WO2014148027A1 - Dispositif de commande de lumière, dispositif de communication de lumière spatiale l'utilisant, et procédé de commande de lumière - Google Patents

Dispositif de commande de lumière, dispositif de communication de lumière spatiale l'utilisant, et procédé de commande de lumière Download PDF

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WO2014148027A1
WO2014148027A1 PCT/JP2014/001493 JP2014001493W WO2014148027A1 WO 2014148027 A1 WO2014148027 A1 WO 2014148027A1 JP 2014001493 W JP2014001493 W JP 2014001493W WO 2014148027 A1 WO2014148027 A1 WO 2014148027A1
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Prior art keywords
wavefront
light
target
signal
unit
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PCT/JP2014/001493
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English (en)
Japanese (ja)
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青木　一彦
想 西村
柳田　美穂
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日本電気株式会社
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Priority to JP2015506603A priority Critical patent/JP6274204B2/ja
Publication of WO2014148027A1 publication Critical patent/WO2014148027A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/0025—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
    • H04B10/112—Line-of-sight transmission over an extended range
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
    • H04B10/118—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum specially adapted for satellite communication

Definitions

  • the present invention relates to an optical control device, an optical space communication device using the same, and an optical control method, and in particular, an optical control device that suppresses an optical surge without reducing reception sensitivity in optical space communication, and an optical space using the same.
  • the present invention relates to a communication device and an optical control method.
  • laser light is used to communicate a space between moving bodies such as artificial satellites and aircraft, between a moving body and a ground station, or between ground stations.
  • optical space communication it is necessary to align the optical axes of the light beams for transmission between the receiver and the transmitter in order to transmit communication signals.
  • the light beam for transmission spreads at a spread angle corresponding to the wavelength of the laser light. Further, when the light beam passes through the atmosphere, the light intensity is attenuated according to the propagation distance in the atmosphere due to atmospheric absorption or scattering. As a result, the light intensity received by the receiver decreases as the distance from the transmitter increases, and thus it is necessary to improve reception sensitivity.
  • the deflection mechanism provided in the repeater between the transmitter and the receiver controls the deflection of the light beam, while the optical beam amplifier provided in front of the light receiving element
  • An optical space transmission device for amplification is described in Patent Document 1.
  • the optical space transmission device of Patent Literature 1 includes a repeater and a receiver.
  • a converging lens that condenses the light beam from the transmitter, an optical fiber on which the condensed light beam is incident, a collimator lens that collimates the light beam emitted from the optical fiber, And a deflection mechanism provided on the collimator lens side of the optical fiber.
  • a converging lens that collects the light beam from the transmitter or the repeater, an optical fiber on which the collected light beam is incident, and an optical fiber that couples the light beam in the optical fiber and the excitation light It consists of a coupler.
  • the receiver includes an optical fiber amplifier into which the two coupled lights are incident, and a reproduction signal apparatus into which the light beam amplified by the optical fiber amplifier is incident.
  • the light beam emitted from the transmitter is collected by the converging lens of the repeater and enters the optical fiber.
  • the light beam emitted from the optical fiber becomes parallel light by the collimator lens and propagates to the receiver.
  • the collimator lens side of the optical fiber is displaced by a deflection mechanism in a plane perpendicular to the optical axis of the collimator lens so as to enter the end of the optical fiber in the receiver.
  • the light beam propagated from the transmitter or the repeater is collected by the converging lens in the receiver and enters the optical fiber.
  • the light beam incident on the optical fiber coupler is combined with the pump light from the pump light source, the light beam is amplified by the optical fiber amplifier, and is incident on the reproduction signal device. Thereby, it is possible to correct the optical axis shift of the light beam with respect to the optical axis of the receiver and to improve the lowered light receiving sensitivity.
  • Patent Document 2 describes an optical space communication device that corrects wavefront distortion of incident light using a curvature mirror and amplifies received incident light using an optical receiver including an optical fiber amplifier. Yes.
  • the optical space communication device of Patent Document 2 includes a curvature mirror, a plane mirror, a lens, an optical receiver including an optical fiber amplifier, a control unit, and a drive unit, and operates as follows. To do.
  • the wavefront distortion of the incident light is corrected to the output light having a flat wavefront.
  • the emitted light is reflected by the plane mirror toward the lens and is collected on the optical receiver by the lens.
  • the light collected on the optical fiber amplifier provided by the optical receiver is amplified and a light intensity signal is detected.
  • the control unit outputs a drive signal based on the light intensity signal, and the drive unit displaces the curvature distribution of the mirror surface of the curvature mirror based on the drive signal. Thereby, the loss of the light condensed on the optical fiber amplifier is suppressed.
  • EDFA ErbiumEDDoped Fiber Amplifier
  • EDFA ErbiumEDDoped Fiber Amplifier
  • the received light may be momentarily interrupted by an obstacle or the like between the transmitter and the receiver.
  • the input light of the optical fiber amplifier is lost, so that the excitation light accumulates and the energy level of the optical fiber amplifier becomes excessive.
  • the received light recovers in this state, there is a problem that abnormally strong light is output from the optical fiber amplifier due to a large amplification gain, and the photoelectric conversion element in the receiver is damaged.
  • This abnormally strong light is called a light surge, and in the following explanation, the abnormally strong light is described as a light surge.
  • the transmittance of the optical switch arranged on the output side of the communication beam of the optical fiber amplifier is reduced based on the detection of instantaneous interruption of the communication beam input to the optical fiber amplifier.
  • An object of the present invention is to provide a light control device that solves the above-described problem that the cost is increased and the control is complicated when the influence of an optical surge is avoided, and an optical space communication device using the same. And providing a light control method.
  • the light control device of the present invention includes a wavefront modulation unit that controls a wavefront of incident light, a detection unit that acquires intensity information of the incident light, a control unit that determines a target wavefront based on the intensity information, and the incident light Wavefront control means for controlling the wavefront modulation means so that the wavefront is substantially equal to the target wavefront.
  • the light control method of the present invention acquires phase information and intensity information of incident light, determines a target wavefront of the incident light based on the intensity information, and the wavefront of the incident light is substantially the same as the target wavefront.
  • the wavefront of the incident light is controlled so as to be equal.
  • the optical space communication device and the light control method using the same it is possible to avoid the influence of the light surge without increasing the cost and complicating the control.
  • FIG. 1 is a block diagram showing a configuration of a light control apparatus 1 according to the first embodiment of the present invention.
  • the light control device 1 controls the light beam incident on the optical amplification unit 30 at the subsequent stage and suppresses the light surge input to the light receiving unit 35.
  • the light control device 1 includes a detection unit 9, a control unit 11, a wavefront control unit 13, and a wavefront modulation unit 21.
  • the detection unit 9 receives received light that is a light beam incident on the light control device 1, specifically, a part of the light beam (received light) emitted from the wavefront modulation unit 21. Then, the received light intensity that is the intensity information of the light beam is detected, and the received light intensity information signal based on the received light intensity is output to the control unit 11.
  • the received light intensity information signal is a signal that changes in accordance with a change in received light intensity.
  • the control unit 11 receives the light reception intensity information signal from the detection unit 9, detects a decrease in the light reception intensity from the light reception intensity information signal, and determines a target wavefront based thereon.
  • a target aberration signal including information on the target wavefront is output to the wavefront control unit 13, and an optical amplification control signal for stopping or reducing light amplification is output to the subsequent optical amplification unit 30.
  • control unit 11 When the control unit 11 detects a change in the received light intensity included in the received light intensity information signal, the control unit 11 targets information on wavefront aberration that greatly disturbs the wavefront so that the ratio of the light beam input to the optical amplifying unit 30 decreases. It is added to the aberration signal. After that, the wavefront modulation unit 21 gives information on wavefront aberration that gradually reduces the wavefront disturbance.
  • the light beam input to the wavefront modulation unit 21 and further to the optical amplification unit 30 is momentarily interrupted.
  • the light reception intensity decreases and the light reception intensity light shielding time differs.
  • a predetermined threshold is provided for the received light intensity information signal.
  • the threshold value is the ratio of the size of the obstacle to the cross section intersecting the optical axis of the light beam, and the wavefront modulation unit 21 It is determined in advance from the magnitude of the light surge accompanying the momentary interruption of the light beam incident on the light. When the received light intensity information signal is below this threshold, it is detected that the received light intensity has decreased.
  • control unit 11 When the control unit 11 detects the decrease in the received light intensity, the control unit 11 adds information on large wavefront aberrations that can be controlled by the wavefront modulation unit 21 to the target aberration signal and outputs the information to the wavefront control unit 13.
  • the control unit 11 gradually adds information on the wavefront aberration smaller than the wavefront aberration at that time to the target aberration signal to thereby add the wavefront control unit. 13 to output.
  • the information of wavefront aberration which decreases stepwise is added to the target aberration signal until the large wavefront aberration first applied to the light beam becomes zero.
  • the wavefront control unit 13 receives the target aberration signal from the control unit 11 and outputs a phase information signal of the light beam compensated by the wavefront modulation unit 21. Specifically, based on the information on the wavefront aberration included in the target aberration signal, a two-dimensional phase distribution of a cross section perpendicular to the optical axis of the light beam is calculated, and the information is output to the wavefront modulation unit 21 as a phase information signal. To do. That is, when information on large wavefront aberration that can be controlled by the wavefront modulation unit 21 is included in the target aberration signal, a phase information signal that greatly disturbs the wavefront is output to the wavefront modulation unit 21. When the target aberration signal includes wavefront aberration information that gradually decreases, a phase information signal corresponding to the information is output to the wavefront modulation unit 21.
  • the wavefront modulation unit 21 compensates for fluctuations in the wavefront of the light beam due to atmospheric fluctuations. Further, when an instantaneous interruption of the light beam occurs, the spatial phase of the light beam incident on the light control device 1 is modulated and emitted based on the phase information signal from the wavefront control unit 13. That is, the phase of light in a plurality of regions in a two-dimensional plane intersecting the traveling direction of the light beam (the direction incident on the wavefront modulation unit 21) is controlled, and the light beam is emitted or reflected to the light amplification unit 30.
  • the wavefront modulation unit 21 can be a deformable mirror, a liquid crystal panel, or the like.
  • the wavefront modulation unit 21 gives a large wavefront aberration to the light beam based on the signal.
  • the wavefront of the light beam is greatly disturbed, and the ratio of the light beam output to the optical amplifying unit 30 is reduced.
  • the wavefront aberration of the light beam is reduced stepwise based on the signal. Accordingly, the ratio of the light beam output to the optical amplification unit 30 increases stepwise.
  • the light amplification of the light amplifying unit 30 is resumed, whereby the light beam incident on the light amplifying unit 30 is amplified, and the light receiving unit 35 receives the communication signal included in the light beam. To detect.
  • FIG. 2 is a flowchart for explaining a light control method using the light control device 1
  • FIG. 3 is a diagram showing a relationship between a target aberration signal (target wavefront) and a received light intensity information signal (intensity information).
  • FIG. 3 shows a case where the relationship between the target aberration signal and the received light intensity information signal changes linearly, but is not limited to this. Any relationship may be used as long as the target aberration increases and the received light intensity decreases. For example, the relationship between the target aberration signal and the received light intensity information signal may change in a curved line.
  • control unit 11 monitors whether the received light intensity information signal input from detection unit 9 is equal to or less than a threshold value (step S1). When larger than the threshold value (when Step S1 is No), the monitoring of the received light intensity information signal is continued. On the other hand, if it is equal to or less than the threshold value (when Step S1 is Yes), the control unit 11 outputs a target aberration signal that increases wavefront aberration (having information on large wavefront aberration) to the wavefront control unit 13 (Step S2). Specifically, as shown in FIG. 3, a value A N larger than the target aberration signal A 0 when the received light intensity information signal is a threshold value is output.
  • control unit 11 outputs an optical amplification control signal for reducing (stopping or reducing) the amplification of light to the optical amplification unit 30 (step S3). Subsequently, the control unit 11 outputs a target aberration signal for reducing the wavefront aberration (having information for gradually reducing the wavefront aberration) to the wavefront control unit 13 (step S4). At this time, the value of the target aberration signal output to the wavefront control unit 13 is a value A N ⁇ 1 between A N and A 0 . Thereafter, the control unit 11 monitors whether or not the received light intensity information signal input from the detection unit 9 is greater than or equal to a threshold value (step S5).
  • Step S5 When smaller than the threshold value (when Step S5 is No), the process returns to Step S4. At this time, in step S4, the control unit 11 outputs a target aberration signal to which the value A N ⁇ 2 smaller than A N ⁇ 1 and larger than A 0 is given to the wavefront control unit 13. In this way, the target aberration signal to which a value that gradually approaches A 0 from A N is output to the wavefront control unit 13.
  • Step S6 the operation time from step S1 to step S5 of the control unit 11 is set to be longer than the time during which the light beam is momentarily interrupted.
  • the wavefront modulation unit 21 that performs wavefront compensation of the light beam accompanying the fluctuation of the atmosphere to the optical amplification unit 30 as the received light intensity information signal becomes less than the threshold value. Decreasing the input light beam. At the same time, the amplification of the light beam of the light amplifying unit 30 is stopped or reduced. Further, by increasing the light beam input from the wavefront modulation unit 21 to the optical amplification unit 30 by changing the wavefront aberration in a stepwise manner until the received light intensity information signal becomes equal to or greater than the threshold value, the light of the optical amplification unit 30 is increased. Restore beam amplification. Thereby, a new optical element is not required for suppression of the optical surge, and control complexity can be suppressed while suppressing an increase in cost including assembly work.
  • the light beam input to the wavefront modulation unit 21 is momentarily interrupted, it is possible to suppress the occurrence of an optical surge generated in the optical amplification unit 30.
  • the instantaneous interruption of the light beam is recovered, the light beam is efficiently input from the wavefront modulation unit 21 to the optical amplification unit 30 and the light amplification of the optical amplification unit 30 is also recovered. A decrease in sensitivity can be prevented.
  • FIG. 4 is a block diagram showing the configuration of the light control apparatus 2 according to the second embodiment of the present invention.
  • the light control apparatus 2 includes a wavefront calculation unit 14, a light dividing unit 22, a light condensing unit 31, an optical fiber 32, and light in addition to the configuration of the first embodiment.
  • a fiber amplifier 33, an excitation light source 34, and a light receiving unit 35 are provided.
  • the light intensity calculating part 10 and the wavefront sensor 23 which comprise the detection part 9 of 1st Embodiment are provided, the target wavefront calculating part 12 and the wavefront calculating part 14 which comprise the wavefront control part 13 of 1st Embodiment.
  • the light splitting unit 22 splits the light beam subjected to phase modulation into two optical paths.
  • the optical path toward the wavefront sensor 23 and the optical path toward the light condensing unit 31 are divided.
  • a half mirror, a prism, or a polarization beam splitter can be used. Note that the intensity ratios of the divided optical paths are not necessarily equal.
  • the wavefront sensor 23 includes a camera unit such as a CCD (Charge Coupled Device) element or a CMOS (Complementary Metal Oxide Semiconductor) element as a detection unit. Then, the spatial phase distribution of one of the light beams divided by the light dividing unit 22 is measured, and information on the phase distribution is converted into an electrical signal and output. Specifically, the phase information that is information on the phase or the gradient of the phase in a plurality of regions in a two-dimensional plane intersecting the traveling direction of the light beam (the direction of incidence on the wavefront sensor 23) is converted into an electric signal to generate a wavefront. The result is output to the calculation unit 14.
  • a camera unit such as a CCD (Charge Coupled Device) element or a CMOS (Complementary Metal Oxide Semiconductor) element as a detection unit.
  • the spatial phase distribution of one of the light beams divided by the light dividing unit 22 is measured, and information on the phase distribution is converted into an electrical signal and output. Specifically, the
  • the wavefront sensor 23 measures (or detects) the spatial intensity distribution of the incident light beam, converts the intensity distribution information into an electrical signal, and outputs it. Specifically, information on the intensity or gradient of intensity in a plurality of regions in a two-dimensional plane intersecting the traveling direction of the light beam (the direction of incidence on the wavefront sensor 23) is converted into an electrical signal and sent to the light intensity calculation unit 10. Output.
  • a Shack-Hartmann wavefront sensor, a wavefront curvature sensor, or the like can be used as the wavefront sensor 23 as described above.
  • the light intensity calculation unit 10 calculates the received light intensity (intensity information) from the electric signal related to the intensity or intensity gradient information in the two-dimensional plane measured (or detected) by the wavefront sensor 23, and the calculated electric signal of the information Is output to the control unit 11 as a received light intensity information signal.
  • the received light intensity information signal is a signal that changes in accordance with a change in received light intensity.
  • the wavefront calculation unit 14 calculates the wavefront of the light beam from the electrical signal related to the phase or phase slope information (phase information) output from the wavefront sensor 23, and outputs the calculated electrical signal to the wavefront compensation calculation unit 15. .
  • the electrical signal output to the wavefront compensation calculation unit 15 is a signal corresponding to the two-dimensional phase information of the light beam incident on the wavefront sensor 23. It is.
  • the control unit 11 sets a target aberration signal that the wavefront modulation unit 21 gives to the phase of the light beam, and outputs the target aberration signal to the target wavefront calculation unit 12. Further, the target wavefront calculator 12 outputs a phase information signal including information on a two-dimensional phase distribution corresponding to the target aberration based on the input target aberration signal.
  • a light condensing unit 31 to be described later changes a condensing spot formed on the core of the optical fiber 32.
  • the target aberration signal is set so as to change the shape, size, and position of the condensing spot on the incident surface of the optical fiber 32, and is guided into the core diameter on the incident surface of the optical fiber 32.
  • the target aberration signal is set so as to change the shape, size, and position of the focused spot in stages.
  • the wavefront compensation calculation unit 15 calculates the difference between the phase information signal input from the target wavefront calculation unit 12 and the electrical signal related to the calculation information of the wavefront of the light beam input from the wavefront calculation unit 14, and calculates from the information
  • the control signal of the wavefront modulation unit 21 is output. Specifically, the wavefront modulation unit 21 is feedback-controlled so that the difference between the phase information related to the target wavefront of the light beam and the phase information related to the wavefront of the light beam measured by the wavefront sensor 23 becomes small. As a result, the wavefront of the light beam emitted from the wavefront modulation unit 21 is changed to the wavefront of the desired light beam.
  • the calculation in the wavefront compensation calculation unit is a matrix calculation including a conversion matrix.
  • the light condensing unit 31 condenses the light beam traveling in the direction of the optical fiber 32 among the light beams divided by the light dividing unit 22, and the collected light beam enters the core of the optical fiber 32.
  • the focused spot diameter on the optical fiber is close to the core diameter of the optical fiber and ideally equal to the core diameter, the desired optical communication performance can be achieved.
  • the optical fiber 32 is connected to the optical fiber amplifier 33.
  • the optical fiber amplifier 33 is an optical element that improves the light receiving sensitivity of the communication signal of the optical space communication, and changes the intensity of the light beam incident and guided to the optical fiber 32 according to the excitation light injected from the excitation light source 34. And output to the light receiving unit 35. Specifically, when the excitation light from the excitation light source 34 is injected into the optical fiber amplifier, the light beam incident from the optical fiber 32 is amplified and emitted to the light receiving unit 35. When the excitation light is not injected into the optical fiber amplifier, the light beam incident from the optical fiber 32 is emitted to the light receiving unit without being amplified.
  • the light receiving unit 35 is a photoelectric conversion element such as a photodiode, converts the incident light beam from the optical fiber amplifier 33 into an electrical signal, and outputs it as a received signal to a subsequent circuit.
  • the received light intensity information signal detected by the wavefront sensor 23 decreases.
  • the size, shape, or position of the focused beam with respect to the core on the incident surface of the optical fiber 32 changes or moves, and the coupling efficiency of the light beam incident on the optical fiber decreases.
  • the received light intensity information signal detected by the wavefront sensor 23 is increased stepwise.
  • the size, shape, or position of the focused beam is changed or moved to the diameter and position of the core on the incident surface of the optical fiber 32, and the coupling efficiency of the light beam incident on the optical fiber 32 is improved.
  • the light control device 2 is similar to the first embodiment in that the wavefront modulation unit can be used even if there is a wavefront distortion or wavefront fluctuation of the incident light beam.
  • the wavefront of the light beam is compensated by 21 and the coupling efficiency of the light beam incident on the optical fiber 32 is maintained. Thereby, the fall of the light reception sensitivity at the time of optical communication can be suppressed, and desired communication performance can be achieved.
  • FIG. 5 is a flowchart for explaining the operation of the light control device 2
  • FIG. 6 is a diagram showing the relationship between the target aberration signal and the received light intensity information signal.
  • the received light intensity information signal decreases as the target aberration signal based on spherical aberration increases, and the received light intensity information signal increases as the target aberration signal decreases based on spherical aberration.
  • FIG. 6 shows the case where the target aberration signal is spherical aberration
  • the present invention is not limited to this, and other aberrations such as coma and astigmatism may be used.
  • it may be a wavefront corresponding to an arbitrary coefficient when the wavefront is expanded by a Zernike polynomial, or may be a combination of wavefronts combining them.
  • the control unit 11 has a light reception intensity information signal (intensity information) from the light intensity calculation unit 10 based on the light reception intensity measured by the wavefront sensor 23 equal to or less than a threshold value. Whether or not there is is monitored (step S11).
  • the received light intensity information signal is larger than the threshold (when Step S1 is No)
  • the received light intensity information signal is continuously monitored.
  • the control unit 11 outputs a target aberration signal that increases spherical aberration (having information on large spherical aberration) to the target wavefront calculation unit 12. (Step S12).
  • a value B N greater than the wavefront aberration information B 0 of the target aberration signal when the received light intensity information signal is a threshold value is output.
  • the control unit 11 outputs an optical amplification control signal for reducing (stopping or reducing) the light amplification to the excitation light source 34 (step S13).
  • the control unit 11 outputs a target aberration signal for reducing the spherical aberration (having information for gradually reducing the spherical aberration) to the target wavefront calculation unit 12 (step S14).
  • the value of the target aberration signal output to the target wavefront calculator 12 is a value B N ⁇ 1 between B N and B 0 .
  • the controller 11 monitors whether or not the received light intensity information signal input from the light intensity calculator 10 is equal to or greater than a threshold (step S15). In other words, it is monitored whether the coupling efficiency of the light beam focused on the optical fiber 32 is equal to or higher than a predetermined threshold value.
  • Step S14 the control unit 11 outputs the target aberration signal to which the value B N ⁇ 2 smaller than B N ⁇ 1 and larger than B 0 is given to the target wavefront calculation unit 12.
  • the target wavefront computing unit 12 applies the phase distribution to the light beam created based on this signal every time the information B N , B N-1 , B N-2 added to the target aberration signal is input. Is output to the wavefront compensation calculation unit 15.
  • the wavefront compensation calculation unit 15 calculates the difference between the target aberration signal from the target wavefront calculation unit 12 and the electric signal related to the wavefront of the light beam from the wavefront calculation unit 14, and calculates the wavefront modulation unit calculated from the information 21 control signals are output.
  • Step S15 When the received light intensity information signal is equal to or greater than the threshold value (when Step S15 is Yes), that is, when the light beam coupling efficiency is equal to or greater than the threshold value, the control unit 11 resumes or restores the light amplification. That is, an optical amplification control signal for recovering the emission of the excitation light is output to the excitation light source 34 (step S16). Thereafter, optical space communication is resumed.
  • the wavefront modulation unit 21 adds aberration to the light beam and disturbs the wavefront, thereby shifting to the optical fiber 32. This reduces the coupling efficiency of the light beam. At the same time, the emission of the excitation light to the excitation light source 34 is stopped or reduced. Further, after improving the distorted wavefront by the wavefront modulation unit 21 stepwise until the received light intensity information signal becomes equal to or greater than the threshold value, the emission of the excitation light to the excitation light source 34 is resumed.
  • This operation is realized by a component for wavefront compensation that performs wavefront compensation of a light beam caused by atmospheric fluctuations and a component for optical amplification that improves the light receiving sensitivity. Therefore, while improving the light receiving sensitivity during optical space communication, it is possible to suppress the addition of components for suppressing optical surges, the increase in man-hours for assembly work accompanying the addition, and the addition of control steps for the added components it can.
  • the light beam incident on the wavefront modulation unit 21 is momentarily interrupted, it is possible to prevent the excitation light from being accumulated in the optical fiber amplifier 33 and the energy from being output to the light receiving unit 35 as an optical surge. Further, when the wave front disturbance of the light beam is recovered, the light beam focused on the optical fiber 32 is efficiently incident and the emission of the excitation light from the excitation light source 34 is resumed, so that the light receiving sensitivity during optical communication is reduced. None do.
  • the spherical aberration is gradually improved and the light amplification control signal to be restarted after the received light intensity information signal becomes equal to or higher than the threshold value is output to the excitation light source 34.
  • the present invention is not limited to this.
  • an optical amplification control signal for gradually improving the spherical aberration and gradually amplifying the excitation light may be output to the excitation light source 34.
  • FIG. 7 is a block diagram showing the configuration of the light control apparatus 3 according to the third embodiment of the present invention.
  • the light control device 3 of the third embodiment has a configuration in which a protection time timer 16 is added to the light control device 2 of the second embodiment, and the control unit 11 of the third embodiment is the second embodiment. A function is added to the control unit 11.
  • Other components are the same as those of the light control device 2 of the second embodiment, and a description thereof will be omitted.
  • control unit 11 outputs a target aberration signal and an optical amplification control signal based on the received light intensity information signal from light intensity calculation unit 10.
  • a start signal including protection time start information is output to the protection time timer 16
  • an end signal including protection time end information is input from the protection time timer 16.
  • the protection time is the time from the time when the amplification of light by the excitation light source 34 is stopped or reduced by the optical amplification control signal to the time when the energy of the excitation light accumulated in the optical fiber amplifier 33 is spontaneously emitted.
  • the increased target wavefront aberration is maintained and is not reduced stepwise.
  • the protection time timer 16 receives an activation signal from the control unit 11 and activates the timer according to the signal. After reaching the predetermined protection time after the timer is started, an end signal including information on the end of the protection time is output.
  • FIG. 8 is a flowchart for explaining the operation of the light control device 3. Further, in the flowchart of the light control device 3 of the third embodiment, a protection time timer activation and completion flow are added to the flowchart of the light control device 2 of the second embodiment. The other flow is the same as the flow of the light control device 3 of the second embodiment, and a description thereof will be omitted.
  • the target aberration signal is a signal set based on spherical aberration.
  • control part 11 implements the flow from step S11 to step S13 during optical space communication. Then, the control part 11 outputs the starting signal containing the start information of protection time to the protection time timer 16 (step S20). Next, the control unit 11 monitors whether or not an end signal including end information of the protection time is input (step 21). If there is no input of the end signal (No in step 21), the monitoring of the input of the end signal is continued. On the other hand, when there is an input of an end signal (when step 21 is Yes), the process proceeds to the next step. Thereafter, the flow from step S14 to step S16 is executed.
  • the protection time timer 16 by providing the protection time timer 16, the energy accumulated in the optical fiber amplifier 33 is spontaneously released while suppressing the input of excitation light during the protection time. be able to. For this reason, generation
  • the value of the target aberration signal is changed in a stepwise manner (spherical aberration is reduced in a stepwise manner). It is not limited to.
  • the target aberration signal may be changed from a large value to a small value at a time.
  • the small value of the target aberration signal may be a value before it falls below the threshold value of the received light intensity information signal.
  • FIG. 9 is a block diagram showing the configuration of the light control device 4 according to the fourth embodiment of the present invention.
  • the light control device 4 of the fourth embodiment has a configuration in which a wavefront storage unit 17 is added to the light control device 2 of the second embodiment, and the control unit 11 of the fourth embodiment is the second embodiment. A function is added to the control unit 11.
  • Other components are the same as those of the light control device 2 of the second embodiment, and a description thereof will be omitted.
  • the wavefront recording unit 17 stores the light intensity signal detected by the light receiving unit 35 and the wavefront information calculated by the wavefront calculating unit 14 as the wavefront at the moment when the light intensity signal is reduced. . Specifically, when the light intensity information signal of the wavefront sensor 23 decreases, that is, when the coupling efficiency of the light beam to the optical fiber 32 is low, for each value of the light intensity signal that increases or decreases, The value and the corresponding wavefront information are stored. The stored wavefront information is output to the control unit 11 as target wavefront information.
  • the wavefront when the received light intensity information signal of the wavefront sensor 23 is lowered is the wavefront information calculated by the wavefront calculator 14 when the coupling efficiency of the light beam to the optical fiber 32 is low, is the wavefront during optical space communication.
  • store while performing the wavefront compensation of a light beam using the calculating part 14.
  • the present invention is not limited to this.
  • information on the wavefront calculated by the wavefront calculating unit 14 may be stored.
  • the control unit 11 inputs the received light intensity information signal from the light intensity calculation unit 10 and the wavefront information from the wavefront storage unit 17.
  • the wavefront information input from the wavefront storage unit 17 is used as the target aberration signal.
  • an optical amplification control signal for stopping the amplification of light is output to the optical amplification unit 30.
  • step S12 and step S14 of the light control method of the light control apparatus 2 the wavefront information input from the wavefront storage unit 17 is used as a target aberration signal for improving or improving the spherical aberration.
  • the other flow is the same as the light control method using the light control device 2.
  • the wavefront when the light reception intensity information signal of the wavefront sensor 23 is lowered based on the light intensity signal detected by the light receiving unit 35 affected by the light surge that is, Wavefront information when the coupling efficiency of the light beam to the optical fiber 32 is low can be set as the target aberration.
  • the influence by an optical surge can be suppressed further.
  • an acquisition tracking unit may be provided in the preceding stage of the wavefront modulation unit 21. That is, the light beam captured and tracked by the capture and tracking unit is incident on the wavefront modulation unit 21.
  • the capture tracking unit includes, for example, a gimbal mirror, a steering mirror, an area sensor, a quadrant sensor, and the like.
  • the gimbal mirror roughly controls the directivity direction of the space optical communication device equipped with the light control device described in the second to third embodiments in a wide area.
  • the steering mirror controls the pointing direction of the optical space communication device with high accuracy in a narrow area.
  • the area sensor roughly detects the directivity direction of the space optical communication apparatus in a wide area from the incident light beam.
  • the quadrant sensor detects the directivity direction of the optical space communication device from the incident light beam with high accuracy in a narrow area.
  • FIG. 10 is a block diagram showing the configuration of the light control device 5 and the optical space communication device according to the fifth embodiment of the present invention.
  • the light control device 5 of the fifth embodiment has the same configuration as the light control device 2 of the second embodiment, and the optical space communication device of the fifth embodiment is the light control device 2 of the second embodiment.
  • a capture tracking unit 24 is added.
  • the control unit 11 and the light intensity calculation unit 18 of the fifth embodiment are different from the control unit 11 and the light intensity calculation unit 10 of the second embodiment.
  • Other components are the same as those of the light control device 2 of the second embodiment, and a description thereof will be omitted.
  • the capture tracking unit 24 has the above-described configuration and function. Further, the light beam incident on the capture tracking unit 24 is detected by an area sensor or a four-divided sensor. An electrical signal having information on the detected light intensity distribution is output to the light intensity calculation unit 18.
  • the light intensity calculation unit 18 receives an electrical signal from the capture tracking unit 24, calculates the received light intensity, and outputs a received light intensity information signal including the information to the control unit 11.
  • the wavefront sensor 23 of the fifth embodiment includes information on the phase or the gradient of the phase of a plurality of regions in a two-dimensional plane that intersects the traveling direction of the light beam (the direction of incidence on the wavefront sensor 23). Only the electrical signal is output to the wavefront computing unit 14.
  • the received light intensity is calculated based on the information of the light intensity distribution acquired by the light receiving sensor (for example, the area sensor or the four-divided sensor) of the acquisition and tracking unit having a spatial resolution lower than that of the wavefront sensor 23 using the CCD element or the CMOS element. Calculate. Therefore, the calculation amount of the light intensity calculation unit can be reduced from the second embodiment to the fourth embodiment.
  • the light receiving sensor for example, the area sensor or the four-divided sensor
  • step S3 after the control unit 11 outputs an optical amplification control signal for stopping or reducing the amplification of light (step S3 in the first embodiment, in step S13 of the second to fourth embodiments, the control signal 11 outputs a target aberration signal for improving wavefront aberration (or spherical aberration) (steps S4 and second of the first embodiment).
  • step S14 the control unit 11 may insert a step of monitoring whether the received light intensity information signal is equal to or less than a threshold value.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • General Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • Optics & Photonics (AREA)
  • Optical Communication System (AREA)
  • Lasers (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

Selon l'invention, des coûts augmentent et une commande devient compliquée lorsque l'on essaie d'éviter les effets d'augmentations subites de lumière, et par conséquent le dispositif de commande de lumière selon l'invention comprend : un moyen de modulation de front d'onde qui commande le front d'onde d'une lumière incidente ; un moyen de détection qui obtient des informations d'intensité de lumière incidente ; un moyen de commande qui détermine un front d'onde sur la base des informations d'intensité ; et un moyen de commande de front d'onde qui commande le moyen de modulation de front d'onde de telle sorte que le front d'onde de lumière incidente devient sensiblement égal au front d'onde cible.
PCT/JP2014/001493 2013-03-19 2014-03-17 Dispositif de commande de lumière, dispositif de communication de lumière spatiale l'utilisant, et procédé de commande de lumière WO2014148027A1 (fr)

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JP2016119673A (ja) * 2014-12-23 2016-06-30 テザト−スペースコム・ゲーエムベーハー・ウント・コー・カーゲー 衛星通信リンク
JPWO2021100129A1 (fr) * 2019-11-19 2021-05-27
CN117477331A (zh) * 2023-03-28 2024-01-30 齐鲁中科光物理与工程技术研究院 一种微增益叠程放大装置及相位补偿、模式匹配方法

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JP2001036471A (ja) * 1999-07-15 2001-02-09 Mitsubishi Electric Corp 波面誤差検出装置及び波面誤差検出方法
JP2006094135A (ja) * 2004-09-24 2006-04-06 Olympus Corp 空間光通信装置
JP2006094465A (ja) * 2004-08-24 2006-04-06 Hamamatsu Photonics Kk 光無線通信装置
JP2007506984A (ja) * 2002-10-17 2007-03-22 エイオプティクス テクノロジーズ，インク． 適応光学を用いた自由空間光学通信システム用の複合波面センサおよびデータ検出器

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JP2001036471A (ja) * 1999-07-15 2001-02-09 Mitsubishi Electric Corp 波面誤差検出装置及び波面誤差検出方法
JP2007506984A (ja) * 2002-10-17 2007-03-22 エイオプティクス テクノロジーズ，インク． 適応光学を用いた自由空間光学通信システム用の複合波面センサおよびデータ検出器
JP2006094465A (ja) * 2004-08-24 2006-04-06 Hamamatsu Photonics Kk 光無線通信装置
JP2006094135A (ja) * 2004-09-24 2006-04-06 Olympus Corp 空間光通信装置

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016119673A (ja) * 2014-12-23 2016-06-30 テザト−スペースコム・ゲーエムベーハー・ウント・コー・カーゲー 衛星通信リンク
JPWO2021100129A1 (fr) * 2019-11-19 2021-05-27
WO2021100129A1 (fr) * 2019-11-19 2021-05-27 日本電信電話株式会社 Récepteur, émetteur-récepteur, système de transmission de fréquences optiques spatiales et procédé de transmission de fréquences optiques spatiales
JP7231059B2 (ja) 2019-11-19 2023-03-01 日本電信電話株式会社 受信機、送受信機、空間光周波数伝送システム及び空間光周波数伝送方法
CN117477331A (zh) * 2023-03-28 2024-01-30 齐鲁中科光物理与工程技术研究院 一种微增益叠程放大装置及相位补偿、模式匹配方法
CN117477331B (zh) * 2023-03-28 2024-05-14 齐鲁中科光物理与工程技术研究院 一种微增益叠程放大装置及相位补偿、模式匹配方法

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