述控制器进行第k+1次迭代计算。
结合第四方面或者第四方面第一至六种可能实现方式中的任意一种，在第四方面的第七种可能实现方式中，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的衍射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
第五方面，提供一种模式控制系统，所述系统包括：
如上述第一方面或者第一方面的任意一种可能实现方式所示的复用装置，以及，如上述第二面或者第二方面的任意一种可能实现方式所示的解复用装置。
本发明实施例提供的技术方案的有益效果是：
通过控制器接收N路基模信号各自对应的入射信息，根据N路基模信号各自对应的入射信息生成相位光栅的相位全息图，并将相位全息图传输给相位光栅，相位光栅根据相位全息图将N路基模信号调制为一路复用信号，复用信号中包含N路少模信号，N路少模信号与N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式，多路基模信号的调制和复用都由同一个光栅器件完成，不需要为每一个基模信号设置一个独立的少模相位片来进行相位转换，对光路的精度要求低，且系统构成简单，占用空间小；此外，本发明实施例所示的模式控制系统，只需要增加入射角度和目标模式即可以扩展信道，便于扩展光互联的容量。
附图说明
为了更清楚地说明本发明实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是本发明一个实施例提供的模式控制系统的结构图；
图2A是本发明一个实施例提供的少模信号产生及调制装置的结构图；
图2B是本发明一个实施例提供的一种光信号入射示意图；
图2C是本发明一个实施例提供的一种相位光栅的相位分布图；
图2D是本发明一个实施例提供的一种相位全息图；
图2E是本发明一个实施例提供的控制器的内部单元结构图；
图3A是本发明一个实施例提供的复用装置的结构图；
图3B是本发明一个实施例提供的控制器的结构图；
图3C是本发明一个实施例提供的五模相位光栅的实验测量与模拟效果对比图；
图3D是本发明一个实施例提供的可以完成LP21，LP11a，LP01，LP11b及LP31 五个模式信号的调制和复用的相位光栅的相位全息图；
图4A是本发明一个实施例提供的解复用装置的结构图；
图4B是本发明一个实施例提供的一种路由控制示意图；
图4C是本发明一个实施例提供的另一种路由控制示意图；
图4D是本发明一个实施例提供的模式交换模拟图；
图5是本发明一个实施例提供的模式控制方法的流程图；
图6是本发明一个实施例提供的模式控制方法的流程图。
具体实施方式
为使本发明的目的、技术方案和优点更加清楚，下面将结合附图对本发明实施方式作进一步地详细描述。
请参考图1，其示出了本发明一个实施例提供的模式控制系统100的结构图。如图1所示，该模式控制系统100可以包括：复用装置110、解复用装置120、N个信号发射单元130以及N个信号接收单元140；
复用装置110中包含第一控制器112和第一相位光栅114，且第一控制器112和第一相位光栅114电性相连；解复用装置120中包含路由控制单元122、第二控制器124和第二相位光栅126，且第二控制器124和路由控制单元122以及第二相位光栅126分别电性相连。
N个信号发射单元130各自通过不同的入射角度向第一相位光栅发射一路基模信号，第一相位光栅114将N个信号发射单元130分别发射的基模信号调制复用为一路复用信号，并从出射端射出，该复用信号通过空间传输后入射至第二相位光栅126；第二相位光栅126将该复用信号解调为N路基模信号，并将解调出的N路基模信号按照不同的衍射角度射出，并分别由N个信号接收单元140接收。
其中，入射角度是指基模信号的入射方向与第一相位光栅的入射端面的垂直线之间的夹角，同理，衍射角度是指基模信号的出射方向与第二相位光栅的出射端面的垂直线之间的夹角。
模式可以理解成光波在空间上的场的分布形式。其表征量的是强度，相位，相位变化的频率等。因此不同的模式，可以理解上在空间上不同的场分布形式。由于具有正交性的多个模式的少模信号之间干扰较小，因此可以通过同一物理 信道传输，从而增加物理信道的传输容量。
本发明实施例所示的模式控制系统中，光信号的发送端只需要一个相位光栅，即可以实现将多个基模信号分别调制为不同的少模信号并合成一路复用信号，光信号的接收端也只需要一个相位光栅即可以将一路复用信号解复用成多路基模信号，并分别从不同的衍射角度射出，不需要为每一个基模信号设置一个独立的少模相位片来进行相位转换，对光路的精度要求低，且系统构成简单，占用空间小；此外，本发明实施例所示的模式控制系统，只需要增加入射角度和目标模式即可以扩展信道，便于扩展光互联的容量。
请参考图2A，其示出了本发明实施例提供的一种少模信号产生及调制装置的结构图。该少模信号产生及调制装置可以用于将一路基模信号调制为某一目标模式的少模信号。
如图2A所示，该少模信号产生及调制装置包括控制器210以及相位光栅220。输入信号为一路基模信号，以及该基模信号的入射角度及其期望调整到的目标模式。其中，基模信号直接入射至相位光栅，其对应的入射角度及目标模式输入至控制器。输出信号为一路调制到目标模式上的少模信号。
假设基模信号以入射角θ入射至相位光栅，其预期调制到的目标模式为LPim模，则控制器根据角度和目标模式LPim产生相位全息图，并将相位全息图发送至相位光栅，控制相位光栅进行相位信息的调整。当该基模信号入射至调整后的相位光栅后，即可输出调制到LPim模式上的少模信号。
其中，少模信号产生及调制装置对基模信号进行调制的步骤可以如下：
步骤1、控制器根据输入的基模信号需要调制到的目标模式确定少模相位分布函数。
其中，基模信号对应少模相位分布函数是该基模信号对应的目标模式的相位信息。在相位光栅的入射端面上建立平面直角坐标系，一个少模信号的模式电场通常可以表达式为
Figure PCTCN2015082484-appb-000021
EA为一般高斯或者其他电场表达式，(x，y)表示与少模信号的传输方向垂直的横截面上的坐标，其中，
Figure PCTCN2015082484-appb-000022
Figure PCTCN2015082484-appb-000023
即为少模信号对应于(x，y)点的少模相位分布函数，不同的少模信号对应的
Figure PCTCN2015082484-appb-000024
不同，本发明实施例可以根据基模信号的目标模式确定
Figure PCTCN2015082484-appb-000025
Figure PCTCN2015082484-appb-000026
步骤2、控制器根据输入的入射角度确定光栅相位分布函数。
基模信号的光栅相位分布函数是指一个相位光栅将以对应的入射角度射入的基模信号衍射到与相位光栅的入射端面垂直的方向时，该相位光栅的相位分布函数。在本发明实施例中，相位光栅可以只在上述步骤1所述平面直角坐标系中的x轴和y轴之间的某个夹角上进行相位转换；本发明实施例中，(x，y)坐标点对应的光栅相位表达为：
Figure PCTCN2015082484-appb-000027
其中，a为预设值，且a＞0，r＝2π/d，d为该相位光栅的光栅周期，r为相位变化的频率，代表单位坐标上相位的变化量，也称之为相位周期，i为虚数符号。在本发明中，d是由基模信号入射角θ来唯一确定。光栅周期d与入射角度θ之间的关系满足：sinθ＝λ/(2*d)，其中，λ为入射的基模信号的波长。
在实际应用中，可以根据输入的基模信号所在的入射角θ在线获取周期信息，也可以提前根据光栅的特点选择合适的周期信息和其对应的入射角形成表格，并将表格存在控制器中，通过识别基模信号的入射角θ来查表获取光栅周期。
请参考图2B所示的光信号入射示意图，其中，一束基模信号21以入射角θ入射至相位光栅的入射端面22，并以垂直于入射端面22的角度射出。设该相位光栅有效的尺寸是2cm*2cm，全部光栅分为1025*1025份，刻蚀精度为2/1025(刻蚀精度主要由工艺决定，代表所能表征的相位变化的最小量)，已知一个光栅周期内有12个最小单位，即一个周期的光栅分成了12份，因此，只有d÷12(um)≥2÷1025(nm)，即d≥23.4(um)时，才能使相位光栅较好的工作。令r＝2π÷d(mm)，即当r≤268时，可以实现相位光栅的正常工作。本发明实施例以r＝260(理论上r是越大越好)为例进行说明，如表1所示，基模信号21的入射角度θ与对应的光栅周期之间的对应关系可以如下：
θ 1.83° 3.67° 5.50° 7.34°
d 24.17um 12.085um 8.086um 6.066um
表1
其中，当入射角度为1.83°时，周期d＝2π÷r(mm)＝2π÷260(mm)＝24.17(um)。此时，设该相位光栅为闪耀光栅，且闪耀光栅仅在入射端面中的x轴方向上对入射的基模信号进行闪耀，则对以1.83°入射的基模信号进行闪耀时，该相位光栅的相位分布图可以如图2C所示。
同理，当d＝2π÷(2*r)(mm)＝2π÷520(mm)＝12.085(um)时，对应的θ为3.67°。
进一步的，在空间光通信中，入射角度θ可以作为不同传输信道(或不同输入口)的表征，每一个入射角度对应一个信号，因此也可以直接存储信道号与周期信息的对应关系。
步骤3、控制器根据产生的少模相位分布函数和光栅相位分布函数产生相位光栅的相位全息图。
根据步骤1和步骤2产生的少模相位分布函数
Figure PCTCN2015082484-appb-000028
和光栅相位分布函数rΦ(x，y)得到该相位光栅的相位信息为
Figure PCTCN2015082484-appb-000029
进一步，该相位光栅的函数表达式可记为
Figure PCTCN2015082484-appb-000030
T(x，y)即为相位光栅在(x，y)点处的相位信息，根据相位光栅的相位信息，通过全息计算即可得到该相位光栅的相位全息图。该相位全息图里既包含少模的信息，又包含闪耀光栅的信息。
步骤4、控制器将产生的相位全息图更新至相位光栅，当基模信号入射至该相位光栅时，即可将其调制为指定模式的少模信号，同时使该少模信号的衍射方向与该相位光栅的入射端面垂直。
其中，以LP11模的少模信号为例来说明其对应的相位光栅的相位全息图的产生过程。
在光纤波导中，满足麦克斯韦方程组的混合模式HEl-1m和EHl+1m的组合为线性极化模，记做LPlm模，其中l为l阶贝塞尔函数，m为l阶贝塞尔函数的第l个根。LP11是光纤波导中麦克斯韦方程组解中的第一类贝塞尔函数对应的1阶的第一个根，根据其本身模场的特点规定：
模场关于y轴对称的，称为LP11a模式；模场关于x轴对称的，称为LP11b模式，其相位上的表达式可以表式为：
Figure PCTCN2015082484-appb-000031
在本发明实施例中，相位光栅的相位变化频率为r，其中，(x，y)是相位光栅的入射端面上的坐标，根据光栅的刻蚀精度，取各个不同的坐标点(x，y) 处的相位值
Figure PCTCN2015082484-appb-000032
即可得到该相位光栅将基模信号调制为LP11a模式信号，并将该LP11a模式信号衍射到与入射端面垂直的方向时的相位全息图。以相位光栅有效的尺寸是2cm*2cm，全部光栅分为1025*1025份，且r取260为例，通过全息计算后得到产生的相位全息图可以如图2D所示。
需要说明的是，上述根据入射角度和目标模式生成相位全息图并输入相位光栅的步骤可以由控制器通过执行预先存储的程序代码来执行，也可以由控制器中包含的运算单元通过逻辑运算来执行。
当由控制器210中包含的运算单元通过逻辑运算来执行上述步骤时，该控制器210可以包括少模相位产生单元211、光栅相位产生单元212及相位全息图产生单元213，少模相位产生单元211接收输入的目标模式，并根据目标模式确定少模相位，光栅相位产生单元212接收输入的入射角度，并根据入射角度确定光栅相位，相位全息图产生单元213根据少模相位和光栅相位产生相位光栅的相位全息图，该控制器210的内部单元结构图可以如图2E所示。
对图2A所示的装置进行扩展，即可以获得图1所示系统中的复用装置。请参考图3A，其示出了本发明一个实施例提供的复用装置的结构图。其中，该复用装置可以是图1所示系统中的复用装置110。如图3A所示，该复用装置可以包括：控制器310和相位光栅320；
所述控制器310和所述相位光栅320电性相连；
所述控制器310，用于接收N路基模信号各自对应的入射信息，所述N路基模信号为同时入射至所述相位光栅320的基模信号，所述入射信息包括目标模式和入射角度，N≥2，且N为整数；
所述控制器310，用于根据所述N路基模信号各自对应的入射信息生成所述相位光栅320的相位全息图，并将所述相位全息图传输给所述相位光栅320；
所述相位光栅320，用于根据所述相位全息图将所述N路基模信号调制为一路复用信号，所述复用信号中包含N路少模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式。
其中，该相位光栅可以是闪耀光栅，该光栅可以直接将控制器通过数学算法产生的相位全息图导进空间光调制器(英文全称：Spatial Light Modulator， 缩写：SLM)，成为可调控光栅器件。
在本发明实施例中，相位光栅根据控制器发送的接收到的相位全息图对自身的相位进行更新，后续N个信号发射单元通过不同的入射角度，分别将一路基模信号发送至相位光栅后，相位光栅按照更新后的相位，将N路基模信号分别调制为对应模式的少模信号，并将调制生成的N路少模信号合成为一路复用信号，多路基模信号的调制和复用都由同一个光栅器件完成。
可选的，所述控制器310，用于在生成所述相位全息图时，根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息，并根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图。
对于该N路基模信号中的每一路基模信号，该基模信号对应的少模光栅相位信息是相位光栅将该述基模信号调整为对应的少模信号时，该相位光栅的相位信息。
所述控制器310，用于在根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息时，对于每一路基模信号，根据所述基模信号的目标模式生成少模相位分布函数，根据所述基模信号的入射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述基模信号的少模光栅相位信息。
其中，该少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；光栅相位分布函数是相位光栅将以对应的入射角度射入的基模信号衍射到与该相位光栅的入射端面垂直的方向时，该相位光栅的相位分布函数。
可选的，所述控制器310，用于在根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
所述复合相位信息表示为：
Figure PCTCN2015082484-appb-000033
其中，a＞0，(x，y)是该相位光栅的入射端面上的坐标，T(x，y)为所 述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000034
为第m路基模信号对应于(x，y)点的少模相位分布函数。
复用装置是将N路以不同角度入射的基模信号调制到N个不同的少模信号上，并复用成一路信号后输出的光信号处理装置。其中，每一个入射角度相当于一个信道，N个信道与N个入射角度对应，将N路基模信号对应的入射角度1、入射角度2、……、入射角度N和目标模式1、目标模式2、……、目标模式N输入至控制器后，控制器根据这些信息生成闪耀光栅的相位全息图并输入至闪耀光栅，更新闪耀光栅的相位信息。N路基模信号通过更新后的闪耀光栅时，闪耀光栅将N路基模信号调制到N个不同的少模信号上，并复用为一路信号后输出，这就完成了N个不同模式的调制和复用。由于少模信号的不同模式之间存在正交性，因此复用后的信号不会相互干扰，可以在同一个信道上传输，从而增加了信道的传输容量。
其中，控制器生成相位全息图的步骤可以如下所示：
步骤1，控制器利用输入的每一个基模信号的目标模式和入射角度分别产生各自对应的少模相位分布函数和光栅相位分布函数，并产生其对应的少模光栅相位信息。
假设基模信号1到基模信号N的入射角度分别为θ1、θ2、……、θN，根据入射角度唯一确定其对应的周期信息分别为d1、d2、……、dN，其中，根据入射角度获取周期信息的方法如图2A所示实施例中的步骤2一致。进一步，假设各路基模信号需要调制的目标分别为LP11、LP12、……、LP1N。则可以确定各路基模信号对应的少模相位分布函数和光栅相位分布函数分别记为：
Figure PCTCN2015082484-appb-000035
和r1Φ1(x，y)、……、rNΦN(x，y)。
各路基模信号对应的少模光栅相位信息的表达式分别为：
Figure PCTCN2015082484-appb-000036
步骤2，控制器根据各路基模信号对应的少模光栅相位信息产生闪耀光栅的相位全息图。
具体的，在本发明实施例中，将各路基模信号对应的少模光栅相位信息进 行叠加即可产生相位光栅的复合相位信息，其数学表达式可记为：
Figure PCTCN2015082484-appb-000037
同理，根据相位光栅的相位信息，通过全息计算即可得到该相位光栅的相位全息图。该相位全息图里包含各级模式的信息，和其对应的闪耀光栅的信息。
步骤3，控制器将相位全息图传递至相位光栅，更新其相位信息。
其中，上述根据各路基模信号对应的目标模式和入射角度生成相位全息图的步骤，可以由控制器执行预先存储的软件代码来实现，也可以由控制器中包含的各个运算单元通过逻辑运算生成。
请参考图3B所示的控制器的结构图，当控制器310由N个控制单元(即图3B中的310a1、……、310ai、……、310aN)和一个相位全息图产生单元310b组成时，N个控制单元分别与N路入射的基模信号对应。每个控制单元由少模相位产生单元、光栅相位产生单元及少模光栅相位产生单元组成。以控制单元i为例对控制单元中的各个单元之间的关系进行说明，第i路信号对应的目标模式i和入射角度i分别输入至少模相位产生单元310ai1和光栅相位产生单元310ai2，生成少模相位i和光栅相位i；生成的少模相位i和光栅相位i传递至少模光栅相位产生单元310ai3，生成少模光栅相位信息i。少模光栅相位信息i和其他N-1个控制单元生成的N-1个少模光栅相位信息一起传递至相位全息图产生单元310b，生成相位光栅的相位全息图。
可选的，本发明实施例所示的复用装置，还可以包括空间光功率计330，该空间光功率计设置于相位光栅320的出射端，且所述空间光功率计320与所述控制器310电性相连；
所述空间光功率计330，用于测量从所述相位光栅的出射端射出的复用信号中，所述各个少模信号的功率；
所述控制器310，用于在根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计330的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，以实现对所述N路少模信号的功率均衡。
其中，所述控制器310，用于在第1次迭代计算时，确定所述N路基模信 号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
所述控制器310，还用于根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000038
其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000039
为第m路基模信号对应于(x，y)点的少模相位分布函数。
所述控制器310，还用于在所述相位光栅根据对T1(x，y)进行全息计算获得相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率330计测量获得的所述N路少模信号的功率的方差D1；
所述控制器310，用于当所述方差D1小于等于预设的方差阈值时，将α1 m作为第m路基模信号对应的最终的占空比系数；
所述控制器310，用于当所述方差D1大于预设的方差阈值时，进行第2次迭代计算。
所述控制器310，用于在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得相位全息图将所述N路基模信号调制为一路复用信号时，将所述N路少模信号各自的功率除以所述复用信号的总功率，并对得到的各个结果的反比做归一化处理，获得第k次迭代计算时，所述N路基模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000040
其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路基模信号对应的占空比系 数；
所述控制器310，还用于在所述相位光栅根据对Tk(x，y)进行全息计算获得相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计330测量获得的所述N路少模信号的功率的方差Dk；
所述控制器310，用于当所述方差Dk小于等于所述方差阈值时，将αk m作为第m路基模信号对应的最终的占空比系数；
所述控制器310，用于当所述方差Dk大于所述方差阈值时，进行第k+1次迭代计算。
在通信系统中，各个子信道之间的功率均衡十分重要，而在少模复用系统中，各子信道即为各级模式。本发明给出的相位光栅，其复合相位信息是由各个基模信号对应的少模光栅相位直接相加后得到的，在大部分情况下，直接叠加生成的复用后的信号，其各模式之间功率均衡性不是十分理想，本实施例通过引入相位光栅的占空比系数αm对叠加进行优化，以完成复用或解复用后各模式之间的功率均衡。
引入占空比系数αm后的闪耀光栅器件的传输函数可以写作：
Figure PCTCN2015082484-appb-000041
其中，αm系数都满足归一化条件，对αm进行优化以实现功率均衡的步骤如下：
步骤1、控制器初始化αm：设所有模式的占空比系数αm均相同；
步骤2、根据初始化的占空比系统，通过加权系数叠加后的相位表达式产生相位全息图，并更新相位光栅的相位信息。
步骤3、将N路基模信号入射至更新后的相位光栅，测量输出的复用信号中各少模信号的功率，并计算方差。
步骤4、判断方差是否小于门限，小于门限则该组系数即为最终的系数，进一步，其对应的相位光栅的相位即为最终的相位信息。否则，则执行步骤5。
步骤5、取各个模式的少模信号的功率除以总功率的反比做归一化处理，即可得到一组新的占空比系数。根据新的占空比系数执行步骤2。
如此循环，直到得到一组占空比系数其对应的各模式的功率小于门限值。
请参考图3C所示的五模相位光栅的实验测量与模拟效果对比图，其给出了经过优化后的能量均衡的效果，其中，a1-a5实验测量图，b1-b5是模拟计算图，根据图中信息可以看出，经过功率均衡后，输出的各模式信号能量分布较均匀，实验和模拟的数据较为吻合。
可选的，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的基模信号的入射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
进一步，为了更好的完成复用，选择各个模式的对应的光栅周期时，让各个周期之间满足整数倍的关系，即可以保证相位光栅工作时，其各路基模信号入射位置间的距离相等，进一步说，就是使各个信道之间的间隔一致，使各个信道相互之间的干扰更为平均，从而提高传输性能。
图3D给出了可以完成LP21，LP11a，LP01，LP11b及LP31五个模式信号的调制和复用的相位光栅的相位全息图，其中d＝2.832um，则5个模式信号对应的周期分别为2d，d，0，-d，-2d，此时，5个基模信号入射至相位光栅的角度之间的间隔相同。
综上所述，本发明实施例所示的复用装置，通过控制器接收N路基模信号各自对应的入射信息，根据N路基模信号各自对应的入射信息生成相位光栅的相位全息图，并将相位全息图传输给相位光栅，相位光栅根据相位全息图将N路基模信号调制为一路复用信号，复用信号中包含N路少模信号，N路少模信号与N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式，多路基模信号的调制和复用都由同一个光栅器件完成，不需要为每一个基模信号设置一个独立的少模相位片来进行相位转换，对光路的精度要求低，且系统构成简单，占用空间小；此外，本发明实施例所示的模式控制系统，只需要增加入射角度和目标模式即可以扩展信道，便于扩展光互联的容量。
请参考图4A，其示出了本发明一个实施例提供的解复用装置的结构图。其中，该解复用装置可以是图1所示系统中的解复用装置120。如图4A所示，该解复用装置可以包括：路由控制单元410、控制器420以及相位光栅430；
所述控制器420分别与所述路由控制单元410以及所述相位光栅430电性 相连；
所述路由控制单元410，用于向所述控制器420发送N路少模信号各自对应的衍射信息，所述N路少模信号为入射至所述相位光栅430的一路复用信号中包含的信号，所述衍射信息包括当前模式和衍射角度，N≥2，且N为整数；
所述控制器420，用于根据所述N路少模信号各自对应的衍射信息生成所述相位光栅430的相位全息图，并将所述相位全息图传输给所述相位光栅430；
所述相位光栅430，用于根据所述相位全息图将所述复用信号解调为N路基模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路所述基模信号从所述相位光栅430的出射端射出的角度为对应的少模信号的衍射角度。
可选的，所述控制器420，用于在生成所述相位全息图时，根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息，并根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅430的相位全息图。
对于N路少模信号中的每一路少模信号，该少模信号对应的少模光栅相位信息是相位光栅将该少模信号调整为基模信号时，该相位光栅的相位信息。
可选的，所述控制器420，用于在根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息时，对于每一路少模信号，根据所述少模信号的当前模式生成少模相位分布函数，根据所述少模信号的衍射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述少模信号的少模光栅相位信息。
其中，少模相位分布函数是所述少模信号对应的当前模式的相位分布函数；光栅相位分布函数是一个相位光栅将垂直射入的少模信号衍射至对应的衍射角度时，该相位光栅的相位分布函数。
可选的，所述控制器420，用于在根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅430的相位全息图时，根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅430的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
所述复合相位信息表示为：
Figure PCTCN2015082484-appb-000042
其中，a＞0，(x，y)是相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000043
为第m路少模信号对应于(x，y)点的少模相位分布函数。
在本发明实施例中，相位光栅430根据控制器420生成的相位光栅更新自身的相位信息后，将一路复用信号解复用为N路基模信号，并分别从不同的衍射角度射出。基于光路是可逆性原理，如果将这N路基模信号按照各自的衍射角度从原路返回，则该相位光栅430同样可以将该N路基模信号重新调制为N路少模信号，并将N路少模信号复用为一路复用信号。因此，控制器420根据N路少模信号各自对应的衍射信息生成光栅相位430的相位全息图的具体过程，应当与图3A中的控制器310根据N路基模信号各自对应的入射信息生成相位光栅320的相位全息图的具体过程类似，该过程可以参考图3A对应的实施例中的具体描述，此处不再赘述。
其中，上述根据各路少模信号对应的当前模式和衍射角度生成相位全息图的步骤，可以由控制器420执行预先存储的软件代码来实现，也可以由控制器420中包含的各个运算单元通过逻辑运算生成。当上述步骤由控制器420由中包含的各个运算单元通过逻辑运算生成时，控制器420可以包含N个控制单元和一个相位全息图产生单元，N个控制单元分别与N路少模信号对应。每个控制单元由少模相位产生单元、光栅相位产生单元及少模光栅相位产生单元组成，上述各个单元的工作流程与图3B类似，此处不再赘述。
可选的，所述装置还包括：空间光功率计440；所述空间光功率计440设置于所述相位光栅430的出射端，且所述空间光功率计440与所述控制器420电性相连；
所述空间光功率计440，用于测量从所述相位光栅430的出射端射出的所述N个基模信号各自的功率；
所述控制器420，用于在根据所述N路少模信号各自对应的少模光栅相位 信息生成所述相位光栅430的相位全息图时，根据所述空间光功率计440的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，以实现对所述N路基模信号的功率均衡。
可选的，所述控制器420，用于在第1次迭代计算时，确定所述N路少模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
所述控制器420，用于根据以下公式计算所述相位光栅430的复合相位信息；
Figure PCTCN2015082484-appb-000044
其中，a＞0，(x，y)是相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅430的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000045
为第m路少模信号对应于(x，y)点的少模相位分布函数。
所述控制器420，还用于在所述相位光栅430根据对T1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计440测量获得的所述N路基模信号的功率的方差D1；
所述控制器420，用于当所述方差D1小于等于预设的方差阈值时，将α1 m作为第m路少模信号对应的最终的占空比系数；
所述控制器420，用于当所述方差D1大于预设的方差阈值时，进行第2次迭代计算。
可选的，所述控制器420，用于在第k次迭代计算，且所述相位光栅430根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，对所述N路基模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路少模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅430对应于(x，y)点的复合相位信息；k≥2且k为整数；
所述控制器420，用于根据以下公式计算所述相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000046
其中，Tk(x，y)为第k次迭代计算时，所述相位光栅430对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路少模信号对应的占空比系数；
所述控制器420，还用于在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计440测量获得的所述N路基模信号的功率的方差Dk；
所述控制器420，用于当所述方差Dk小于等于所述方差阈值时，将αk m作为第m路少模信号对应的最终的占空比系数；
所述控制器420，用于当所述方差Dk大于所述方差阈值时，进行第k+1次迭代计算。
其中，本发明实施例所示的解复用装置，控制器420根据空间光功率计440的测量结果对各路少模信号各自对应的占空比系数进行调整，以实现对各路基模信号进行功率均衡的方法，与图3A对应实施例中的控制器310根据空间光功率计330的测量结果对各路基模信号各自对应的占空比系数进行调整，以实现对各路少模信号进行功率均衡的方法类似，此处不再赘述。
可选的，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的衍射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
进一步，为了更好的完成解复用，选择各个模式的对应的光栅周期时，让各个周期之间满足整数倍的关系，即可以保证相位光栅工作时，其各路基模信号衍射位置间的距离相等，进一步说，就是使各个信道之间的间隔一致，使各个信道相互之间的干扰更为平均，从而提高传输性能。
此外，本发明实施例所示的解复用装置，维护人员可以通过路由控制单元410任意调节N路基模信号各自的衍射角度，从而实现光信号的路由控制。比如，以该解复用装置为图1所示的模式控制系统中的解复用装置120为例，假设图1中，信号发射单元1对应的基模信号的入射角度与信号接收单元1对应 的基模信号的衍射角度相同，信号发射单元2对应的基模信号的入射角度与信号接收单元2对应的基模信号的衍射角度相同，以此类推，信号发射单元i对应的基模信号的入射角度与信号接收单元i对应的基模信号的衍射角度相同。解复用装置中的路由控制单元可以连接一个可操作界面(图1未示出)，如图4B所示的一种路由控制示意图，维护人员在可操作界面中调节各路基模信号的衍射角度，使信号发射单元i发送的基模信号经过模式控制系统的复用和解复用之后，由信号接收单元i接收，该工作模式可以称为直连模式。或者，如图4C所示的另一种路由控制示意图，维护人员在可操作界面中调节各路基模信号的衍射角度，使信号发射单元i发送的基模信号经过模式控制系统的复用和解复用之后，由信号接收单元j接收，该工作模式可以称为交换模式；假设复用信号包含模式LP11、LP12、……、LP1N，共N个模式的少模信号，且相位光栅的N个输出口分别与N个信号接收单元对应。根据前面所述，空间光通信中，相位光栅的N个输出口可用N个衍射角度来表征，即与信号接收单元1、信号接收单元2、……、信号接收单元N对应的衍射角度，可以表征为Φ1、Φ2、……、ΦN。对于任意一个模式所对应的基模信息，维护人员可根据需要选择其期望输出的输出口或进行传输的信道号，根据信道号即可确定衍射角度。例如LP11所对应的基模信息期望经过第i个输出口进行输出，则图4A中的衍射角度1就等于Φi。同理，根据其他模式所对应的基模信息期望输出的输出口可确定衍射角度2到衍射角度N，以此类推。如图4D所示的模式交换模拟图，以三模相位光栅实现模式交换的过程为例，(a)中的三路模式信息分别为LP11a，LP01和LP11b，(b)中交换了相位光栅的相位全息图中LP11a和LP11b的光栅相位，两个模式就交换了位置，实现了模式的动态调控。
综上所述，本发明实施例所示的解复用装置，路由控制单元向控制器发送N路少模信号对应的衍射信息，控制器根据N路少模信号各自对应的衍射信息生成相位光栅的相位全息图，相位光栅根据相位全息图将复用信号解调为N路基模信号，N路少模信号与N路基模信号一一对应，且每一路基模信号从相位光栅的出射端射出的角度为对应的少模信号的衍射角度，多路基模信号的解调和解复用都由同一个光栅器件完成，对光路的精度要求低，且系统构成简单，占用空间小；此外，本发明实施例所示的模式控制系统，只需要增加衍射角度和少模信号的当前模式即可以扩展信道，便于扩展光互联的容量。
需要说明的是，本发明上述图3A所示的复用装置和图4A所示的解复用装置可以组成图1所示的模式控制系统，也可以单独使用，比如，图3A所示的复用装置与传统的解复用装置组成系统，或者，图4A所示的解复用装置与传统的复用装置组成系统，本发明实施例对此不做限定。
请参考图5，其示出了本发明一个实施例提供的模式控制方法的流程图。其中，该模式控制方法，可以用于如图3A所示的复用装置中，由该复用装置中的控制器来执行。如图5所示，该模式控制方法可以包括：
步骤502，控制器接收N路基模信号各自对应的入射信息，该N路基模信号为同时入射至该相位光栅的基模信号，该入射信息包括目标模式和入射角度，N≥2，且N为整数。
步骤504，控制器根据该N路基模信号各自对应的入射信息生成该相位光栅的相位全息图，并将该相位全息图传输给该相位光栅，由该相位光栅，根据该相位全息图将该N路基模信号调制为一路复用信号，该复用信号中包含N路少模信号，该N路少模信号与该N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式。
可选的，该根据该N路基模信号各自对应的入射信息生成该相位光栅的相位全息图，包括：
该控制器根据该N路基模信号各自对应的入射信息生成该N路基模信号各自对应的少模光栅相位信息，并根据该N路基模信号各自对应的少模光栅相位信息生成该相位光栅的相位全息图；
对于该N路基模信号中的每一路基模信号，该基模信号对应的少模光栅相位信息是该相位光栅将该基模信号调整为对应的少模信号时，该相位光栅的相位信息。
可选的，该根据该N路基模信号各自对应的入射信息生成该N路基模信号各自对应的少模光栅相位信息，包括：
对于每一路基模信号，该控制器根据该基模信号的目标模式生成少模相位分布函数，根据该基模信号的入射角度生成光栅相位分布函数，并根据该少模相位分布函数和该光栅相位分布函数生成该基模信号的少模光栅相位信息；
其中，该少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；光栅相位分布函数是相位光栅将以对应的入射角度射入的基模信号衍射到 与该相位光栅的入射端面垂直的方向时，该相位光栅的相位分布函数。
可选的，该根据该N路基模信号各自对应的少模光栅相位信息生成该相位光栅的相位全息图，包括：
该控制器根据该N路基模信号各自对应的少模光栅相位信息生成该相位光栅的复合相位信息，并对该复合相位信息进行全息计算，获得该相位全息图；
该复合相位信息表示为：
Figure PCTCN2015082484-appb-000047
其中，a＞0，(x，y)是该相位光栅的入射端面上的坐标，T(x，y)为该相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000048
为第m路基模信号对应于(x，y)点的少模相位分布函数。
可选的，该复用装置还包括：空间光功率计；该方法还包括：
该控制器在根据该N路基模信号各自对应的少模光栅相位信息生成该相位光栅的相位全息图时，根据该空间光功率计的测量结果，通过迭代计算确定该N路基模信号各自对应的占空比系数，以实现对该N路少模信号的功率均衡。
可选的，该根据该空间光功率计的测量结果，通过迭代计算确定该N路基模信号各自对应的占空比系数，包括：
在第1次迭代计算时，该控制器确定该N路基模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
该控制器根据以下公式计算该相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000049
其中，a＞0，(x，y)是该相位光栅的入射端面上的坐标，T1(x)为第1次迭代计算时，该相位光栅对应于(x，y)点的复合相位信息，Gm(x)表示 第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000050
为第m路基模信号对应于(x，y)点的少模相位分布函数；
该控制器在该相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将该N路基模信号调制为一路复用信号时，计算该空间光功率计测量获得的该N路少模信号的功率的方差D1；
当该方差D1小于等于预设的方差阈值时，该控制器将α1 m作为第m路基模信号对应的最终的占空比系数；
当该方差D1大于预设的方差阈值时，该控制器进行第2次迭代计算。
可选的，该根据该空间光功率计的测量结果，通过迭代计算确定该N路基模信号各自对应的占空比系数，包括：
在第k次迭代计算，且该相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将该N路基模信号调制为一路复用信号时，该控制器对该N路少模信号各自的功率除以该复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，该N路基模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，该相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
该控制器根据以下公式计算该相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000051
其中，Tk(x，y)为第k次迭代计算时，该相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路基模信号对应的占空比系数；
该控制器在该相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将该N路基模信号调制为一路复用信号时，计算该空间光功率计测量获得的该N路少模信号的功率的方差Dk；
当该方差Dk小于等于该方差阈值时，该控制器将αk m作为第m路基模信号对应的最终的占空比系数；
当该方差Dk大于该方差阈值时，该控制器进行第k+1次迭代计算。
可选的，该N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
其中，对于每一路少模信号，该少模信号对应的光栅周期d与该少模信号对应的基模信号的入射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为该少模信号对应的基模信号的波长。
其中，控制器执行上述方法的具体过程可以参考图3A对应实施例中的描述，此处不再赘述。
综上所述，本发明实施例所示的模式控制方法，通过控制器接收N路基模信号各自对应的入射信息，根据N路基模信号各自对应的入射信息生成相位光栅的相位全息图，并将相位全息图传输给相位光栅，相位光栅根据相位全息图将N路基模信号调制为一路复用信号，复用信号中包含N路少模信号，N路少模信号与N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式，多路基模信号的调制和复用都由同一个光栅器件完成，不需要为每一个基模信号设置一个独立的少模相位片来进行相位转换，对光路的精度要求低，且系统构成简单，占用空间小；此外，本发明实施例所示的模式控制系统，只需要增加入射角度和目标模式即可以扩展信道，便于扩展光互联的容量。
请参考图6，其示出了本发明一个实施例提供的模式控制方法的流程图。其中，该模式控制方法，可以用于如图4A所示的解复用装置中，由该解复用装置中的控制器来执行。如图6所示，该模式控制方法可以包括：
步骤602，控制器接收该路由控制单元发送的N路少模信号对应的衍射信息，该N路少模信号为入射至该相位光栅的一路复用信号中包含的信号，该衍射信息包括当前模式和衍射角度，N≥2，且N为整数。
步骤604，控制器根据该N路少模信号各自对应的衍射信息生成该相位光栅的相位全息图，并将该相位全息图传输给该相位光栅，由该相位光栅根据该相位全息图将该复用信号解调为N路基模信号，该N路少模信号与该N路基模信号一一对应，且每一路该基模信号从该相位光栅的出射端射出的角度为对应的少模信号的衍射角度。
可选的，该根据该N路少模信号各自对应的衍射信息生成该相位光栅的相位全息图，包括：
该控制器根据该N路少模信号各自对应的衍射信息生成该N路少模信号各自对应的少模光栅相位信息，并根据该N路少模信号各自对应的少模光栅相 位信息生成该相位光栅的相位全息图；
对于该N路少模信号中的每一路少模信号，该少模信号对应的少模光栅相位信息是该相位光栅将该少模信号调整为基模信号时，该相位光栅的相位信息。
可选的，该根据该N路少模信号各自对应的衍射信息生成该N路少模信号各自对应的少模光栅相位信息，包括：
对于每一路少模信号，该控制器根据该少模信号的当前模式生成少模相位分布函数，根据该少模信号的衍射角度生成光栅相位分布函数，并根据该少模相位和该光栅相位生成该少模信号的少模光栅相位信息；
其中，该少模相位分布函数是所述少模信号对应的当前模式的相位分布函数；光栅相位分布函数是相位光栅将垂直射入的少模信号衍射至对应的衍射角度时，该相位光栅的相位分布函数。
可选的，该根据该N路少模信号各自对应的少模光栅相位信息生成该相位光栅的相位全息图，包括：
该控制器根据该N路少模信号各自对应的少模光栅相位信息生成该相位光栅的复合相位信息，并对该复合相位信息进行全息计算，获得该相位全息图；
该复合相位信息表示为：
Figure PCTCN2015082484-appb-000052
其中，a＞0，(x，y)是该相位光栅的入射端面上的坐标，T(x，y)为该相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
Figure PCTCN2015082484-appb-000053
为第m路少模信号对应于(x，y)点的少模相位分布函数。
可选的，该解复用装置还包括：空间光功率计；该方法还包括：
该控制器在根据该N路少模信号各自对应的少模光栅相位信息生成该相位光栅的相位全息图时，根据该空间光功率计的测量结果，通过迭代计算确定该N路少模信号各自对应的占空比系数，以实现对该N路基模信号的功率均衡。
可选的，该根据该空间光功率计的测量结果，通过迭代计算确定该N路少模信号各自对应的占空比系数，包括：
在第1次迭代计算时，该控制器确定该N路少模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝…＝α1 N；
该控制器根据以下公式计算该相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000054
其中，a＞0，(x，y)是该相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，该相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应于(x，y)点的光栅相位分布函数，
Figure PCTCN2015082484-appb-000055
Figure PCTCN2015082484-appb-000056
为第m路少模信号对应于(x，y)点的少模相位分布函数；
该控制器在该相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将该复用信号解调为N路基模信号时，计算该空间光功率计测量获得的该N路基模信号的功率的方差D1；
当该方差D1小于等于预设的方差阈值时，该控制器将α1 m作为第m路少模信号对应的最终的占空比系数；
当该方差D1大于预设的方差阈值时，该控制器进行第2次迭代计算。
可选的，该根据该空间光功率计的测量结果，通过迭代计算确定该N路少模信号各自对应的占空比系数，包括：
在第k次迭代计算，且该相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将该复用信号调制为N路基模信号时，该控制器对该N路基模信号各自的功率除以该复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，该N路少模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，该相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
该控制器根据以下公式计算该相位光栅的复合相位信息；
Figure PCTCN2015082484-appb-000057
其中，Tk(x，y)为第k次迭代计算时，该相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路少模信号对应的占空比系数；
该控制器在该相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将该复用信号解调为N路基模信号时，计算该空间光功率计测量获得的该N路基模信号的功率的方差Dk；
当该方差Dk小于等于该方差阈值时，该控制器将αk m作为第m路少模信号对应的最终的占空比系数；
当该方差Dk大于该方差阈值时，该控制器进行第k+1次迭代计算。
可选的，该N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
其中，对于每一路少模信号，该少模信号对应的光栅周期d与该少模信号对应的衍射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为该少模信号对应的基模信号的波长。
其中，控制器执行上述方法的具体过程可以参考图4A对应实施例中的描述，此处不再赘述。
综上所述，本发明实施例所示的模式控制方法，通过控制器接收路由控制单元发送的N路少模信号对应的衍射信息，根据N路少模信号各自对应的衍射信息生成相位光栅的相位全息图，相位光栅根据相位全息图将复用信号解调为N路基模信号，N路少模信号与N路基模信号一一对应，且每一路基模信号从相位光栅的出射端射出的角度为对应的少模信号的衍射角度，多路基模信号的解调和解复用都由同一个光栅器件完成，对光路的精度要求低，且系统构成简单，占用空间小；此外，本发明实施例所示的模式控制系统，只需要增加衍射角度和少模信号的当前模式即可以扩展信道，便于扩展光互联的容量。
本领域普通技术人员可以理解实现上述实施例的全部或部分步骤可以通过硬件来完成，也可以通过程序来指令相关的硬件完成，所述的程序可以存储于一种计算机可读存储介质中，上述提到的存储介质可以是只读存储器，磁盘 或光盘等。
以上所述仅为本发明的较佳实施例，并不用以限制本发明，凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (33)

  1. 一种复用装置，其特征在于，所述复用装置包括：控制器和相位光栅；
    所述控制器和所述相位光栅电性相连；
    所述控制器，用于接收N路基模信号各自对应的入射信息，所述N路基模信号为同时入射至所述相位光栅的基模信号，所述入射信息包括目标模式和入射角度，N≥2，且N为整数；
    所述控制器，用于根据所述N路基模信号各自对应的入射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅；
    所述相位光栅，用于根据所述相位全息图将所述N路基模信号调制为一路复用信号，所述复用信号中包含N路少模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式。
  2. 根据权利要求1所述的装置，其特征在于，
    所述控制器，用于在生成所述相位全息图时，根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息，并根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
    对于所述N路基模信号中的每一路基模信号，所述基模信号对应的少模光栅相位信息是所述相位光栅将所述基模信号调整为对应的少模信号时，所述相位光栅的相位信息。
  3. 根据权利要求2所述的装置，其特征在于，
    所述控制器，用于在根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息时，对于每一路基模信号，根据所述基模信号的目标模式生成少模相位分布函数，根据所述基模信号的入射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述基模信号的少模光栅相位信息；
    其中，所述少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将以对应的入射角度射入的基模信号衍射到与所述相位光栅的入射端面垂直的方向时，所述相位光栅的相位分 布函数。
  4. 根据权利要求2或3所述的装置，其特征在于，
    所述控制器，用于在根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
    所述复合相位信息表示为：
    Figure PCTCN2015082484-appb-100001
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100002
    为第m路基模信号对应于(x，y)点的少模相位分布函数。
  5. 根据权利要求2或3所述的装置，其特征在于，所述装置还包括：空间光功率计；所述空间光功率计设置于所述相位光栅的出射端，且所述空间光功率计与所述控制器电性相连；
    所述空间光功率计，用于测量从所述相位光栅的出射端射出的复用信号中，所述各个少模信号的功率；
    所述控制器，用于在根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，以实现对所述N路少模信号的功率均衡。
  6. 根据权利要求5所述的装置，其特征在于，
    所述控制器，用于在第1次迭代计算时，确定所述N路基模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
    所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100003
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅的对应于(x，y)点复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100004
    为第m路基模信号对应于(x，y)点的少模相位分布函数；
    所述控制器，还用于在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差D1；
    所述控制器，用于当所述方差D1小于等于预设的方差阈值时，将α1 m作为第m路基模信号对应的最终的占空比系数；
    所述控制器，用于当所述方差D1大于预设的方差阈值时，进行第2次迭代计算。
  7. 根据权利要求6所述的装置，其特征在于，
    所述控制器，用于在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，对所述N路少模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路基模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
    所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100005
    其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点 的复合相位信息，αk m为第k次迭代计算时，第m路基模信号对应的占空比系数；
    所述控制器，还用于在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差Dk；
    所述控制器，用于当所述方差Dk小于等于所述方差阈值时，将αk m作为第m路基模信号对应的最终的占空比系数；
    所述控制器，用于当所述方差Dk大于所述方差阈值时，进行第k+1次迭代计算。
  8. 根据权利要求1至7任一所述的装置，其特征在于，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
    其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的基模信号的入射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
  9. 一种解复用装置，其特征在于，所述解复用装置包括：路由控制单元、控制器以及相位光栅；
    所述控制器分别与所述路由控制单元以及所述相位光栅电性相连；
    所述路由控制单元，用于向所述控制器发送N路少模信号对应的衍射信息，所述N路少模信号为入射至所述相位光栅的一路复用信号中包含的信号，所述衍射信息包括当前模式和衍射角度，N≥2，且N为整数；
    所述控制器，用于根据所述N路少模信号各自对应的衍射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅；
    所述相位光栅，用于根据所述相位全息图将所述复用信号解调为N路基模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路所述基模信号从所述相位光栅的出射端射出的角度为对应的少模信号的衍射角度。
  10. 根据权利要求9所述的装置，其特征在于，
    所述控制器，用于在生成所述相位全息图时，根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息，并根据 所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
    对于所述N路少模信号中的每一路少模信号，所述少模信号对应的少模光栅相位信息是所述相位光栅将所述少模信号调整为基模信号时，所述相位光栅的相位信息。
  11. 根据权利要求10所述的装置，其特征在于，
    所述控制器，用于在根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息时，对于每一路少模信号，根据所述少模信号的当前模式生成少模相位分布函数，根据所述少模信号的衍射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述少模信号的少模光栅相位信息；
    其中，所述少模相位分布函数是所述少模信号对应的当前模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将垂直射入的少模信号衍射至对应的衍射角度时，所述相位光栅的相位分布函数。
  12. 根据权利要求9或10所述的装置，其特征在于，
    所述控制器，用于在根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
    所述复合相位信息表示为：
    Figure PCTCN2015082484-appb-100006
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100007
    为第m路少模信号对应于(x，y)点的少模相位分布函数。
  13. 根据权利要求9或10所述的装置，其特征在于，所述装置还包括：空间光功率计；所述空间光功率计设置于所述相位光栅的出射端，且所述空间光功率计与所述控制器电性相连；
    所述空间光功率计，用于测量从所述相位光栅的出射端射出的所述N个基模信号各自的功率；
    所述控制器，用于在根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，以实现对所述N路基模信号的功率均衡。
  14. 根据权利要求13所述的装置，其特征在于，
    所述控制器，用于在第1次迭代计算时，确定所述N路少模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
    所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100008
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100009
    为第m路少模信号对应于(x，y)点的少模相位分布函数；
    所述控制器，还用于在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差D1；
    所述控制器，用于当所述方差D1小于等于预设的方差阈值时，将α1 m作为第m路少模信号对应的最终的占空比系数；
    所述控制器，用于当所述方差D1大于预设的方差阈值时，进行第2次迭代计算。
  15. 根据权利要求14所述的装置，其特征在于，
    所述控制器，用于在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，对所述N路基模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路少模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
    所述控制器，用于根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100010
    其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路少模信号对应的占空比系数；
    所述控制器，还用于在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差Dk；
    所述控制器，用于当所述方差Dk小于等于所述方差阈值时，将αk m作为第m路少模信号对应的最终的占空比系数；
    所述控制器，用于当所述方差Dk大于所述方差阈值时，进行第k+1次迭代计算。
  16. 根据权利要求9至15任一所述的装置，其特征在于，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
    其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的衍射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
  17. 一种模式控制方法，其特征在于，用于复用装置中，所述复用装置包 括：控制器和相位光栅，所述方法包括：
    所述控制器接收N路基模信号各自对应的入射信息，所述N路基模信号为同时入射至所述相位光栅的基模信号，所述入射信息包括目标模式和入射角度，N≥2，且N为整数；
    所述控制器根据所述N路基模信号各自对应的入射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅，由所述相位光栅，根据所述相位全息图将所述N路基模信号调制为一路复用信号，所述复用信号中包含N路少模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路少模信号的模式为对应的基模信号的目标模式。
  18. 根据权利要求17所述的方法，其特征在于，所述根据所述N路基模信号各自对应的入射信息生成所述相位光栅的相位全息图，包括：
    所述控制器根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息，并根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
    对于所述N路基模信号中的每一路基模信号，所述基模信号对应的少模光栅相位信息是所述相位光栅将所述基模信号调整为对应的少模信号时，所述相位光栅的相位信息。
  19. 根据权利要求18所述的方法，其特征在于，所述根据所述N路基模信号各自对应的入射信息生成所述N路基模信号各自对应的少模光栅相位信息，包括：
    对于每一路基模信号，所述控制器根据所述基模信号的目标模式生成少模相位分布函数，根据所述基模信号的入射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述基模信号的少模光栅相位信息；
    其中，所述少模相位分布函数是所述基模信号对应的目标模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将以对应的入射角度射入的基模信号衍射到与所述相位光栅的入射端面垂直的方向时，所述相位光栅的相位分布函数。
  20. 根据权利要求18或19所述的方法，其特征在于，所述根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图，包括：
    所述控制器根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
    所述复合相位信息表示为：
    Figure PCTCN2015082484-appb-100011
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100012
    为第m路基模信号对应于(x，y)点的少模相位分布函数。
  21. 根据权利要求18或19所述的方法，其特征在于，所述复用装置还包括：空间光功率计；所述方法还包括：
    所述控制器在根据所述N路基模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，以实现对所述N路少模信号的功率均衡。
  22. 根据权利要求21所述的方法，其特征在于，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，包括：
    在第1次迭代计算时，所述控制器确定所述N路基模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
    所述控制器根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100013
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x)为第1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，Gm(x)表示第m路基模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路基模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100014
    为第m路基模信号对应于(x，y)点的少模相位分布函数；
    所述控制器在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差D1；
    当所述方差D1小于等于预设的方差阈值时，所述控制器将α1 m作为第m路基模信号对应的最终的占空比系数；
    当所述方差D1大于预设的方差阈值时，所述控制器进行第2次迭代计算。
  23. 根据权利要求22所述的方法，其特征在于，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路基模信号各自对应的占空比系数，包括：
    在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，所述控制器对所述N路少模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路基模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
    所述控制器根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100015
    其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点 的复合相位信息，αk m为第k次迭代计算时，第m路基模信号对应的占空比系数；
    所述控制器在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述N路基模信号调制为一路复用信号时，计算所述空间光功率计测量获得的所述N路少模信号的功率的方差Dk；
    当所述方差Dk小于等于所述方差阈值时，所述控制器将αk m作为第m路基模信号对应的最终的占空比系数；
    当所述方差Dk大于所述方差阈值时，所述控制器进行第k+1次迭代计算。
  24. 根据权利要求17至23任一所述的方法，其特征在于，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
    其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的基模信号的入射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
  25. 一种模式控制方法，其特征在于，用于解复用装置中，所述解复用装置包括：路由控制单元、控制器和相位光栅，所述方法包括：
    所述控制器接收所述路由控制单元发送的N路少模信号对应的衍射信息，所述N路少模信号为入射至所述相位光栅的一路复用信号中包含的信号，所述衍射信息包括当前模式和衍射角度，N≥2，且N为整数；
    所述控制器根据所述N路少模信号各自对应的衍射信息生成所述相位光栅的相位全息图，并将所述相位全息图传输给所述相位光栅，由所述相位光栅根据所述相位全息图将所述复用信号解调为N路基模信号，所述N路少模信号与所述N路基模信号一一对应，且每一路所述基模信号从所述相位光栅的出射端射出的角度为对应的少模信号的衍射角度。
  26. 根据权利要求25所述的方法，其特征在于，所述根据所述N路少模信号各自对应的衍射信息生成所述相位光栅的相位全息图，包括：
    所述控制器根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息，并根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图；
    对于所述N路少模信号中的每一路少模信号，所述少模信号对应的少模光栅相位信息是所述相位光栅将所述少模信号调整为基模信号时，所述相位光栅的相位信息。
  27. 根据权利要求26所述的方法，其特征在于，所述根据所述N路少模信号各自对应的衍射信息生成所述N路少模信号各自对应的少模光栅相位信息，包括：
    对于每一路少模信号，所述控制器根据所述少模信号的当前模式生成少模相位分布函数，根据所述少模信号的衍射角度生成光栅相位分布函数，并根据所述少模相位分布函数和所述光栅相位分布函数生成所述少模信号的少模光栅相位信息；
    其中，所述少模相位分布函数是所述少模信号对应的当前模式的相位分布函数；所述光栅相位分布函数是所述相位光栅将垂直射入的少模信号衍射至对应的衍射角度时，所述相位光栅的相位分布函数。
  28. 根据权利要求26或27所述的方法，其特征在于，所述根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图，包括：
    所述控制器根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的复合相位信息，并对所述复合相位信息进行全息计算，获得所述相位全息图；
    所述复合相位信息表示为：
    Figure PCTCN2015082484-appb-100016
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T(x，y)为所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100017
    为第m路少模信号对应于(x，y)点的少模相位分布函数。
  29. 根据权利要求26或27所述的方法，其特征在于，所述解复用装置还包括：空间光功率计；所述方法还包括：
    所述控制器在根据所述N路少模信号各自对应的少模光栅相位信息生成所述相位光栅的相位全息图时，根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，以实现对所述N路基模信号的功率均衡。
  30. 根据权利要求29所述的方法，其特征在于，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数，包括：
    在第1次迭代计算时，所述控制器确定所述N路少模信号对应的占空比系数为α1 m；m＝1，2，……，N；且α1 1＝α1 2＝……＝α1 N；
    所述控制器根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100018
    其中，a＞0，(x，y)是所述相位光栅的入射端面上的坐标，T1(x，y)为第1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，Gm(x，y)表示第m路少模信号对应于(x，y)点的少模光栅相位信息，rmΦ(x，y)为(x，y)点处，第m路少模信号对应的光栅相位分布函数，
    Figure PCTCN2015082484-appb-100019
    为第m路少模信号对应于(x，y)点的少模相位分布函数；
    所述控制器在所述相位光栅根据对T1(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差D1；
    当所述方差D1小于等于预设的方差阈值时，所述控制器将α1 m作为第m路少模信号对应的最终的占空比系数；
    当所述方差D1大于预设的方差阈值时，所述控制器进行第2次迭代计算。
  31. 根据权利要求30所述的方法，其特征在于，所述根据所述空间光功率计的测量结果，通过迭代计算确定所述N路少模信号各自对应的占空比系数， 包括：
    在第k次迭代计算，且所述相位光栅根据对Tk-1(x，y)进行全息计算获得的相位全息图将所述复用信号调制为N路基模信号时，所述控制器对所述N路基模信号各自的功率除以所述复用信号的总功率的反比做归一化处理，获得第k次迭代计算时，所述N路少模信号各自的占空比系数；Tk-1(x，y)为第k-1次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息；k≥2且k为整数；
    所述控制器根据以下公式计算所述相位光栅的复合相位信息；
    Figure PCTCN2015082484-appb-100020
    其中，Tk(x，y)为第k次迭代计算时，所述相位光栅对应于(x，y)点的复合相位信息，αk m为第k次迭代计算时，第m路少模信号对应的占空比系数；
    所述控制器在所述相位光栅根据对Tk(x，y)进行全息计算获得的相位全息图将所述复用信号解调为N路基模信号时，计算所述空间光功率计测量获得的所述N路基模信号的功率的方差Dk；
    当所述方差Dk小于等于所述方差阈值时，所述控制器将αk m作为第m路少模信号对应的最终的占空比系数；
    当所述方差Dk大于所述方差阈值时，所述控制器进行第k+1次迭代计算。
  32. 根据权利要求25至31任一所述的方法，其特征在于，所述N路少模信号对应的光栅周期各不相同，且相互之间满足整数倍关系；
    其中，对于每一路少模信号，所述少模信号对应的光栅周期d与所述少模信号对应的衍射角度θ满足以下条件：Sinθ＝λ/(2*d)；λ为所述少模信号对应的基模信号的波长。
  33. 一种模式控制系统，其特征在于，所述系统包括：
    如权利要求1至8任一所述的复用装置，以及，如权利要求9至16任一所述的解复用装置。
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