WO2016187826A1 - Optical receiver and optical receiver-based optical signal adjustment method - Google Patents
Optical receiver and optical receiver-based optical signal adjustment method Download PDFInfo
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- WO2016187826A1 WO2016187826A1 PCT/CN2015/079857 CN2015079857W WO2016187826A1 WO 2016187826 A1 WO2016187826 A1 WO 2016187826A1 CN 2015079857 W CN2015079857 W CN 2015079857W WO 2016187826 A1 WO2016187826 A1 WO 2016187826A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
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- Embodiments of the present invention relate to the field of free optical communications, and in particular, to an optical receiver and an optical signal adjusting method based on an optical receiver.
- OWC Optical Wireless Communication
- OWC Optical Wireless Communication
- OWC uses a free-space channel for optical signal transmission.
- OWC is widely used due to its flexible installation, anti-electromagnetic radiation, and no need for frequency band applications.
- the optical signal is transmitted in the atmospheric channel, it is affected by atmospheric turbulence, which causes the refractive index of the local atmosphere to change randomly, causing wavefront distortion of the optical signal. As the transmission distance increases, this distortion becomes more and more serious.
- the wavefront-distorted beams cannot converge to a point, forming a diffuse spot with a randomly varying diameter. This effect is also known as optical scintillation.
- the receiving antenna has a limited area and cannot receive the entire spot, resulting in random loss of the optical signal.
- the optical current after the conversion of the optical signal of the receiving antenna fluctuates significantly, and the frequency of the fluctuation is less than 10 kHz. This fluctuation causes the error rate of the optical receiver to be greatly increased.
- an adaptive optics technique is proposed to correct the wavefront of the optical signal, so that the beam reconverges to a point, eliminates optical flicker, compensates for optical signal degradation caused by atmospheric turbulence, and reduces the error of the optical receiver.
- Code rate The current optical receiver works on the principle that the receiving antenna is composed of a deformable curved mirror and a secondary mirror, and a part of the light beam is concentrated into the receiving optical fiber.
- the optical signal is ultimately converted into an electrical signal by a photodetector.
- the communication receiver demodulates, recovers, and then sends the electrical signal to the destination network.
- the other part of the beam is reflected by the beam splitter into the wavefront sensor.
- the steering angle of each small mirror of the surface deforming mirror is controlled by voltage.
- the control unit applies different voltages to the electrodes to adjust the surface shape of the deformable mirror in time, thereby dynamically correcting the wavefront distortion of the beam, so that the beam can be Accurately converge to the input end of the receiving fiber.
- the current optical signal adaptive adjustment method has the following problems: the manufacturing process of the curved mirror is complicated and the cost is high; the curved mirror uses the piezoelectric effect to adjust the phase, and has the problems of large power consumption and slow adjustment speed; In the process of phase adjustment, each small mirror in the mirror is required to be deformed in the surface. Adjustments are made and the calculation cost is large.
- the technical problem to be solved by the embodiments of the present invention is to provide an optical receiver and an optical signal adjustment method based on optical reception, which can solve the problems of high cost, large power consumption, and slow adjustment speed in the prior art.
- a first aspect of an embodiment of the present invention provides an optical receiver, including: an optical antenna, a beam splitter, a charge coupled device CCD, a photodetector, a driver, an optical phased array OPA, and a low pass filter. And a processor; wherein the OPA comprises a grating array, a phase modulator array, and an optocoupler;
- the optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal
- the beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;
- the CCD is configured to collect a spot of the first optical signal
- the OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
- the photodetector is configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal
- the low pass filter is configured to perform low pass filtering processing on the electrical signal to generate a low frequency noise electrical signal
- the processor is configured to perform sampling processing on the low frequency noise electrical signal to obtain at least one sample value, and calculate a variance of the at least one sample value;
- variance is greater than a variance threshold, determining a phase modulator to be adjusted according to the position information of the spot, and calculating a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm;
- the processor sends a phase adjustment indication message to the driver, the phase modulation indication message for instructing the driver to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
- the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
- the mapping relationship of the devices determines the phase modulator to be adjusted associated with the at least one grating.
- the grating array is located in front of a focal plane of the optical antenna, and a minimum diameter of the grating array For D OPA , the minimum diameter of the CCD is D CCD , then
- F 0 is the focal length of the optical antenna
- ⁇ L is the distance between the grating array and the focal plane of the optical antenna
- ⁇ is the maximum deflection between the concentrated optical signal and the optical axis Angle
- D r is the diameter of the optical antenna.
- the method further includes: an amplifier connected to the photodetector and the low pass filter
- the transimpedance amplifier is configured to perform amplification processing on the electrical signal generated by the photodetector, and transmit the amplified electrical signal to the low pass filter.
- the calculating, by the optical adaptive algorithm, the voltage adjustment amount of the phase modulator to be adjusted includes:
- the voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
- a second aspect of the embodiments of the present invention provides an optical signal adjustment method based on an optical receiver, where the optical receiver includes: an optical antenna, a beam splitter, a charge coupled device CCD, and an optical phased array OPA; wherein the OPA Including a grating array, a phase modulator array, and an optocoupler;
- the optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal
- the beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;
- the CCD is configured to collect a spot of the first optical signal
- the OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
- the optical signal adjustment method includes:
- variance is greater than a variance threshold, determining a phase modulator to be adjusted according to the position information of the spot, and calculating a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm;
- the carrying voltage of the phase modulator to be adjusted is adjusted according to the voltage regulation amount.
- the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
- the method before performing the low-pass filtering processing on the electrical signal to generate the low-frequency noise electrical signal, the method further includes:
- the electrical signal is amplified.
- the calculating, by the optical adaptive algorithm, the voltage adjustment amount of the phase modulator to be adjusted includes:
- the voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
- a third aspect of the embodiments of the present invention provides an optical receiver, including: an optical antenna, a beam splitter, a charge coupled device CCD, an optical phased array OPA, a photoelectric conversion module, a low pass filter module, a variance calculation module, and a phase control parameter.
- the optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal
- the beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;
- the CCD is configured to collect a spot of the first optical signal
- the OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
- a photoelectric conversion module configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal
- a low pass filtering module configured to perform low pass filtering on the electrical signal to generate a low frequency noise electrical signal
- a variance calculation module configured to perform sampling processing on the low-frequency noise electrical signal to obtain at least one sampled value, and calculate a variance of the at least one sampled value
- phase control parameter generating module configured to determine a phase modulator to be adjusted according to position information of the spot if the variance is greater than a variance threshold, and calculate a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm ;
- a voltage adjustment module configured to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
- the phase control parameter generating module includes:
- a calculating unit configured to calculate a pixel distribution area of the spot on the CCD
- a query unit configured to query at least one grating associated with the pixel distribution area, and determine the phase modulator to be adjusted associated with the at least one grating according to a mapping relationship between the grating and the phase modulator.
- the optical antenna, the optical splitter, and the grating array of the OPA share an optical axis, the optical splitter and the optical axis At an angle of 45°, the distance from the focal plane of the optical antenna to the center point of the beam splitter is L1, and the line connecting the center point of the CCD to the center point of the beam splitter is perpendicular to the optical axis.
- the grating array is located in front of a focal plane of the optical antenna, and the minimum diameter of the grating array is D OPA
- the minimum diameter of the CCD is D CCD
- F 0 is the focal length of the optical antenna
- ⁇ L is the distance between the grating array and the focal plane of the optical antenna
- ⁇ is the maximum deflection between the concentrated optical signal and the optical axis Angle
- D r is the diameter of the optical antenna.
- the method further includes:
- an amplification module configured to perform amplification processing on the electrical signal generated by the photoelectric conversion module, and send the amplified electrical signal to the low-pass filter module.
- the phase control parameter generating module is configured to calculate the phase control to be adjusted according to a random parallel gradient algorithm The voltage adjustment amount of the device; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
- Optical antenna and OPA are used to receive free-space optical signals, and OPA-based electro-optical phase modulation effects and optical adaptive algorithms are used to eliminate the effects of atmospheric turbulence noise, compared to prior art variability-based curved mirrors and piezoelectric effects.
- Spatial phase modulation has the advantages of simple processing, low power consumption and high adjustment speed. At the same time, only the phase modulator corresponding to the grating illuminated by the optical signal needs to be adjusted, the adjustment range is more accurate, and the calculation amount is small.
- FIG. 1 is a schematic structural diagram of an optical receiver according to an embodiment of the present invention.
- FIG. 2 is a schematic structural diagram of an OPA according to an embodiment of the present invention.
- Figure 3 is a schematic structural view of the grating of Figure 2;
- Figure 4a is a graph showing the amplitude variation of the electrical signal of Figure 1;
- Figure 4b is a graph showing the amplitude variation of the level noise electrical signal of Figure 1;
- FIG. 5 is a schematic structural diagram of an optical path of an optical receiver according to an embodiment of the present invention.
- FIG. 6 is a schematic structural diagram of another optical path of an optical receiver according to an embodiment of the present invention.
- FIG. 7 is a schematic flowchart diagram of an optical signal adjustment method based on an optical receiver according to an embodiment of the present invention.
- FIG. 8 is another schematic structural diagram of an optical receiver according to an embodiment of the present invention.
- an optical lens is a receiving lens 10
- a receiving lens is a convex lens, such as a Fresnel lens.
- the optical receiver includes: a receiving lens 10, a beam splitter 11, a photodetector 12, an OPA 13, a driver 14, a low pass filter 15, a processor 16, and a CCD (Charge Coupled Device, CCD for short) 17, OPA (Optical Phased Array, OPA for short) 13 includes a grating array, a phase modulator array, and an optical coupler.
- the number of gratings in the phase grating array in OPA13 is equal to the number of phase modulators in the phase modulator array.
- the phase modulator has a one-to-one correspondence.
- FIG. 2 is a schematic structural diagram of an OPA according to an embodiment of the present invention.
- the OPA includes a grating array, a phase modulator array, and an optical coupler.
- the grating, the phase modulator, and the optical coupler are connected by a waveguide.
- FIG. 3 is a schematic structural view of a grating in FIG. 2, the grating is composed of a silicon dioxide substrate, a silicon grating and a silicon waveguide, and the optical signal is irradiated on the silicon grating, and the silicon grating converts the optical signal into a waveguide light wave, and transmits the light through the silicon waveguide. To the input port of the optocoupler.
- the optical signal When the optical signal is vertically or obliquely irradiated on the grating array, the optical signal forms a spot on the grating array, and a part of the grating in the grating array receives the optical signal, and the grating irradiated by the optical signal couples the surface light wave into the single-mode waveguide. Converted to waveguide light waves, respectively.
- the number of gratings in the grating array is M, M ⁇ 2. In practical applications, the value of M is generally very large, and when the optical signal is obliquely irradiated to the optical antenna at a certain angle, the optical signal output from the optical antenna is not It will exceed the edge of the raster array so that it captures as much light as possible.
- Each grating is connected to a phase modulator, and the output port of the phase modulator is connected to the input port of the optical coupler.
- the phase changes of the waveguide light waves passing through each of the grating and phase modulators to the optical coupler are equal, that is, the optical path difference between the input ports of each of the grating-phase modulator-optical couplers is equal.
- the phase modulator can modulate the phase of the waveguide light wave by electro-optical effect or current injection effect, and has high-speed phase adjustment capability.
- the specific phase modulation method can be realized by the driver changing the carrying voltage of the corresponding phase modulator, and the modulation process of the phase of the waveguide light wave by the phase modulator is linear within a certain voltage range.
- the optical coupler can be a planar lens coupler, and the optical coupler is a multi-port input single-port input device. If the number of gratings is too large, a large number of vertical optical couplers can be connected by optical coupler cascading, light The output port of the coupler outputs a combined optical signal, and the combined optical signal is directly sent to the photodetector 12 or sent to the photodetector 12 via the pigtail.
- OPA can be fabricated on a flat silicon substrate by a micro-nano fabrication process.
- a high refractive index low loss optical material such as silicon nitride or indium phosphorus can be used for the production of the OPA in the embodiment of the present invention.
- the optical transmitter (not shown) modulates the digital information onto the coherent optical carrier by the electro-optic modulator to generate an optical signal.
- the process of the electro-optic modulation may be internal modulation or external modulation.
- the invention does not limit the optical signal to the transmitting lens.
- the optical signal When transmitting, the optical signal will be affected by atmospheric turbulence during the free space transmission, resulting in distortion of the wavefront phase of the optical signal.
- the optical signal reaches the optical antenna of the optical receiver, the optical signal of the wavefront phase distortion cannot be generated.
- the optical antenna 10 is configured to converge the received optical signal to generate a concentrated optical signal.
- the optical signal transmitted by the optical transmitter is affected by atmospheric turbulence, which may cause a diffusion effect, and the optical antenna 10 will be free.
- the optical signal transmitted from the space is subjected to convergence processing, and the convergence optical signal is generated by the convergence of the smaller optical signal.
- the optical splitter 11 is configured to perform the spectral processing on the concentrated optical signal generated by the optical antenna 10, and generate the first after the optical processing.
- the optical signal and the second optical signal have the same optical characteristics of the first optical signal and the second optical signal, and the CCD 17 is configured to image the first optical signal to generate a spot of the first optical signal; the second optical signal is irradiated on the OPA13.
- On the grating array at least one waveguide light wave passing through the grating array and the phase modulator array is superimposed on the optical coupler to generate a combined optical signal.
- the grating signal can detect the optical signal by the partial grating, and the grating illuminated by the optical signal couples the detected optical signal into the waveguide optical wave, and the waveguide optical wave is input to the corresponding phase modulator.
- the optical coupler is coupled; the grating without the illumination of the optical signal does not generate the waveguide light wave; at this time, the phase modulator does not perform the phase modulation operation on the waveguide light wave.
- the photodetector 12 is configured to perform photoelectric conversion processing on the combined optical signal outputted by the OPA 13, and generate an electrical signal after the photoelectric conversion processing; the low-pass filter is configured to perform low-pass filtering processing on the electrical signal to generate a low-frequency noise electrical signal.
- the frequency of the optical signal is very high (in GHz).
- the frequency of atmospheric turbulence noise is much lower than the frequency of the optical signal, and its frequency is generally less than 10 kHz. Therefore, atmospheric turbulence noise is a slow envelope noise applied on the basis of the optical signal.
- the amplitude of the electrical signal changes little in a short time, as shown by the dashed box in Fig. 4a.
- the low-pass filter filters out the high-frequency portion of the electrical signal i 0 to obtain the low-frequency noise electrical signal i 1 (as shown in Figure 4b), and the amplitude variation of the low-frequency noise electrical signal i 1 reflects the magnitude of the atmospheric turbulent noise.
- the processor 16 is configured to perform sampling processing on the low-frequency noise electrical signal output by the low-pass filter.
- the specific process may be: acquiring at least one sampling value according to a preset sampling period (for example, the number of sampling values is greater than 10), for at least one
- the sampled value calculates its variance. If the calculated variance is greater than the variance threshold, the influence of atmospheric turbulence noise is not negligible.
- the processor 16 determines the phase modulator to be adjusted according to the position information of the spot collected by the CCD 17, for example, each phase modulator.
- a unique identifier is provided, and the phase modulator to be adjusted is represented by a unique identifier; the phase modulator to be adjusted is a phase modulator corresponding to a partial grating illuminated by the second optical signal, and the processor 16 is configured according to a preset adaptive algorithm.
- the adjusted phase modulator generates a voltage adjustment amount, the voltage adjustment amount is divided into a positive voltage adjustment amount and a negative voltage adjustment amount, the positive voltage adjustment amount is used to increase the load voltage on the phase modulator, and the negative voltage adjustment amount is used to reduce the phase modulation Carrying voltage on the device.
- the processor 16 transmits a phase modulation indication message to the driver 14, the phase adjustment indication message for instructing the driver to adjust the carrier voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
- the phase adjustment indication message may carry an identifier of the phase modulator to be adjusted and a voltage adjustment amount of the phase modulator to be adjusted.
- the phase modulators in the phase modulator array are arranged in order, and the phase modulator to be adjusted is represented by a bitmap, for example, the identifier of the phase modulator to be adjusted carried in the phase adjustment indication message is represented as :Address (1,0,1,1,...,1,1), where 1 denotes a phase modulator requiring phase adjustment, 0 denotes a phase modulator that does not require phase adjustment, and the phase modulation indicates a voltage carried in the message
- the adjustment amount is expressed as: Voltage (U1, U2, ..., Un), U1 represents the voltage adjustment amount on the first phase modulator, Un represents the voltage adjustment amount of the nth phase modulator, and Un can use positive and negative values.
- the driver 14 determines a phase modulator that needs to be adjusted according to the address, and adjusts a load voltage of the phase modulator according to the voltage adjustment amount, so that the change is to be adjusted.
- the phase of the waveguide light wave of the phase modulator is such that the phase of the waveguide light wave input by the optical coupler is the same. Even if the waveguide light wave input by the optical coupler has coherence, the optical coupler performs coherent superposition processing on the waveguide light wave of the same phase. Combine optical signals.
- the processor 13 may be a dedicated integrated circuit, or a general-purpose integrated circuit, such as a DSP or an FPGA, and the invention is not limited thereto.
- the combined optical signal of the phase adjustment of the photodetector 12 is converted into an electrical signal
- the low pass filter 15 samples the electrical signal to obtain at least one sampled value
- the processor 16 calculates the variance of at least one sampled value.
- the calculated variance is still greater than the variance threshold and continues to instruct the driver 14 to perform a phase adjustment operation on the phase modulator of the OPA until the calculated variance is less than the variance threshold.
- the optical antenna can also be a reflective antenna, and the reflective antenna is configured to converge and reflect the optical signal in the free space to generate a concentrated optical signal, and transmit the optical signal to the optical splitter for splitting to generate the first optical signal and the second optical signal.
- the CCD receives the first optical signal
- the OPA receives the second optical signal.
- the working principle of the circuit portion is the same as that in FIG. 1.
- the structure of the reflective antenna can be referred to the description in the prior art, and details are not described herein again.
- the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
- the CCD includes a plurality of closely arranged pixels, and the pixels on the CCD are pre-divided into a plurality of grids, each of which corresponds to a grating on the grating array, and the number of the grids is equal to the number of gratings in the grating array, first A spot is formed on the CCD illuminated by the light signal, and the shape of the spot is generally close to a circle.
- the processor 16 searches for the pixel distribution area according to the pixel distribution area of the spot on the CCD. Grid, according to the mapping relationship between the grid and the grating, the corresponding grating of the second optical signal on the OPA is determined.
- each grating in the OPA corresponds to a phase modulator, thereby
- the phase modulator to be adjusted is determined, and the phase modulator to be adjusted can be identified by means of a bitmap or an identification.
- the optical splitter and the grating array of the OPA share an optical axis
- the optical antenna, the optical splitter and the grating array of the OPA share an optical axis
- the optical splitter forms an angle of 45° with the optical axis.
- a distance from a focal plane of the optical antenna to a center point of the beam splitter is L1
- a line from a center point of the CCD to a center point of the beam splitter being perpendicular to the optical axis
- the common optical axis of the optical antenna, the optical splitter, and the OPA grating array indicates that the optical axis passes through the center point of the optical antenna, the center point of the optical splitter, and the center point of the grating array, and the optical axis is perpendicular to the focal plane of the optical antenna and the grating
- the array is vertical; the beam splitter is at an angle of 45° to the optical axis, such that the splitter can split the incident concentrated optical signal into a second optical signal parallel to the concentrated optical signal and a first optical signal perpendicular to the concentrated optical signal.
- the geometric relationship is convenient for calculating and adjusting the position of the optical component in the optical receiver; the distance from the focal plane of the optical antenna to the center point of the optical splitter is L1, and the line connecting the center point of the CCD to the center point of the optical splitter is perpendicular to the optical axis, CCD
- the first light signal is irradiated to the spot formed by the CCD.
- the smallest size can reduce the size of the CCD and reduce the cost.
- the optical receiver further includes an amplifier 18 connected between the photodetector 12 and the low pass filter 15 for amplifying the electrical signal generated by the photodetector 12, The amplified electrical signal is sent to the low pass filter 15.
- the amplifier 18 can be a transconductance amplifier.
- the optical receiver further includes: an amplifier connected between the photodetector and the low pass filter, the amplifier being used to generate the electricity generated by the photodetector The signal is amplified, and the amplified electrical signal is sent to the low pass filter.
- the photodetector 12 can be a photoelectric avalanche diode, and the amplifier can be a transconductance amplifier.
- the calculating, according to an algorithm optical adaptive algorithm, the power of the phase modulator to be adjusted includes:
- the voltage adjustment amount of the phase modulator to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase modulator in the phase modulator to be adjusted conforms to a Bernoulli distribution.
- the voltage adjustment amount refers to the amount of increase or decrease of the load voltage on the phase modulator, and is provided with N phase modulators to be adjusted, and the voltage adjustment amount of each phase controller is Voltage ( ⁇ U1, ⁇ U2, ⁇ U3, ..., ⁇ Un), the respective voltage adjustment amounts in the Voltage are in accordance with the Bernoulli distribution.
- the random parallel gradient algorithm can be that the phase of the waveguide light wave passing through the N phase controllers to be adjusted tends to be uniform, that is, the N-channel waveguide light wave has coherence, and the optical coupler can perform coherent superposition processing with good convergence.
- the grating array is located in front of a focal plane of the optical antenna, the minimum diameter of the grating array is D OPA , and the minimum diameter of the CCD is D CCD , then
- F 0 is the focal length of the optical antenna
- ⁇ L is the distance between the grating array and the focal plane of the optical antenna
- ⁇ is the maximum deflection between the concentrated optical signal and the optical axis Angle
- D r is the diameter of the optical antenna.
- the structure of the optical path of the embodiment of the present invention is described with reference to FIG. 5 and FIG. 6.
- the diameter of the optical antenna is D r
- the focal length of the optical antenna is F 0
- the grating array of the OPA is The optical axis of the optical antenna is perpendicular, and the optical axis of the optical antenna passes through the center point of the grating array
- the optical splitter is located between the optical antenna and the grating array, the optical splitter is at an angle of 45° with the optical axis, and the optical axis of the optical antenna passes through the optical splitter The center point.
- the CCD is located on the equivalent focal plane of the optical antenna.
- the specific position is that the line connecting the center point of the CCD and the center point of the beam splitter is perpendicular to the optical axis, and the distance of the line is equal to the distance from the center point of the beam splitter to the focal plane.
- the distance between the grating array and the focal plane of the optical antenna is ⁇ L, and the magnitude of ⁇ L depends on the number M of gratings in the grating array.
- the area of each grating in the grating array is S 0 , M is large enough to ensure that the beam is vertical Under the action of illumination or oblique illumination, as well as atmospheric turbulence, the area of the generated spot is smaller than the total area M*S 0 of the grating array.
- the number of gratings can be increased; in order to reduce the complexity of optical adaptive control, the number of gratings can be reduced.
- the maximum deflection angle of the optical signal and the optical axis of the optical receiver is ⁇ .
- the optical signal is obliquely irradiated on the optical antenna, the position of the spot on the CCD is shifted, and the maximum deviation of the spot on the focal plane is
- X shift F 0 * tan ⁇
- the size of the beam splitter is large enough to receive the entire concentrated optical signal emitted by the optical antenna.
- the minimum diameter D OPA of the OPA grating array is determined by the maximum deflection angle of the beam converging optical signal. From the spatial geometric relationship, the calculation formula of D OPA can be expressed as:
- the grating array of the OPA can be prepared by a micro-nano processing method.
- the shape of the grating array of the embodiment is not limited to a circular shape, and may be a rectangle or other shape, and the area of the grating array needs to satisfy a condition larger than ⁇ *D OPA *D OPA /4.
- the shape of the CCD is not limited to a circular shape, and may be a rectangle or other form, and the area of the CCD needs to satisfy a condition larger than ⁇ *D CCD *D CCD /4.
- the optical receiver further includes: a data recovery module 19, configured to perform demodulation processing on the electrical signal input by the amplifier, and obtain digital information loaded in the electrical signal after demodulation processing.
- a data recovery module 19 configured to perform demodulation processing on the electrical signal input by the amplifier, and obtain digital information loaded in the electrical signal after demodulation processing.
- the embodiment of the present invention adopts a compact flat panel OPA, has a simple structure, and has the advantages of simple processing and reliability; the OPA is manufactured by a CMOS process and has the advantages of low power consumption.
- phase adjustment based on electro-optical effect and optical adaptive algorithm, the rate can reach the order of GHz, and has the advantage of high adjustment speed. Only the phase modulator corresponding to the grating illuminated by the optical signal needs to be adjusted, the adjustment range is more accurate, and the calculation amount is small.
- FIG. 7 is a schematic diagram of an optical signal adjustment method based on an optical receiver according to an embodiment of the present invention.
- the method includes:
- the low-pass filter processing may be performed by a low-pass filter, and the low-pass filter performs low-pass filtering processing on the electrical signal to generate a low-frequency noise electrical signal.
- the frequency of the optical signal is very high (in GHz).
- the frequency of atmospheric turbulence noise is much lower than the frequency of the optical signal, and its frequency is generally less than 10 kHz. Therefore, atmospheric turbulence noise is a slow envelope noise applied on the basis of the optical signal.
- the amplitude variation diagram of the electrical signal i 0 input by the photodetector in Fig. 3a the amplitude of the electrical signal changes little in a short time, as shown by the dashed box in Fig. 4a.
- the low-pass filter filters out the high-frequency portion of the electrical signal i 0 to obtain the low-frequency noise electrical signal i 1 (as shown in Figure 4b), and the amplitude variation of the low-frequency noise electrical signal i 1 reflects the magnitude of the atmospheric turbulent noise.
- the optical receiver includes: an optical antenna, a beam splitter, a charge coupled device CCD, and an optical phased array OPA; wherein the OPA includes a grating array, a phase modulator array, and an optical coupler, and the optical antenna can be a receiving lens or a reflection antenna.
- the optical transmitter (not shown) modulates the digital information onto the coherent optical carrier by the electro-optic modulator to generate an optical signal.
- the process of the electro-optic modulation may be internal modulation or external modulation.
- the invention does not limit the optical signal to the transmitting lens.
- the optical signal When transmitting, the optical signal will be affected by atmospheric turbulence during the transmission of free space, causing the wavefront phase of the optical signal to be distorted.
- the optical signal reaches the optical antenna of the optical receiver, the optical signal of the wavefront phase distortion cannot be generated. Converging to a point with correlation, a diffuse spot of randomly varying diameters is formed on the surface of the optical antenna.
- the optical antenna is used to converge the received optical signal to generate a concentrated optical signal.
- the optical signal transmitted by the optical transmitter is affected by atmospheric turbulence, which will cause a diffusion effect, and the optical antenna will be transmitted from free space.
- the incoming optical signal is subjected to convergence processing to generate a concentrated optical signal by focusing on the diameter of the smaller optical signal;
- the optical splitter is configured to perform spectral processing on the concentrated optical signal generated by the optical antenna 10, and generate a first optical signal and a first optical signal after the optical splitting process.
- the optical characteristics of the first optical signal and the second optical signal are exactly the same, the CCD is used to image the first optical signal to generate a spot of the first optical signal, and the second optical signal is irradiated on the grating array of the OPA.
- the grating signal can detect the optical signal by the partial grating, and the grating illuminated by the optical signal couples the detected optical signal into the waveguide optical wave, and the waveguide optical wave is input to the corresponding phase modulator.
- the optical coupler is coupled; the grating without the illumination of the optical signal does not generate the waveguide light wave; at this time, the phase modulator does not perform the phase modulation operation on the waveguide light wave.
- the device acquires at least one sample value according to a preset sampling period (for example, the number of sample values is greater than 10), and calculates a variance of the at least one sample value.
- a preset sampling period for example, the number of sample values is greater than 10
- S705. Determine a phase modulator to be adjusted according to position information of the spot, and calculate a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm.
- the phase modulator to be adjusted is determined according to the position information of the spot collected by the CCD, and the phase modulator to be adjusted, that is, the phase modulator corresponding to the partial grating irradiated by the second light signal, is processed by the processor according to a preset adaptive algorithm.
- the phase modulator to be adjusted generates a voltage adjustment amount, the voltage adjustment amount is divided into a positive voltage adjustment amount and a negative voltage adjustment amount, the positive voltage adjustment amount is used to increase the load voltage on the phase modulator, and the negative voltage adjustment amount is used to reduce the phase The carrying voltage on the modulator.
- the calculated variance is less than the preset variance threshold, it indicates that atmospheric turbulence noise can be ignored and phase control is not required.
- the phase modulators in the phase modulator array are arranged in sequence, and the phase modulator to be adjusted can represent the position in the phase modulator array in a bitmap manner, for example: Address (1, 0, 1, 1, ..., 1,1), 1 indicates a phase modulator that requires phase adjustment, 0 indicates a phase modulator that does not require phase adjustment, Voltage (U1, U2, ..., Un), U1 indicates the first phase modulation
- Address (1, 0, 1, 1, ..., 1,1) 1 indicates a phase modulator that requires phase adjustment
- 0 indicates a phase modulator that does not require phase adjustment
- U1 indicates the first phase modulation
- Un represents the voltage adjustment amount of the nth phase modulator
- Un can use the positive and negative values to indicate the positive voltage adjustment amount and the negative voltage adjustment amount.
- S701 is repeatedly executed to convert the phase-adjusted combined optical signal into an electrical signal, and the electrical signal is sampled to obtain at least one sampled value, and the processor calculates a variance of at least one sampled value, if the calculated The variance is still greater than the variance threshold and continues to the phase modulator of the OPA Perform a phase adjustment operation until the calculated variance is less than the variance threshold and exit the loop.
- the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
- the method before performing the low-pass filtering process on the electrical signal to generate the low-frequency noise electrical signal, the method further includes:
- the electrical signal is amplified.
- calculating the voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm includes:
- the voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
- Embodiments of the present invention perform photoelectric conversion and low-pass filtering processing on an optical signal output by the OPA to obtain a low-frequency noise electrical signal, and calculate a variance of a sampled value of the low-frequency noise electrical signal. If the variance is greater than a variance threshold, the CCD acquires a to-be-adjusted The address of the phase modulator adjusts the load voltage of the phase modulator with adjustment to avoid adjustment of all phase controllers, reducing the amount of calculation.
- FIG. 8 is another schematic structural diagram of an optical receiver according to an embodiment of the present invention.
- the optical receiver includes: an optical antenna 80, a beam splitter 81, a charge coupled component CCD88, and optical
- the optical antenna 80 is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal.
- the beam splitter 81 is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal.
- the CCD 88 is configured to collect a spot of the first optical signal
- the OPA 82 is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
- the photoelectric conversion module 83 is configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal
- a low pass filtering module 84 configured to perform low pass filtering on the electrical signal to generate a low frequency noise electrical signal
- the variance calculation module 85 is configured to perform sampling processing on the low frequency noise electrical signal to obtain at least one sampled value, and calculate a variance of the at least one sampled value;
- the phase control parameter generating module 86 is configured to determine, according to the position information of the spot, a phase modulator to be adjusted, and calculate a voltage adjustment of the phase modulator to be adjusted according to an optical adaptive algorithm, if the variance is greater than a variance threshold the amount;
- the voltage adjustment module 88 is configured to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
- the phase control parameter generating module includes:
- a calculating unit configured to calculate a pixel distribution area of the spot on the CCD
- a query unit configured to query at least one grating associated with the pixel distribution area, and determine the phase modulator to be adjusted associated with the at least one grating according to a mapping relationship between the grating and the phase modulator.
- the optical antenna, the optical splitter and the grating array of the OPA share an optical axis
- the optical splitter is at an angle of 45° to the optical axis
- a focal plane of the optical antenna is to a center of the optical splitter
- the distance of the point is L1
- the line connecting the center point of the CCD to the center point of the beam splitter is perpendicular to the optical axis
- the grating array is located in front of a focal plane of the optical antenna, the minimum diameter of the grating array is D OPA , and the minimum diameter of the CCD is D CCD , then
- F 0 is the focal length of the optical antenna
- ⁇ L is the distance between the grating array and the focal plane of the optical antenna
- ⁇ is the maximum deflection between the concentrated optical signal and the optical axis Angle
- D r is the diameter of the optical antenna.
- the optical receiver further includes: an amplifying module, configured to perform amplification processing on the electrical signal generated by the photoelectric conversion module, and send the amplified electrical signal to the low-pass filtering module.
- an amplifying module configured to perform amplification processing on the electrical signal generated by the photoelectric conversion module, and send the amplified electrical signal to the low-pass filtering module.
- the phase control parameter generating module is configured to calculate a voltage adjustment amount of the phase controller to be adjusted according to a random parallel gradient algorithm; wherein, the voltage adjustment of each phase controller in the phase controller to be adjusted The amount is consistent with the Bernoulli distribution.
- the embodiment of the present invention and the optical signal adjustment method based on the optical receiver are based on the same concept and are used to implement the optical signal adjustment method, and the technical effects thereof are also the same.
- the descriptions of Embodiments 1 and 2 and no longer Narration.
- the storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).
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Abstract
Disclosed is an optical receiver, comprising: an optical antenna, an optical splitter, a charge coupled device (CCD), a photoelectric detector, a driver, an optical phased array (OPA), a low pass filter, and a processor, wherein the OPA comprises a grating array, a phase modulator array, and an optical coupler; the optical antenna, the optical splitter, and the grating array of the OPA share the same optical axis; the optical splitter is located between the optical antenna and the grating array of the OPA; and the grating array is located in front of a focal plane of the optical antenna. Correspondingly, embodiments of the present invention also provide an optical signal adjustment method, and the method has the advantages of being low in cost, low in energy consumption and rapid in adjustment speed.
Description
本发明实施例涉及自由光通信领域,尤其涉及一种光接收机和基于光接收机的光信号调节方法。Embodiments of the present invention relate to the field of free optical communications, and in particular, to an optical receiver and an optical signal adjusting method based on an optical receiver.
OWC(Optical Wireless Communication,简称OWC,光无线通信)利用自由空间信道进行光信号的传输。由于具有安装灵活、抗电磁辐射、无需频段申请等优点,OWC得到广泛应用。光信号在大气信道传输时,受到大气湍流的影响,使得局部大气的折射率发生随机的变化,引起光信号的波前畸变。随着传输距离的增大,这种畸变越来越严重。在接收天线的像平面上,波前畸变的光束无法汇聚到一个点,形成直径随机变化的弥散光斑。这种效应也被称为光学闪烁。接收天线的面积有限,无法接收整个光斑,造成光信号的随机损耗。在时域上,接收天线的光信号转换后的光电流发生显著的波动,波动的频率小于10kHz,这种波动会导致光接收机的误码率大大增加。OWC (Optical Wireless Communication, OWC, Optical Wireless Communication) uses a free-space channel for optical signal transmission. OWC is widely used due to its flexible installation, anti-electromagnetic radiation, and no need for frequency band applications. When the optical signal is transmitted in the atmospheric channel, it is affected by atmospheric turbulence, which causes the refractive index of the local atmosphere to change randomly, causing wavefront distortion of the optical signal. As the transmission distance increases, this distortion becomes more and more serious. On the image plane of the receiving antenna, the wavefront-distorted beams cannot converge to a point, forming a diffuse spot with a randomly varying diameter. This effect is also known as optical scintillation. The receiving antenna has a limited area and cannot receive the entire spot, resulting in random loss of the optical signal. In the time domain, the optical current after the conversion of the optical signal of the receiving antenna fluctuates significantly, and the frequency of the fluctuation is less than 10 kHz. This fluctuation causes the error rate of the optical receiver to be greatly increased.
为了解决这个问题,提出了一种自适应光学的技术,对光信号的波前进行校正,使得光束重新汇聚到一点,消除光学闪烁,补偿大气湍流引起的光信号劣化,降低光接收机的误码率。目前的光接收机的工作原理为:接收天线由可变形曲面镜与次镜构成,将光束的一部分汇聚到接收光纤中。光信号最终被光电探测器转换成电信号。通信接收机对电信号进行解调、恢复,然后送到目的网络。光束的另一部分经分光镜反射到波前传感器中。曲面变形镜的每个小镜子的转向角由电压分别控制。根据波前传感器与接收机总的反馈信息,控制单元分别对各电极施加不同的电压,以对可变形镜的面形进行适时调节,进而对光束的波前畸变进行动态校正,使得光束能被准确地汇聚到接收光纤的输入端面。In order to solve this problem, an adaptive optics technique is proposed to correct the wavefront of the optical signal, so that the beam reconverges to a point, eliminates optical flicker, compensates for optical signal degradation caused by atmospheric turbulence, and reduces the error of the optical receiver. Code rate. The current optical receiver works on the principle that the receiving antenna is composed of a deformable curved mirror and a secondary mirror, and a part of the light beam is concentrated into the receiving optical fiber. The optical signal is ultimately converted into an electrical signal by a photodetector. The communication receiver demodulates, recovers, and then sends the electrical signal to the destination network. The other part of the beam is reflected by the beam splitter into the wavefront sensor. The steering angle of each small mirror of the surface deforming mirror is controlled by voltage. According to the total feedback information of the wavefront sensor and the receiver, the control unit applies different voltages to the electrodes to adjust the surface shape of the deformable mirror in time, thereby dynamically correcting the wavefront distortion of the beam, so that the beam can be Accurately converge to the input end of the receiving fiber.
由此可见,目前的光信号自适应调节方法存在以下问题:曲面反射镜的制作工艺繁杂,成本较高;曲面反射镜利用压电效应来调节相位,具有功耗大和调节速度慢的问题;同时在相位调节的过程中需要对曲面变形镜中每个小镜子
进行调节,计算开销大。It can be seen that the current optical signal adaptive adjustment method has the following problems: the manufacturing process of the curved mirror is complicated and the cost is high; the curved mirror uses the piezoelectric effect to adjust the phase, and has the problems of large power consumption and slow adjustment speed; In the process of phase adjustment, each small mirror in the mirror is required to be deformed in the surface.
Adjustments are made and the calculation cost is large.
发明内容Summary of the invention
本发明实施例所要解决的技术问题在于,提供一种光接收机和基于光接收的光信号调节方法,可解决现有技术中成本高、功耗大和调节速度慢的问题。The technical problem to be solved by the embodiments of the present invention is to provide an optical receiver and an optical signal adjustment method based on optical reception, which can solve the problems of high cost, large power consumption, and slow adjustment speed in the prior art.
为了解决上述技术问题,本发明实施例第一方面提供了一种光接收机,包括:光学天线、分光器、电荷耦合元件CCD、光电探测器、驱动器、光学相控阵列OPA、低通滤波器和处理器;其中,所述OPA包括光栅阵列、相位调制器阵列和光耦合器;In order to solve the above technical problem, a first aspect of an embodiment of the present invention provides an optical receiver, including: an optical antenna, a beam splitter, a charge coupled device CCD, a photodetector, a driver, an optical phased array OPA, and a low pass filter. And a processor; wherein the OPA comprises a grating array, a phase modulator array, and an optocoupler;
所述光学天线用于对接收的光信号进行汇聚处理后生成汇聚光信号;The optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal;
所述分光器用于对所述汇聚光信号进行分路处理后生成第一光信号和第二光信号;The beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;
所述CCD用于采集所述第一光信号的光斑;The CCD is configured to collect a spot of the first optical signal;
所述OPA用于通过所述光栅阵列接收所述第二光信号,并将经由所述光栅阵列和所述相位调制器阵列的波导光波由所述光耦合器处理后生成合路光信号;The OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
所述光电探测器用于对所述合路光信号进行光电转换处理后生成电信号;The photodetector is configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal;
所述低通滤波器用于对所述电信号进行低通滤波处理后生成低频噪声电信号;The low pass filter is configured to perform low pass filtering processing on the electrical signal to generate a low frequency noise electrical signal;
所述处理器用于对所述低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差;The processor is configured to perform sampling processing on the low frequency noise electrical signal to obtain at least one sample value, and calculate a variance of the at least one sample value;
若所述方差大于方差阈值,根据所述光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量;If the variance is greater than a variance threshold, determining a phase modulator to be adjusted according to the position information of the spot, and calculating a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm;
所述处理器向所述驱动器发送相位调节指示消息,所述相位调制指示消息用于指示所述驱动器根据所述电压调节量调节所述待调节的相位调制器的承载电压。The processor sends a phase adjustment indication message to the driver, the phase modulation indication message for instructing the driver to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
结合第一方面,在第一种可能的实现方式中,所述根据所述光斑的位置信息确定待调节的相位调制器包括:With reference to the first aspect, in a first possible implementation, the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
计算出所述光斑在所述CCD上的像素分布区域;Calculating a pixel distribution area of the spot on the CCD;
查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制
器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。Querying at least one grating associated with the pixel distribution region, and according to grating and phase modulation
The mapping relationship of the devices determines the phase modulator to be adjusted associated with the at least one grating.
结合第一方面或第一种可能的实现方式中的任意一种,在第二种可能的实现方式中,所述光学天线、分光器和所述OPA的光栅阵列共光轴,所述分光器与所述光轴成45°角,所述光学天线的焦平面到所述分光器的中心点的距离为L1,所述CCD的中心点到所述分光器的中心点的连线垂直于所述光轴,所述CCD的中心点到所述分光器的中心点的距离为L2,其中,L1=L2。With reference to any one of the first aspect or the first possible implementation manner, in a second possible implementation manner, the optical antenna, the optical splitter, and the grating array of the OPA share an optical axis, and the optical splitter At an angle of 45° to the optical axis, the distance from the focal plane of the optical antenna to the center point of the beam splitter is L1, and the line connecting the center point of the CCD to the center point of the beam splitter is perpendicular to the The optical axis, the distance from the center point of the CCD to the center point of the beam splitter is L2, where L1 = L2.
结合第一方面至第二种可能的实现方式中的任意一种,在第三种可能的实现方式中,所述光栅阵列位于所述光学天线的焦平面的前方,所述光栅阵列的最小直径为DOPA,所述CCD的最小直径为DCCD,则With reference to any one of the first aspect to the second possible implementation, in a third possible implementation, the grating array is located in front of a focal plane of the optical antenna, and a minimum diameter of the grating array For D OPA , the minimum diameter of the CCD is D CCD , then
DOPA=2(F0-△L)*tanθ+(Dr/F0)*△L;D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;
DCCD=2F0*tanθ;D CCD = 2F 0* tan θ;
其中,F0为所述光学天线的焦距,△L为所述光栅阵列与所述光学天线的焦平面之间的距离,θ为所述汇聚光信号与所述光轴的之间的最大偏转角度,Dr为所述光学天线的直径。Wherein F 0 is the focal length of the optical antenna, ΔL is the distance between the grating array and the focal plane of the optical antenna, and θ is the maximum deflection between the concentrated optical signal and the optical axis Angle, D r is the diameter of the optical antenna.
结合第一方面至第三种可能的实现方式中的任意一种,在第四种可能的实现方式中,还包括:放大器,所述放大器连接在所述光电探测器和所述低通滤波器之间,所述跨阻放大器用于对所述光电探测器生成的所述电信号进行放大处理,并将放大处理后的电信号发送至所述低通滤波器。With reference to any one of the first aspect to the third possible implementation, in a fourth possible implementation, the method further includes: an amplifier connected to the photodetector and the low pass filter The transimpedance amplifier is configured to perform amplification processing on the electrical signal generated by the photodetector, and transmit the amplified electrical signal to the low pass filter.
结合第一方面至第四种可能的实现方式中的任意一种,在第五种可能的实现方式中,所述根据光学自适应算法计算所述待调节的相位调制器的电压调节量包括:With reference to any one of the first aspect to the fourth possible implementation, in a fifth possible implementation, the calculating, by the optical adaptive algorithm, the voltage adjustment amount of the phase modulator to be adjusted includes:
根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。The voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
本发明实施例第二方面提供了一种基于光接收机的光信号调节方法,所述光接收机包括:光学天线、分光器、电荷耦合元件CCD、光学相控阵列OPA;其中,所述OPA包括光栅阵列、相位调制器阵列和光耦合器;A second aspect of the embodiments of the present invention provides an optical signal adjustment method based on an optical receiver, where the optical receiver includes: an optical antenna, a beam splitter, a charge coupled device CCD, and an optical phased array OPA; wherein the OPA Including a grating array, a phase modulator array, and an optocoupler;
所述光学天线用于对接收的光信号进行汇聚处理后生成汇聚光信号;The optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal;
所述分光器用于对所述汇聚光信号进行分路处理后生成第一光信号和第二光信号;
The beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;
所述CCD用于采集所述第一光信号的光斑;The CCD is configured to collect a spot of the first optical signal;
所述OPA用于通过所述光栅阵列接收所述第二光信号,并将经由所述光栅阵列和所述相位调制器阵列的波导光波由所述光耦合器处理后生成合路光信号;The OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
所述光信号调节方法包括:The optical signal adjustment method includes:
对所述合路光信号进行光电转换处理后生成电信号;Performing photoelectric conversion processing on the combined optical signal to generate an electrical signal;
对所述电信号进行低通滤波处理后生成低频噪声电信号;Performing low-pass filtering on the electrical signal to generate a low-frequency noise electrical signal;
对所述低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差;Performing sampling processing on the low frequency noise electrical signal to obtain at least one sampled value, and calculating a variance of the at least one sampled value;
若所述方差大于方差阈值,根据所述光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量;If the variance is greater than a variance threshold, determining a phase modulator to be adjusted according to the position information of the spot, and calculating a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm;
根据所述电压调节量调节所述待调节的相位调制器的承载电压。The carrying voltage of the phase modulator to be adjusted is adjusted according to the voltage regulation amount.
结合第二方面,在第一种可能的实现方式中,所述根据所述光斑的位置信息确定待调节的相位调制器包括:With reference to the second aspect, in a first possible implementation, the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
计算出所述光斑在所述CCD上的像素分布区域;Calculating a pixel distribution area of the spot on the CCD;
查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。Querying at least one grating associated with the pixel distribution region and determining the phase modulator to be adjusted associated with the at least one grating based on a mapping relationship between the grating and the phase modulator.
结合第二方面或第一种可能的实现方式,在第二种可能的实现方式中,所述对所述电信号进行低通滤波处理后生成低频噪声电信号之前,还包括:With reference to the second aspect or the first possible implementation manner, in the second possible implementation manner, before performing the low-pass filtering processing on the electrical signal to generate the low-frequency noise electrical signal, the method further includes:
对所述电信号进行放大处理。The electrical signal is amplified.
结合第二方面至第二种可能的实现方式中的任意一种,在第三种可能的实现方式中,所述根据光学自适应算法计算所述待调节的相位调制器的电压调节量包括:With reference to any one of the second aspect to the second possible implementation, in a third possible implementation, the calculating, by the optical adaptive algorithm, the voltage adjustment amount of the phase modulator to be adjusted includes:
根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。The voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
本发明实施例第三方面提供了一种光接收机,包括:光学天线、分光器、电荷耦合元件CCD、光学相控阵列OPA、光电转换模块、低通滤波模块、方差计算模块、相控参数生成模块和电压调节模块,所述OPA包括光栅阵列、相位调制器阵列和光耦合器,其中,
A third aspect of the embodiments of the present invention provides an optical receiver, including: an optical antenna, a beam splitter, a charge coupled device CCD, an optical phased array OPA, a photoelectric conversion module, a low pass filter module, a variance calculation module, and a phase control parameter. Generating a module and a voltage adjustment module, the OPA comprising a grating array, a phase modulator array, and an optical coupler, wherein
所述光学天线用于对接收的光信号进行汇聚处理后生成汇聚光信号;The optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal;
所述分光器用于对所述汇聚光信号进行分路处理后生成第一光信号和第二光信号;The beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;
所述CCD用于采集所述第一光信号的光斑;The CCD is configured to collect a spot of the first optical signal;
所述OPA用于通过所述光栅阵列接收所述第二光信号,并将经由所述光栅阵列和所述相位调制器阵列的波导光波由所述光耦合器处理后生成合路光信号;The OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
光电转换模块,用于对所述合路光信号进行光电转换处理后生成电信号;a photoelectric conversion module, configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal;
低通滤波模块,用于对所述电信号进行低通滤波处理后生成低频噪声电信号;a low pass filtering module, configured to perform low pass filtering on the electrical signal to generate a low frequency noise electrical signal;
方差计算模块,用于对所述低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差;a variance calculation module, configured to perform sampling processing on the low-frequency noise electrical signal to obtain at least one sampled value, and calculate a variance of the at least one sampled value;
相控参数生成模块,用于若所述方差大于方差阈值,根据所述光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量;a phase control parameter generating module, configured to determine a phase modulator to be adjusted according to position information of the spot if the variance is greater than a variance threshold, and calculate a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm ;
电压调节模块,用于根据所述电压调节量调节所述待调节的相位调制器的承载电压。And a voltage adjustment module, configured to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
结合第三方面,在第一种可能的实现方式中,所述相控参数生成模块包括:In conjunction with the third aspect, in a first possible implementation, the phase control parameter generating module includes:
计算单元,用于计算出所述光斑在所述CCD上的像素分布区域;a calculating unit, configured to calculate a pixel distribution area of the spot on the CCD;
查询单元,用于查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。And a query unit, configured to query at least one grating associated with the pixel distribution area, and determine the phase modulator to be adjusted associated with the at least one grating according to a mapping relationship between the grating and the phase modulator.
结合第三方面或第一种可能的实现方式,在第二种可能的实现方式中,所述光学天线、分光器和所述OPA的光栅阵列共光轴,所述分光器与所述光轴成45°角,所述光学天线的焦平面到所述分光器的中心点的距离为L1,所述CCD的中心点到所述分光器的中心点的连线垂直于所述光轴,所述CCD的中心点到所述分光器的中心点的距离为L2,其中,L1=L2。With reference to the third aspect or the first possible implementation manner, in a second possible implementation manner, the optical antenna, the optical splitter, and the grating array of the OPA share an optical axis, the optical splitter and the optical axis At an angle of 45°, the distance from the focal plane of the optical antenna to the center point of the beam splitter is L1, and the line connecting the center point of the CCD to the center point of the beam splitter is perpendicular to the optical axis. The distance from the center point of the CCD to the center point of the beam splitter is L2, where L1 = L2.
结合第三方面的第二种可能的实现方式,在第三种可能的实现方式中,所述光栅阵列位于所述光学天线的焦平面的前方,所述光栅阵列的最小直径为DOPA,所述CCD的最小直径为DCCD,则
In conjunction with the second possible implementation of the third aspect, in a third possible implementation, the grating array is located in front of a focal plane of the optical antenna, and the minimum diameter of the grating array is D OPA The minimum diameter of the CCD is D CCD , then
DOPA=2(F0-△L)*tanθ+(Dr/F0)*△L;D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;
DCCD=2F0*tanθ;D CCD = 2F 0* tan θ;
其中,F0为所述光学天线的焦距,△L为所述光栅阵列与所述光学天线的焦平面之间的距离,θ为所述汇聚光信号与所述光轴的之间的最大偏转角度,Dr为所述光学天线的直径。Wherein F 0 is the focal length of the optical antenna, ΔL is the distance between the grating array and the focal plane of the optical antenna, and θ is the maximum deflection between the concentrated optical signal and the optical axis Angle, D r is the diameter of the optical antenna.
结合第三方面至第三种可能的实现方式中的任意一种,在第四种可能的实现方式中,还包括:With reference to any one of the third aspect to the third possible implementation manner, in a fourth possible implementation manner, the method further includes:
放大模块,用于对所述光电转换模块生成的所述电信号进行放大处理,并将放大处理后的电信号发送至所述低通滤波模块。And an amplification module, configured to perform amplification processing on the electrical signal generated by the photoelectric conversion module, and send the amplified electrical signal to the low-pass filter module.
结合第三方面至第四种可能的实现方式中的任意一种,在第五种可能的实现方式中,所述相控参数生成模块用于根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。With reference to any one of the third aspect to the fourth possible implementation, in a fifth possible implementation, the phase control parameter generating module is configured to calculate the phase control to be adjusted according to a random parallel gradient algorithm The voltage adjustment amount of the device; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
实施本发明,具有如下有益效果:The implementation of the present invention has the following beneficial effects:
采用光学天线和OPA对自由空间的光信号进行接收,基于OPA的电光相位调制效应和光学自适应算法消除大气湍流噪声的影响,相对于现有技术的基于可变性的曲面镜和压电效应的空间相位调制,具有加工简单,功耗低和调节速度高的优点。同时,只需要有光信号照射的光栅对应的相位调制器进行调节,调节范围更加精确,计算量小。Optical antenna and OPA are used to receive free-space optical signals, and OPA-based electro-optical phase modulation effects and optical adaptive algorithms are used to eliminate the effects of atmospheric turbulence noise, compared to prior art variability-based curved mirrors and piezoelectric effects. Spatial phase modulation has the advantages of simple processing, low power consumption and high adjustment speed. At the same time, only the phase modulator corresponding to the grating illuminated by the optical signal needs to be adjusted, the adjustment range is more accurate, and the calculation amount is small.
为了更清楚地说明本发明实施例或现有技术中的技术方案,下面将对实施例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。In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the embodiments will be briefly described below. Obviously, the drawings in the following description are only some of the present invention. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative work.
图1为本发明实施例提供的一种光接收机的结构示意图;1 is a schematic structural diagram of an optical receiver according to an embodiment of the present invention;
图2是本发明实施例提供的一种OPA的结构示意图;2 is a schematic structural diagram of an OPA according to an embodiment of the present invention;
图3是图2中光栅的结构示意图;Figure 3 is a schematic structural view of the grating of Figure 2;
图4a是图1电信号的幅度变化图;
Figure 4a is a graph showing the amplitude variation of the electrical signal of Figure 1;
图4b是图1中电平噪声电信号的幅度变化图;Figure 4b is a graph showing the amplitude variation of the level noise electrical signal of Figure 1;
图5是本发明实施例提供的光接收机的一种光路结构示意图;FIG. 5 is a schematic structural diagram of an optical path of an optical receiver according to an embodiment of the present invention; FIG.
图6是本发明实施例提供的光接收机的另一光路结构示意图;6 is a schematic structural diagram of another optical path of an optical receiver according to an embodiment of the present invention;
图7是本发明实施例提供的一种基于光接收机的光信号调节方法的流程示意图;FIG. 7 is a schematic flowchart diagram of an optical signal adjustment method based on an optical receiver according to an embodiment of the present invention; FIG.
图8是本发明实施例提供的一种光接收机的另一结构示意图。FIG. 8 is another schematic structural diagram of an optical receiver according to an embodiment of the present invention.
下面将结合本发明实施例中的附图,对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.
参见图1,为本发明实施例提供的一种光接收机的结构示意图,在本发明实施例中,光学透镜为接收透镜10,接收透镜为一个凸透镜,如菲涅尔透镜。所述光接收机包括:接收透镜10、分光器11、光电探测器12、OPA13、驱动器14、低通滤波器15、处理器16和CCD(Charge Coupled Device,电荷耦合元件,简称CCD)17,OPA(Optical Phased Array,光学相控阵列,简称OPA)13包括光栅阵列、相位调制器阵列和光耦合器,OPA13中相位光栅阵列中的光栅的数量等于相位调制器阵列中相位调制器的数量,光栅和相位调制器为一一对应关系。1 is a schematic structural diagram of an optical receiver according to an embodiment of the present invention. In the embodiment of the present invention, an optical lens is a receiving lens 10, and a receiving lens is a convex lens, such as a Fresnel lens. The optical receiver includes: a receiving lens 10, a beam splitter 11, a photodetector 12, an OPA 13, a driver 14, a low pass filter 15, a processor 16, and a CCD (Charge Coupled Device, CCD for short) 17, OPA (Optical Phased Array, OPA for short) 13 includes a grating array, a phase modulator array, and an optical coupler. The number of gratings in the phase grating array in OPA13 is equal to the number of phase modulators in the phase modulator array. And the phase modulator has a one-to-one correspondence.
参见图2,为本发明实施例提供的OPA的结构示意图,OPA包括光栅阵列、相位调制器阵列和光耦合器,光栅、相位调制器和光耦合器之间通过波导进行连接。图3中图2中的一个光栅的结构示意图,光栅由二氧化硅基片、硅光栅和硅波导组成,光信号照射在硅光栅上,硅光栅将光信号转换为波导光波,通过硅波导传输到光耦合器的输入端口。光信号垂直或倾斜照射在光栅阵列上时,光信号在光栅阵列上形成光斑,光栅阵列中的部分光栅会接收到光信号,有光信号照射的光栅将表面的光波耦合进单模的波导,分别转换为波导光波。光栅阵列中的光栅的数量为M,M≥2。在实际应用中,M的取值一般非常大,保证光信号以一定的角度倾斜照射到光学天线时,从光学天线输出的光信号不
会超出光栅阵列的边缘,这样可以尽可能捕获更多的光信号。2 is a schematic structural diagram of an OPA according to an embodiment of the present invention. The OPA includes a grating array, a phase modulator array, and an optical coupler. The grating, the phase modulator, and the optical coupler are connected by a waveguide. FIG. 3 is a schematic structural view of a grating in FIG. 2, the grating is composed of a silicon dioxide substrate, a silicon grating and a silicon waveguide, and the optical signal is irradiated on the silicon grating, and the silicon grating converts the optical signal into a waveguide light wave, and transmits the light through the silicon waveguide. To the input port of the optocoupler. When the optical signal is vertically or obliquely irradiated on the grating array, the optical signal forms a spot on the grating array, and a part of the grating in the grating array receives the optical signal, and the grating irradiated by the optical signal couples the surface light wave into the single-mode waveguide. Converted to waveguide light waves, respectively. The number of gratings in the grating array is M, M ≥ 2. In practical applications, the value of M is generally very large, and when the optical signal is obliquely irradiated to the optical antenna at a certain angle, the optical signal output from the optical antenna is not
It will exceed the edge of the raster array so that it captures as much light as possible.
每个光栅均连接一个相位调制器,相位调制器的输出端口与光耦合器的输入端口连接。在没有相位调制时,经过每条光栅和相位调制器到达光耦合器的波导光波的相位改变均相等,即每条光栅-相位调制器-光耦合器的输入端口之间的光程差相等。相位调制器可以通过电光效应或电流注入效应来调制波导光波的相位,具有高速的相位调节能力。具体相位调制方法可以通过驱动器改变对应的相位调制器的承载电压来实现,在一定电压范围内相位调制器对波导光波的相位的调制过程是线性的。光耦合器可以为平面透镜耦合器,光耦合器为多端口输入单端口输入器件,如果光栅的数量太多,可以采用光耦合器级联的方式将数量众多的垂直光耦合器连接起来,光耦合器的输出端口输出合路光信号,合路光信号直接发送给光电探测器12,或者经过尾纤在发送给光电探测器12。Each grating is connected to a phase modulator, and the output port of the phase modulator is connected to the input port of the optical coupler. In the absence of phase modulation, the phase changes of the waveguide light waves passing through each of the grating and phase modulators to the optical coupler are equal, that is, the optical path difference between the input ports of each of the grating-phase modulator-optical couplers is equal. The phase modulator can modulate the phase of the waveguide light wave by electro-optical effect or current injection effect, and has high-speed phase adjustment capability. The specific phase modulation method can be realized by the driver changing the carrying voltage of the corresponding phase modulator, and the modulation process of the phase of the waveguide light wave by the phase modulator is linear within a certain voltage range. The optical coupler can be a planar lens coupler, and the optical coupler is a multi-port input single-port input device. If the number of gratings is too large, a large number of vertical optical couplers can be connected by optical coupler cascading, light The output port of the coupler outputs a combined optical signal, and the combined optical signal is directly sent to the photodetector 12 or sent to the photodetector 12 via the pigtail.
OPA可由微纳制造工艺在一个平板硅基片上制作出来。除了硅材料,氮化硅、铟磷等高折射率低损耗光学材料均可用于本发明实施例中的OPA的制作。OPA can be fabricated on a flat silicon substrate by a micro-nano fabrication process. In addition to the silicon material, a high refractive index low loss optical material such as silicon nitride or indium phosphorus can be used for the production of the OPA in the embodiment of the present invention.
其中,下面结合图1对所述光接收机的工作过程进行说明,图1中实线箭头表示光信号,虚线箭头表示电信号。光发射机(图中未画出)将数字信息通过电光调制器调制到相干光载波上生成光信号,电光调制的过程可以是内调制或外调制,本发明不作限制,将光信号通过发送透镜发射出去,光信号在自由空间传输的过程中会受到大气湍流的影响,导致光信号的波前相位会发生畸变,光信号到达光接收机的光学天线时,发生波前相位畸变的光信号无法汇聚到一个点,同时具备相关性,在光学天线表面形成直径随机变化的弥散光斑。光学天线10用于对接收的光信号进行汇聚处理后生成汇聚光信号,光发射机发送的光信号在自由空间传输的过程中,受到大气湍流的影响会造成扩散效应,光学天线10将从自由空间传输过来的光信号进行汇聚处理,以较小光信号的直径,汇聚处理后生成汇聚光信号;分光器11用于将光学天线10生成的汇聚光信号进行分光处理,分光处理后生成第一光信号和第二光信号,第一光信号和第二光信号的光学特性完全相同,CCD17用于对第一光信号进行成像,生成第一光信号的光斑;第二光信号照射在OPA13的光栅阵列上,并将经由
光栅阵列和相位调制器阵列的至少一个波导光波在光耦合器进行叠加处理后生成合路光信号。第二光信号照射在光栅阵列上时,光栅阵列上由部分光栅可以检测到光信号,有光信号照射的光栅将检测到的光信号耦合成波导光波,波导光波经过对应的相位调制器输入到光耦合器进行耦合;没有光信号照射的光栅不会产生波导光波;此时相位调制器不会对波导光波进行相位调制操作。光电探测器12用于将对OPA13输出的合路光信号进行光电转换处理,光电转换处理后生成电信号;低通滤波器用于对所述电信号进行低通滤波处理后生成低频噪声电信号。光信号的频率非常高(以GHz为单位),大气湍流噪声的频率远低于光信号的频率,其频率一般小于10kHz,因此大气湍流噪声是光信号的基础上施加的一个慢包络噪声。如图4a中光电探测器输入的电信号i0的幅度变化图,在局部短时间内,电信号的幅度变化很小,如图4a中虚线框所示。低通滤波器滤除电信号i0中的高频部分得到低频噪声电信号i1(如图4b所示),低频噪声电信号i1的幅度变化反应大气湍流噪声的大小。Here, the operation of the optical receiver will be described below with reference to FIG. 1. In FIG. 1, solid arrows indicate optical signals, and dotted arrows indicate electrical signals. The optical transmitter (not shown) modulates the digital information onto the coherent optical carrier by the electro-optic modulator to generate an optical signal. The process of the electro-optic modulation may be internal modulation or external modulation. The invention does not limit the optical signal to the transmitting lens. When transmitting, the optical signal will be affected by atmospheric turbulence during the free space transmission, resulting in distortion of the wavefront phase of the optical signal. When the optical signal reaches the optical antenna of the optical receiver, the optical signal of the wavefront phase distortion cannot be generated. Converging to a point with correlation, a diffuse spot of randomly varying diameters is formed on the surface of the optical antenna. The optical antenna 10 is configured to converge the received optical signal to generate a concentrated optical signal. In the process of transmitting in the free space, the optical signal transmitted by the optical transmitter is affected by atmospheric turbulence, which may cause a diffusion effect, and the optical antenna 10 will be free. The optical signal transmitted from the space is subjected to convergence processing, and the convergence optical signal is generated by the convergence of the smaller optical signal. The optical splitter 11 is configured to perform the spectral processing on the concentrated optical signal generated by the optical antenna 10, and generate the first after the optical processing. The optical signal and the second optical signal have the same optical characteristics of the first optical signal and the second optical signal, and the CCD 17 is configured to image the first optical signal to generate a spot of the first optical signal; the second optical signal is irradiated on the OPA13. On the grating array, at least one waveguide light wave passing through the grating array and the phase modulator array is superimposed on the optical coupler to generate a combined optical signal. When the second optical signal is irradiated on the grating array, the grating signal can detect the optical signal by the partial grating, and the grating illuminated by the optical signal couples the detected optical signal into the waveguide optical wave, and the waveguide optical wave is input to the corresponding phase modulator. The optical coupler is coupled; the grating without the illumination of the optical signal does not generate the waveguide light wave; at this time, the phase modulator does not perform the phase modulation operation on the waveguide light wave. The photodetector 12 is configured to perform photoelectric conversion processing on the combined optical signal outputted by the OPA 13, and generate an electrical signal after the photoelectric conversion processing; the low-pass filter is configured to perform low-pass filtering processing on the electrical signal to generate a low-frequency noise electrical signal. The frequency of the optical signal is very high (in GHz). The frequency of atmospheric turbulence noise is much lower than the frequency of the optical signal, and its frequency is generally less than 10 kHz. Therefore, atmospheric turbulence noise is a slow envelope noise applied on the basis of the optical signal. As shown in the amplitude variation diagram of the electrical signal i 0 input by the photodetector in Fig. 4a, the amplitude of the electrical signal changes little in a short time, as shown by the dashed box in Fig. 4a. The low-pass filter filters out the high-frequency portion of the electrical signal i 0 to obtain the low-frequency noise electrical signal i 1 (as shown in Figure 4b), and the amplitude variation of the low-frequency noise electrical signal i 1 reflects the magnitude of the atmospheric turbulent noise.
处理器16用于对低通滤波器输出的低频噪声电信号进行采样处理,具体过程可以为:根据预设的采样周期获取至少一个采样值(例如采样值的数量大于10个),对至少一个采样值计算其方差,如果计算得到的方差大于方差阈值,说明大气湍流噪声的影响不可忽略,处理器16根据CCD17采集的光斑的位置信息确定待调节的相位调制器,例如,每个相位调制器设置有一个唯一标识,通过唯一标识表示待调节的相位调制器;待调节的相位调制器即第二光信号照射的部分光栅对应的相位调制器,处理器16根据预设的自适应算法为待调节的相位调制器生成一个电压调节量,电压调节量分为正电压调节量和负电压调节量,正电压调节量用于增加相位调制器上的承载电压,负电压调节量用于减少相位调制器上的承载电压。处理器16向驱动器14发送相位调制节示消息,所述相位调节指示消息用于指示所述所述驱动器根据所述电压调节量调节所述待调节的相位调制器的承载电压。The processor 16 is configured to perform sampling processing on the low-frequency noise electrical signal output by the low-pass filter. The specific process may be: acquiring at least one sampling value according to a preset sampling period (for example, the number of sampling values is greater than 10), for at least one The sampled value calculates its variance. If the calculated variance is greater than the variance threshold, the influence of atmospheric turbulence noise is not negligible. The processor 16 determines the phase modulator to be adjusted according to the position information of the spot collected by the CCD 17, for example, each phase modulator. A unique identifier is provided, and the phase modulator to be adjusted is represented by a unique identifier; the phase modulator to be adjusted is a phase modulator corresponding to a partial grating illuminated by the second optical signal, and the processor 16 is configured according to a preset adaptive algorithm. The adjusted phase modulator generates a voltage adjustment amount, the voltage adjustment amount is divided into a positive voltage adjustment amount and a negative voltage adjustment amount, the positive voltage adjustment amount is used to increase the load voltage on the phase modulator, and the negative voltage adjustment amount is used to reduce the phase modulation Carrying voltage on the device. The processor 16 transmits a phase modulation indication message to the driver 14, the phase adjustment indication message for instructing the driver to adjust the carrier voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
具体的,相位调节指示消息中可携带待调节的相位调制器的标识和所述待调节的相位调制器的电压调节量。优选的,相位调制器阵列中的相位调制器按照顺序进行排列,通过位图的方式来表示待调节的相位调制器,例如,相位调节指示消息中携带的待调节的相位调制器的标识表示为:Address
(1,0,1,1,……,1,1),其中,1表示需要进行相位调节的相位调制器,0表示不需要进行相位调节的相位调制器,相位调制指示消息中携带的电压调节量表示为:Voltage(U1,U2,……,Un),U1表示第1个相位调制器上的电压调节量,Un表示第n个相位调制器的电压调节量,Un可以用正负值来表示正电压调节量和负电压调节量。驱动器14接收到处理器16发送的相位调节指示消息后,根据所述地址确定需要待调节的相位调制器,以及根据所述电压调节量调节所述相位调制器的承载电压,从而改变经过待调节的相位调制器的的波导光波的相位,使光耦合器输入的波导光波的相位均相同,即使光耦合器输入的波导光波具备相干性,光耦合器对相位相同的波导光波进行相干叠加处理生成合路光信号。其中,处理器13可以为专用的集成电路,或通用的集成电路,例如DSP或FPGA,本发明不作限制。Specifically, the phase adjustment indication message may carry an identifier of the phase modulator to be adjusted and a voltage adjustment amount of the phase modulator to be adjusted. Preferably, the phase modulators in the phase modulator array are arranged in order, and the phase modulator to be adjusted is represented by a bitmap, for example, the identifier of the phase modulator to be adjusted carried in the phase adjustment indication message is represented as :Address
(1,0,1,1,...,1,1), where 1 denotes a phase modulator requiring phase adjustment, 0 denotes a phase modulator that does not require phase adjustment, and the phase modulation indicates a voltage carried in the message The adjustment amount is expressed as: Voltage (U1, U2, ..., Un), U1 represents the voltage adjustment amount on the first phase modulator, Un represents the voltage adjustment amount of the nth phase modulator, and Un can use positive and negative values. To indicate the positive voltage regulation amount and the negative voltage regulation amount. After receiving the phase adjustment indication message sent by the processor 16, the driver 14 determines a phase modulator that needs to be adjusted according to the address, and adjusts a load voltage of the phase modulator according to the voltage adjustment amount, so that the change is to be adjusted. The phase of the waveguide light wave of the phase modulator is such that the phase of the waveguide light wave input by the optical coupler is the same. Even if the waveguide light wave input by the optical coupler has coherence, the optical coupler performs coherent superposition processing on the waveguide light wave of the same phase. Combine optical signals. The processor 13 may be a dedicated integrated circuit, or a general-purpose integrated circuit, such as a DSP or an FPGA, and the invention is not limited thereto.
重复上述步骤,光电探测器12相位调节后的合路光信号转换为电信号,低通滤波器15对电信号进行采样处理得到至少一个采样值,处理器16计算至少一个采样值的方差,若计算得到的方差仍然大于方差阈值,继续指示驱动器14对OPA的相位调制器进行相位调节操作,直到计算得到的方差小于方差阈值。Repeating the above steps, the combined optical signal of the phase adjustment of the photodetector 12 is converted into an electrical signal, the low pass filter 15 samples the electrical signal to obtain at least one sampled value, and the processor 16 calculates the variance of at least one sampled value. The calculated variance is still greater than the variance threshold and continues to instruct the driver 14 to perform a phase adjustment operation on the phase modulator of the OPA until the calculated variance is less than the variance threshold.
可以理解的是,光学天线也可以是反射天线,反射天线用于将自由空间的光信号进行汇聚和反射处理生成汇聚光信号,传输给分光器进行分光处理生成第一光信号和第二光信号,CCD接收第一光信号,OPA接收第二光信号,电路部分的工作原理和图1中的相同,反射天线的结构可以参照现有技术中的描述,此处不再赘述。It can be understood that the optical antenna can also be a reflective antenna, and the reflective antenna is configured to converge and reflect the optical signal in the free space to generate a concentrated optical signal, and transmit the optical signal to the optical splitter for splitting to generate the first optical signal and the second optical signal. The CCD receives the first optical signal, and the OPA receives the second optical signal. The working principle of the circuit portion is the same as that in FIG. 1. The structure of the reflective antenna can be referred to the description in the prior art, and details are not described herein again.
可选的,所述根据所述光斑的位置信息确定待调节的相位调制器包括:Optionally, the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
计算出所述光斑在所述CCD上的像素分布区域;Calculating a pixel distribution area of the spot on the CCD;
查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。Querying at least one grating associated with the pixel distribution region and determining the phase modulator to be adjusted associated with the at least one grating based on a mapping relationship between the grating and the phase modulator.
具体的,CCD包括大量的紧密排列的像素,CCD上的像素预先划分为多个网格,每个网络对应光栅阵列上的一个光栅,网格的数量等于光栅阵列中的光栅的数量,第一光信号照射的CCD上形成光斑,光斑的形状一般接近于圆形,处理器16根据获取CCD上光斑的像素分布区域,查询像素分布区域对应
的网格,根据网格和光栅的映射关系确定第二光信号在OPA上对应的光栅,根据光栅和相位调制器一一对应的关系,OPA中每个光栅对应一个相位调制器,由此可以确定待调节的相位调制器,可以通过位图或标识的方式标识待调节的相位调制器。Specifically, the CCD includes a plurality of closely arranged pixels, and the pixels on the CCD are pre-divided into a plurality of grids, each of which corresponds to a grating on the grating array, and the number of the grids is equal to the number of gratings in the grating array, first A spot is formed on the CCD illuminated by the light signal, and the shape of the spot is generally close to a circle. The processor 16 searches for the pixel distribution area according to the pixel distribution area of the spot on the CCD.
Grid, according to the mapping relationship between the grid and the grating, the corresponding grating of the second optical signal on the OPA is determined. According to the one-to-one correspondence between the grating and the phase modulator, each grating in the OPA corresponds to a phase modulator, thereby The phase modulator to be adjusted is determined, and the phase modulator to be adjusted can be identified by means of a bitmap or an identification.
可选的,所述分光器和所述OPA的光栅阵列共光轴,所述光学天线、分光器和所述OPA的光栅阵列共光轴,所述分光器与所述光轴成45°角,所述光学天线的焦平面到所述分光器的中心点的距离为L1,所述CCD的中心点到所述分光器的中心点的连线垂直于所述光轴,所述CCD的中心点到所述分光器的中心点的距离为L2,其中,L1=L2。Optionally, the optical splitter and the grating array of the OPA share an optical axis, the optical antenna, the optical splitter and the grating array of the OPA share an optical axis, and the optical splitter forms an angle of 45° with the optical axis. a distance from a focal plane of the optical antenna to a center point of the beam splitter is L1, a line from a center point of the CCD to a center point of the beam splitter being perpendicular to the optical axis, a center of the CCD The distance from the point to the center point of the beam splitter is L2, where L1 = L2.
具体的,光学天线、分光器、OPA的光栅阵列共光轴表示光轴经过光学天线的中心点、分光器的中心点和光栅阵列的中心点,且光轴与光学天线的焦平面垂直及光栅阵列垂直;分光器与光轴成45°角,这样分光器可以将入射的汇聚光信号分为与汇聚光信号平行的第二光信号、与汇聚光信号垂直的第一光信号,这种垂直几何关系便于计算和调节光接收机中光学元件的位置;光学天线的焦平面到分光器的中心点的距离为L1,CCD的中心点到分光器的中心点的连线垂直于光轴,CCD的中心点到分光器的中心点的距离为L2,L1=L2,即CCD位于基于CCD的中心点的等效焦平面上,在这种位置关系上,第一光信号照射在CCD形成的光斑的尺寸达到最小,可以减小CCD的尺寸,降低成本。Specifically, the common optical axis of the optical antenna, the optical splitter, and the OPA grating array indicates that the optical axis passes through the center point of the optical antenna, the center point of the optical splitter, and the center point of the grating array, and the optical axis is perpendicular to the focal plane of the optical antenna and the grating The array is vertical; the beam splitter is at an angle of 45° to the optical axis, such that the splitter can split the incident concentrated optical signal into a second optical signal parallel to the concentrated optical signal and a first optical signal perpendicular to the concentrated optical signal. The geometric relationship is convenient for calculating and adjusting the position of the optical component in the optical receiver; the distance from the focal plane of the optical antenna to the center point of the optical splitter is L1, and the line connecting the center point of the CCD to the center point of the optical splitter is perpendicular to the optical axis, CCD The distance from the center point to the center point of the beam splitter is L2, L1=L2, that is, the CCD is located on the equivalent focal plane based on the center point of the CCD. In this positional relationship, the first light signal is irradiated to the spot formed by the CCD. The smallest size can reduce the size of the CCD and reduce the cost.
可选的,所述光接收机还包括放大器18,放大器18连接在光电探测器12和低通滤波器15之间,放大器18用于对光电探测器12生成的所述电信号进行放大处理,并将放大处理后的电信号发送至低通滤波器15。其中,放大器18可以为跨导放大器。Optionally, the optical receiver further includes an amplifier 18 connected between the photodetector 12 and the low pass filter 15 for amplifying the electrical signal generated by the photodetector 12, The amplified electrical signal is sent to the low pass filter 15. Among them, the amplifier 18 can be a transconductance amplifier.
可选的,所述光接收机还包括:放大器,所述放大器连接在所述光电探测器和所述低通滤波器之间,所述放大器用于对所述光电探测器生成的所述电信号进行放大处理,并将放大处理后的电信号发送至所述低通滤波器。Optionally, the optical receiver further includes: an amplifier connected between the photodetector and the low pass filter, the amplifier being used to generate the electricity generated by the photodetector The signal is amplified, and the amplified electrical signal is sent to the low pass filter.
具体的,光电探测器12可以为光电雪崩二极管,放大器可以为跨导放大器。Specifically, the photodetector 12 can be a photoelectric avalanche diode, and the amplifier can be a transconductance amplifier.
可选的,所述根据算法光学自适应算法计算所述待调节的相位调制器的电
压调节量包括:Optionally, the calculating, according to an algorithm optical adaptive algorithm, the power of the phase modulator to be adjusted
The pressure adjustment amount includes:
根据随机并行梯度算法计算所述待调节的相位调制器的电压调节量;其中,所述待调节的相位调制器中各个相位调制器的电压调节量符合伯努利分布。The voltage adjustment amount of the phase modulator to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase modulator in the phase modulator to be adjusted conforms to a Bernoulli distribution.
具体的,电压调节量指的是相位调制器上的承载电压增加量或减少量,设有N个待调节的相位调制器,各个相位控制器的电压调节量为Voltage(△U1,△U2,△U3,……,△Un),Voltage中的各个电压调节量符合伯努利分布。采用随机并行梯度算法能是经过N个待调节的相位控制器的波导光波的相位趋于一致,即N路波导光波具有相干性,光耦合器能进行相干叠加处理,具有良好的收敛性。Specifically, the voltage adjustment amount refers to the amount of increase or decrease of the load voltage on the phase modulator, and is provided with N phase modulators to be adjusted, and the voltage adjustment amount of each phase controller is Voltage (ΔU1, ΔU2, ΔU3, ..., ΔUn), the respective voltage adjustment amounts in the Voltage are in accordance with the Bernoulli distribution. The random parallel gradient algorithm can be that the phase of the waveguide light wave passing through the N phase controllers to be adjusted tends to be uniform, that is, the N-channel waveguide light wave has coherence, and the optical coupler can perform coherent superposition processing with good convergence.
可选的,所述光栅阵列位于所述光学天线的焦平面的前方,所述光栅阵列的最小直径为DOPA,所述CCD的最小直径为DCCD,则Optionally, the grating array is located in front of a focal plane of the optical antenna, the minimum diameter of the grating array is D OPA , and the minimum diameter of the CCD is D CCD , then
DOPA=2(F0-△L)*tanθ+(Dr/F0)*△L;D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;
DCCD=2F0*tanθ;D CCD = 2F 0* tan θ;
其中,F0为所述光学天线的焦距,△L为所述光栅阵列与所述光学天线的焦平面之间的距离,θ为所述汇聚光信号与所述光轴的之间的最大偏转角度,Dr为所述光学天线的直径。Wherein F 0 is the focal length of the optical antenna, ΔL is the distance between the grating array and the focal plane of the optical antenna, and θ is the maximum deflection between the concentrated optical signal and the optical axis Angle, D r is the diameter of the optical antenna.
具体的,结合图5和图6对本发明实施例的光路的结构进行说明,以光学透镜为接收透镜为例,光学天线的直径为Dr,光学天线的焦距为F0,OPA的光栅阵列与光学天线的光轴垂直,且光学天线的光轴经过光栅阵列的中心点,分光器位于光学天线和光栅阵列之间,分光器与光轴成45°角,且光学天线的光轴经过分光器的中心点。CCD位于光学天线的等效焦平面上,具体位置为:CCD的中心点与分光器的中心点的连线垂直于光轴,且连线的距离等于分光器的中心点到焦平面的距离。光栅阵列与光学天线的焦平面的距离为△L,△L的大小取决于光栅阵列中的光栅的数量M,设光栅阵列中每个光栅的面积为S0,M足够大,保证光束在垂直照射或倾斜照射,以及大气湍流的作用下,产生的光斑的面积小于光栅阵列的总面积M*S0。为了实现高精度的相位调制,可以增加光栅的数量;为了减低光学自适应控制的复杂度,可以减少光栅的数量。
Specifically, the structure of the optical path of the embodiment of the present invention is described with reference to FIG. 5 and FIG. 6. Taking the optical lens as the receiving lens as an example, the diameter of the optical antenna is D r , the focal length of the optical antenna is F 0 , and the grating array of the OPA is The optical axis of the optical antenna is perpendicular, and the optical axis of the optical antenna passes through the center point of the grating array, the optical splitter is located between the optical antenna and the grating array, the optical splitter is at an angle of 45° with the optical axis, and the optical axis of the optical antenna passes through the optical splitter The center point. The CCD is located on the equivalent focal plane of the optical antenna. The specific position is that the line connecting the center point of the CCD and the center point of the beam splitter is perpendicular to the optical axis, and the distance of the line is equal to the distance from the center point of the beam splitter to the focal plane. The distance between the grating array and the focal plane of the optical antenna is ΔL, and the magnitude of ΔL depends on the number M of gratings in the grating array. The area of each grating in the grating array is S 0 , M is large enough to ensure that the beam is vertical Under the action of illumination or oblique illumination, as well as atmospheric turbulence, the area of the generated spot is smaller than the total area M*S 0 of the grating array. In order to achieve high-precision phase modulation, the number of gratings can be increased; in order to reduce the complexity of optical adaptive control, the number of gratings can be reduced.
规定光接收机的光信号与光轴的最大偏转角度为θ,当光信号倾斜照射在光学天线上时,CCD上的光斑的位置发生偏移,在焦平面上的光斑的偏移量最大值为Xshift=F0*tanθ,CCD的最小直径为DCCD=2*Xshift。分光器的尺寸足够大,以便接收到光学天线发射的整个汇聚光信号。OPA的光栅阵列的最小直径DOPA由光束汇聚光信号的的最大偏转角度决定的,从空间几何关系出发,DOPA的计算公式可表示为:The maximum deflection angle of the optical signal and the optical axis of the optical receiver is θ. When the optical signal is obliquely irradiated on the optical antenna, the position of the spot on the CCD is shifted, and the maximum deviation of the spot on the focal plane is For X shift = F 0 * tan θ, the minimum diameter of the CCD is D CCD = 2 * X shift . The size of the beam splitter is large enough to receive the entire concentrated optical signal emitted by the optical antenna. The minimum diameter D OPA of the OPA grating array is determined by the maximum deflection angle of the beam converging optical signal. From the spatial geometric relationship, the calculation formula of D OPA can be expressed as:
DOPA=2(F0-△L)*tanθ+(Dr/F0)*△LD OPA =2(F 0 -△L)*tanθ+(D r /F 0 )*△L
下表1为一个典型的光学系统的参数表。其中,光学天线的直径Dr=80mm,其焦距F0=300mm,每个光栅的面积S0=30*30μm2,光栅的数量M=20*20个矩形阵列接收光斑,光栅阵列到光学天线的焦平面的距离ΔL=2.3mm。当θ=1°入射时,OPA的光栅阵列的边长为11mm,CCD的直径为10.5mm;当θ=2.5°时,OPA的光栅阵列的边长为27.5mm,CCD的直径为26.2mm。其中,所述OPA的光栅阵列可以用微纳加工方法制备。Table 1 below is a list of parameters for a typical optical system. Wherein, the optical antenna has a diameter D r = 80 mm, a focal length F 0 = 300 mm, an area of each grating S 0 = 30 * 30 μm 2 , a number of gratings M = 20 * 20 rectangular array receiving spots, a grating array to an optical antenna The distance of the focal plane is ΔL = 2.3 mm. When θ=1° is incident, the side length of the grating array of OPA is 11 mm, and the diameter of CCD is 10.5 mm; when θ=2.5°, the side length of the grating array of OPA is 27.5 mm, and the diameter of CCD is 26.2 mm. Wherein, the grating array of the OPA can be prepared by a micro-nano processing method.
需要说明的是,本实施例的所述的光栅阵列形状并不限定为圆形,也可以为矩形或其他形状,光栅阵列的面积需要满足大于π*DOPA*DOPA/4的条件。同时CCD的形状也不限定为圆形,也可以是矩形或其他形态,CCD的面积需要满足大于π*DCCD*DCCD/4的条件。
It should be noted that the shape of the grating array of the embodiment is not limited to a circular shape, and may be a rectangle or other shape, and the area of the grating array needs to satisfy a condition larger than π*D OPA *D OPA /4. At the same time, the shape of the CCD is not limited to a circular shape, and may be a rectangle or other form, and the area of the CCD needs to satisfy a condition larger than π*D CCD *D CCD /4.
表1Table 1
可选的,所述光接收机还包括:数据恢复模块19,所述数据恢复模块用于对所述放大器输入的电信号进行解调处理,解调处理后得到电信号中加载的数字信息。Optionally, the optical receiver further includes: a data recovery module 19, configured to perform demodulation processing on the electrical signal input by the amplifier, and obtain digital information loaded in the electrical signal after demodulation processing.
实施本发明的实施例,采用结构紧凑的平板OPA,结构简单,具有加工简单和可靠性的优点;OPA采用CMOS工艺制造,具有低功耗的优点。同时基于电光效应和光学自适应算法进行相位调节,速率可达GHz的数量级,具有调节速度高的优点。只需要有光信号照射的光栅对应的相位调制器进行调节,调节范围更加精确,计算量小。The embodiment of the present invention adopts a compact flat panel OPA, has a simple structure, and has the advantages of simple processing and reliability; the OPA is manufactured by a CMOS process and has the advantages of low power consumption. At the same time, phase adjustment based on electro-optical effect and optical adaptive algorithm, the rate can reach the order of GHz, and has the advantage of high adjustment speed. Only the phase modulator corresponding to the grating illuminated by the optical signal needs to be adjusted, the adjustment range is more accurate, and the calculation amount is small.
参见图7,为本发明实施例提供的一种基于光接收机的光信号调节方法,在本发明实施例中,所述方法包括:FIG. 7 is a schematic diagram of an optical signal adjustment method based on an optical receiver according to an embodiment of the present invention. In the embodiment of the present invention, the method includes:
S701、对光耦合器输出的合路光信号进行光电转换处理后生成电信号。S701. Perform photoelectric conversion processing on the combined optical signal output by the optical coupler to generate an electrical signal.
S702、对所述电信号进行低通滤波处理后生成低频噪声电信号。S702. Perform low-pass filtering processing on the electrical signal to generate a low-frequency noise electrical signal.
具体的,可通过低通滤波器进行低通滤波处理,低通滤波器对所述电信号进行低通滤波处理后生成低频噪声电信号。光信号的频率非常高(以GHz为单位),大气湍流噪声的频率远低于光信号的频率,其频率一般小于10kHz,
因此大气湍流噪声是光信号的基础上施加的一个慢包络噪声。如图3a中光电探测器输入的电信号i0的幅度变化图,在局部短时间内,电信号的幅度变化很小,如图4a中虚线框所示。低通滤波器滤除电信号i0中的高频部分得到低频噪声电信号i1(如图4b所示),低频噪声电信号i1的幅度变化反应大气湍流噪声的大小。Specifically, the low-pass filter processing may be performed by a low-pass filter, and the low-pass filter performs low-pass filtering processing on the electrical signal to generate a low-frequency noise electrical signal. The frequency of the optical signal is very high (in GHz). The frequency of atmospheric turbulence noise is much lower than the frequency of the optical signal, and its frequency is generally less than 10 kHz. Therefore, atmospheric turbulence noise is a slow envelope noise applied on the basis of the optical signal. As shown in the amplitude variation diagram of the electrical signal i 0 input by the photodetector in Fig. 3a, the amplitude of the electrical signal changes little in a short time, as shown by the dashed box in Fig. 4a. The low-pass filter filters out the high-frequency portion of the electrical signal i 0 to obtain the low-frequency noise electrical signal i 1 (as shown in Figure 4b), and the amplitude variation of the low-frequency noise electrical signal i 1 reflects the magnitude of the atmospheric turbulent noise.
S703、对低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差。S703. Perform sampling processing on the low frequency noise electrical signal to obtain at least one sampling value, and calculate a variance of the at least one sampling value.
具体的,光接收机包括:光学天线、分光器、电荷耦合元件CCD、光学相控阵列OPA;其中,所述OPA包括光栅阵列、相位调制器阵列和光耦合器,光学天线可以为接收透镜或反射天线。Specifically, the optical receiver includes: an optical antenna, a beam splitter, a charge coupled device CCD, and an optical phased array OPA; wherein the OPA includes a grating array, a phase modulator array, and an optical coupler, and the optical antenna can be a receiving lens or a reflection antenna.
光发射机(图中未画出)将数字信息通过电光调制器调制到相干光载波上生成光信号,电光调制的过程可以是内调制或外调制,本发明不作限制,将光信号通过发送透镜发射出去,光信号在自由空间传输的过程中会受到大气湍流的影响,导致光信号的波前相位会发生畸变,光信号到达光接收机的光学天线时,发生波前相位畸变的光信号无法汇聚到一个点,同时具备相关性,在光学天线表面形成直径随机变化的弥散光斑。光学天线用于对接收的光信号进行汇聚处理后生成汇聚光信号,光发射机发送的光信号在自由空间传输的过程中,受到大气湍流的影响会造成扩散效应,光学天线将从自由空间传输过来的光信号进行汇聚处理,以较小光信号的直径,汇聚处理后生成汇聚光信号;分光器用于将光学天线10生成的汇聚光信号进行分光处理,分光处理后生成第一光信号和第二光信号,第一光信号和第二光信号的光学特性完全相同,CCD用于对第一光信号进行成像,生成第一光信号的光斑;第二光信号照射在OPA的光栅阵列上,并将经由光栅阵列和相位调制器阵列的至少一个波导光波在光耦合器进行叠加处理后生成合路光信号。第二光信号照射在光栅阵列上时,光栅阵列上由部分光栅可以检测到光信号,有光信号照射的光栅将检测到的光信号耦合成波导光波,波导光波经过对应的相位调制器输入到光耦合器进行耦合;没有光信号照射的光栅不会产生波导光波;此时相位调制器不会对波导光波进行相位调制操作。The optical transmitter (not shown) modulates the digital information onto the coherent optical carrier by the electro-optic modulator to generate an optical signal. The process of the electro-optic modulation may be internal modulation or external modulation. The invention does not limit the optical signal to the transmitting lens. When transmitting, the optical signal will be affected by atmospheric turbulence during the transmission of free space, causing the wavefront phase of the optical signal to be distorted. When the optical signal reaches the optical antenna of the optical receiver, the optical signal of the wavefront phase distortion cannot be generated. Converging to a point with correlation, a diffuse spot of randomly varying diameters is formed on the surface of the optical antenna. The optical antenna is used to converge the received optical signal to generate a concentrated optical signal. In the process of free space transmission, the optical signal transmitted by the optical transmitter is affected by atmospheric turbulence, which will cause a diffusion effect, and the optical antenna will be transmitted from free space. The incoming optical signal is subjected to convergence processing to generate a concentrated optical signal by focusing on the diameter of the smaller optical signal; the optical splitter is configured to perform spectral processing on the concentrated optical signal generated by the optical antenna 10, and generate a first optical signal and a first optical signal after the optical splitting process. The optical characteristics of the first optical signal and the second optical signal are exactly the same, the CCD is used to image the first optical signal to generate a spot of the first optical signal, and the second optical signal is irradiated on the grating array of the OPA. And combining the at least one waveguide optical wave of the grating array and the phase modulator array to form a combined optical signal after performing superposition processing on the optical coupler. When the second optical signal is irradiated on the grating array, the grating signal can detect the optical signal by the partial grating, and the grating illuminated by the optical signal couples the detected optical signal into the waveguide optical wave, and the waveguide optical wave is input to the corresponding phase modulator. The optical coupler is coupled; the grating without the illumination of the optical signal does not generate the waveguide light wave; at this time, the phase modulator does not perform the phase modulation operation on the waveguide light wave.
对低通滤波处理得到的低频噪声电信号进行采样处理,具体使用模数转换
器根据预设的采样周期获取至少一个采样值(例如采样值的数量大于10个),对至少一个采样值计算其方差。Sampling low-frequency noise electrical signals obtained by low-pass filtering, specifically using analog-to-digital conversion
The device acquires at least one sample value according to a preset sampling period (for example, the number of sample values is greater than 10), and calculates a variance of the at least one sample value.
S704、方差是否大于方差阈值。S704, whether the variance is greater than a variance threshold.
判断计算得到的方差是否大于预设的方差阈值值,若为是,执行S705,否则执行S706。It is judged whether the calculated variance is greater than a preset variance threshold value, and if so, S705 is performed, otherwise S706 is performed.
S705、根据光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量。S705. Determine a phase modulator to be adjusted according to position information of the spot, and calculate a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm.
具体的,根据CCD采集的光斑的位置信息确定待调节的相位调制器,待调节的相位调制器即第二光信号照射的部分光栅对应的相位调制器,处理器根据预设的自适应算法为待调节的相位调制器生成一个电压调节量,电压调节量分为正电压调节量和负电压调节量,正电压调节量用于增加相位调制器上的承载电压,负电压调节量用于减少相位调制器上的承载电压。Specifically, the phase modulator to be adjusted is determined according to the position information of the spot collected by the CCD, and the phase modulator to be adjusted, that is, the phase modulator corresponding to the partial grating irradiated by the second light signal, is processed by the processor according to a preset adaptive algorithm. The phase modulator to be adjusted generates a voltage adjustment amount, the voltage adjustment amount is divided into a positive voltage adjustment amount and a negative voltage adjustment amount, the positive voltage adjustment amount is used to increase the load voltage on the phase modulator, and the negative voltage adjustment amount is used to reduce the phase The carrying voltage on the modulator.
S706、结束。S706, the end.
具体的,如果计算得到的方差小于预设的方差阈值,表明大气湍流噪声可以被忽略,不需要进行相位控制。Specifically, if the calculated variance is less than the preset variance threshold, it indicates that atmospheric turbulence noise can be ignored and phase control is not required.
S707、根据所述电压调节量调节所述待调节的相位调制器的承载电压。S707. Adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
具体的,相位调制器阵列中的相位调制器按照顺序进行排列,待调节的相位调制器可以采用位图的方式表示相位调制器阵列中的位置,例如:Address(1,0,1,1,……,1,1),1表示需要进行相位调节的相位调制器,0表示不需要进行相位调节的相位调制器,Voltage(U1,U2,……,Un),U1表示第1个相位调制器上的电压调节量,Un表示第n个相位调制器的电压调节量,Un可以用正负值来表示正电压调节量和负电压调节量。根据所述地址确定需要待调节的相位调制器,以及根据所述电压调节量调节所述相位调制器的承载电压,从而改变经过待调节的相位调制器的的波导光波的相位,使光耦合器输入的波导光波的相位均相同,即使光耦合器输入的波导光波具备相干性,光耦合器对相位相同的波导光波进行相干叠加处理生成合路光信号。Specifically, the phase modulators in the phase modulator array are arranged in sequence, and the phase modulator to be adjusted can represent the position in the phase modulator array in a bitmap manner, for example: Address (1, 0, 1, 1, ..., 1,1), 1 indicates a phase modulator that requires phase adjustment, 0 indicates a phase modulator that does not require phase adjustment, Voltage (U1, U2, ..., Un), U1 indicates the first phase modulation The voltage adjustment amount on the device, Un represents the voltage adjustment amount of the nth phase modulator, and Un can use the positive and negative values to indicate the positive voltage adjustment amount and the negative voltage adjustment amount. Determining, according to the address, a phase modulator that needs to be adjusted, and adjusting a carrier voltage of the phase modulator according to the voltage adjustment amount, thereby changing a phase of a waveguide light wave passing through a phase modulator to be adjusted, so that the optical coupler The phase of the input waveguide light wave is the same, and even if the waveguide light wave input from the optical coupler has coherence, the optical coupler coherently superimposes the waveguide light waves of the same phase to generate a combined optical signal.
延迟预设时长后,重复执行S701,将相位调节后的合路光信号转换为电信号,对电信号进行采样处理得到至少一个采样值,处理器计算至少一个采样值的方差,若计算得到的方差仍然大于方差阈值,继续对OPA的相位调制器
进行相位调节操作,直到计算得到的方差小于方差阈值,退出循环。After delaying the preset duration, S701 is repeatedly executed to convert the phase-adjusted combined optical signal into an electrical signal, and the electrical signal is sampled to obtain at least one sampled value, and the processor calculates a variance of at least one sampled value, if the calculated The variance is still greater than the variance threshold and continues to the phase modulator of the OPA
Perform a phase adjustment operation until the calculated variance is less than the variance threshold and exit the loop.
可选的,所述根据所述光斑的位置信息确定待调节的相位调制器包括:Optionally, the determining, according to the location information of the spot, the phase modulator to be adjusted includes:
计算出所述光斑在所述CCD上的像素分布区域;Calculating a pixel distribution area of the spot on the CCD;
查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。Querying at least one grating associated with the pixel distribution region and determining the phase modulator to be adjusted associated with the at least one grating based on a mapping relationship between the grating and the phase modulator.
可选的,所述对所述电信号进行低通滤波处理后生成低频噪声电信号之前,还包括:Optionally, before performing the low-pass filtering process on the electrical signal to generate the low-frequency noise electrical signal, the method further includes:
对所述电信号进行放大处理。The electrical signal is amplified.
可选的所述根据光学自适应算法计算所述待调节的相位调制器的电压调节量包括:Optionally, calculating the voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm includes:
根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。The voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
本发明实施例和光接收机的实施例基于同一构思,其带来的技术效果也相同,具体请参照实施例一的描述,此处不再赘述。The embodiments of the present invention and the embodiment of the optical receiver are based on the same concept, and the technical effects thereof are also the same. For details, refer to the description of the first embodiment, and details are not described herein again.
实施本发明的实施例,对OPA输出的光信号进行光电转换、低通滤波处理得到低频噪声电信号,通过计算低频噪声电信号的采样值的方差,如果方差大于方差阈值,通过CCD获取待调节的相位调制器的地址,对带调节的相位调制器的承载电压进行调节,避免对所有的相位控制器进行调节,减少了计算量。Embodiments of the present invention perform photoelectric conversion and low-pass filtering processing on an optical signal output by the OPA to obtain a low-frequency noise electrical signal, and calculate a variance of a sampled value of the low-frequency noise electrical signal. If the variance is greater than a variance threshold, the CCD acquires a to-be-adjusted The address of the phase modulator adjusts the load voltage of the phase modulator with adjustment to avoid adjustment of all phase controllers, reducing the amount of calculation.
参见图8,为本发明实施例提供的一种光接收机的另一结构示意图,在本发明实施例中,所述光接收机包括:光学天线80、分光器81、电荷耦合元件CCD88、光学相控阵列OPA82、光电转换模块83、低通滤波模块84、方差计算模块85、相控参数生成模块86和电压调节模块87,所述OPA82包括光栅阵列、相位调制器阵列和光耦合器,其中,FIG. 8 is another schematic structural diagram of an optical receiver according to an embodiment of the present invention. In the embodiment of the present invention, the optical receiver includes: an optical antenna 80, a beam splitter 81, a charge coupled component CCD88, and optical The phased array OPA82, the photoelectric conversion module 83, the low pass filtering module 84, the variance calculation module 85, the phase control parameter generation module 86, and the voltage adjustment module 87, the OPA 82 includes a grating array, a phase modulator array, and an optical coupler, wherein
所述光学天线80用于对接收的光信号进行汇聚处理后生成汇聚光信号;The optical antenna 80 is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal.
所述分光器81用于对所述汇聚光信号进行分路处理后生成第一光信号和第二光信号;The beam splitter 81 is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal.
所述CCD88用于采集所述第一光信号的光斑;
The CCD 88 is configured to collect a spot of the first optical signal;
所述OPA82用于通过所述光栅阵列接收所述第二光信号,并将经由所述光栅阵列和所述相位调制器阵列的波导光波由所述光耦合器处理后生成合路光信号;The OPA 82 is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;
光电转换模块83,用于对所述合路光信号进行光电转换处理后生成电信号;The photoelectric conversion module 83 is configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal;
低通滤波模块84,用于对所述电信号进行低通滤波处理后生成低频噪声电信号;a low pass filtering module 84, configured to perform low pass filtering on the electrical signal to generate a low frequency noise electrical signal;
方差计算模块85,用于对所述低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差;The variance calculation module 85 is configured to perform sampling processing on the low frequency noise electrical signal to obtain at least one sampled value, and calculate a variance of the at least one sampled value;
相控参数生成模块86,用于若所述方差大于方差阈值,根据所述光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量;The phase control parameter generating module 86 is configured to determine, according to the position information of the spot, a phase modulator to be adjusted, and calculate a voltage adjustment of the phase modulator to be adjusted according to an optical adaptive algorithm, if the variance is greater than a variance threshold the amount;
电压调节模块88,用于根据所述电压调节量调节所述待调节的相位调制器的承载电压。The voltage adjustment module 88 is configured to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
可选的,所述相控参数生成模块包括:Optionally, the phase control parameter generating module includes:
计算单元,用于计算出所述光斑在所述CCD上的像素分布区域;a calculating unit, configured to calculate a pixel distribution area of the spot on the CCD;
查询单元,用于查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。And a query unit, configured to query at least one grating associated with the pixel distribution area, and determine the phase modulator to be adjusted associated with the at least one grating according to a mapping relationship between the grating and the phase modulator.
可选的,所述光学天线、分光器和所述OPA的光栅阵列共光轴,所述分光器与所述光轴成45°角,所述光学天线的焦平面到所述分光器的中心点的距离为L1,所述CCD的中心点到所述分光器的中心点的连线垂直于所述光轴,所述CCD的中心点到所述分光器的中心点的距离为L2,其中,L1=L2。可选的,所述光栅阵列位于所述光学天线的焦平面的前方,所述光栅阵列的最小直径为DOPA,所述CCD的最小直径为DCCD,则Optionally, the optical antenna, the optical splitter and the grating array of the OPA share an optical axis, the optical splitter is at an angle of 45° to the optical axis, and a focal plane of the optical antenna is to a center of the optical splitter The distance of the point is L1, the line connecting the center point of the CCD to the center point of the beam splitter is perpendicular to the optical axis, and the distance from the center point of the CCD to the center point of the beam splitter is L2, wherein , L1 = L2. Optionally, the grating array is located in front of a focal plane of the optical antenna, the minimum diameter of the grating array is D OPA , and the minimum diameter of the CCD is D CCD , then
DOPA=2(F0-△L)*tanθ+(Dr/F0)*△L;D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;
DCCD=2F0*tanθ;D CCD = 2F 0* tan θ;
其中,F0为所述光学天线的焦距,△L为所述光栅阵列与所述光学天线的焦平面之间的距离,θ为所述汇聚光信号与所述光轴的之间的最大偏转角度,Dr为所述光学天线的直径。
Wherein F 0 is the focal length of the optical antenna, ΔL is the distance between the grating array and the focal plane of the optical antenna, and θ is the maximum deflection between the concentrated optical signal and the optical axis Angle, D r is the diameter of the optical antenna.
可选的,所述光接收机还包括:放大模块,用于对所述光电转换模块生成的所述电信号进行放大处理,并将放大处理后的电信号发送至所述低通滤波模块。Optionally, the optical receiver further includes: an amplifying module, configured to perform amplification processing on the electrical signal generated by the photoelectric conversion module, and send the amplified electrical signal to the low-pass filtering module.
可选的,所述相控参数生成模块用于根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。Optionally, the phase control parameter generating module is configured to calculate a voltage adjustment amount of the phase controller to be adjusted according to a random parallel gradient algorithm; wherein, the voltage adjustment of each phase controller in the phase controller to be adjusted The amount is consistent with the Bernoulli distribution.
本发明实施例和基于光接收机的光信号调节方法基于同一构思,用于实现光信号调节方法,其带来的技术效果也相同,具体请参照实施例一和二的描述,此处不再赘述。The embodiment of the present invention and the optical signal adjustment method based on the optical receiver are based on the same concept and are used to implement the optical signal adjustment method, and the technical effects thereof are also the same. For details, refer to the descriptions of Embodiments 1 and 2, and no longer Narration.
本领域普通技术人员可以理解实现上述实施例方法中的全部或部分流程,是可以通过计算机程序来指令相关的硬件来完成,所述的程序可存储于一计算机可读取存储介质中,该程序在执行时,可包括如上述各方法的实施例的流程。其中,所述的存储介质可为磁碟、光盘、只读存储记忆体(Read-Only Memory,ROM)或随机存储记忆体(Random Access Memory,RAM)等。One of ordinary skill in the art can understand that all or part of the process of implementing the foregoing embodiments can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).
以上所揭露的仅为本发明一种较佳实施例而已,当然不能以此来限定本发明之权利范围,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流程,并依本发明权利要求所作的等同变化,仍属于发明所涵盖的范围。
The above disclosure is only a preferred embodiment of the present invention, and of course, the scope of the present invention is not limited thereto, and those skilled in the art can understand all or part of the process of implementing the above embodiments, and according to the present invention. The equivalent changes required are still within the scope of the invention.
Claims (16)
- 一种光接收机,其特征在于,包括:光学天线、分光器、电荷耦合元件CCD、光电探测器、驱动器、光学相控阵列OPA、低通滤波器和处理器;其中,所述OPA包括光栅阵列、相位调制器阵列和光耦合器;An optical receiver, comprising: an optical antenna, a beam splitter, a charge coupled device CCD, a photodetector, a driver, an optical phased array OPA, a low pass filter, and a processor; wherein the OPA includes a grating Arrays, phase modulator arrays, and optocouplers;所述光学天线用于对接收的光信号进行汇聚处理后生成汇聚光信号;The optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal;所述分光器用于对所述汇聚光信号进行分路处理后生成第一光信号和第二光信号;The beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;所述CCD用于采集所述第一光信号的光斑;The CCD is configured to collect a spot of the first optical signal;所述OPA用于通过所述光栅阵列接收所述第二光信号,并将经由所述光栅阵列和所述相位调制器阵列的波导光波由所述光耦合器处理后生成合路光信号;The OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;所述光电探测器用于对所述合路光信号进行光电转换处理后生成电信号;The photodetector is configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal;所述低通滤波器用于对所述电信号进行低通滤波处理后生成低频噪声电信号;The low pass filter is configured to perform low pass filtering processing on the electrical signal to generate a low frequency noise electrical signal;所述处理器用于对所述低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差;The processor is configured to perform sampling processing on the low frequency noise electrical signal to obtain at least one sample value, and calculate a variance of the at least one sample value;若所述方差大于方差阈值,根据所述光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量;If the variance is greater than a variance threshold, determining a phase modulator to be adjusted according to the position information of the spot, and calculating a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm;所述处理器向所述驱动器发送相位调节指示消息,所述相位调节指示消息用于指示所述驱动器根据所述电压调节量调节所述待调节的相位调制器的承载电压。The processor sends a phase adjustment indication message to the driver, the phase adjustment indication message is used to instruct the driver to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
- 如权利要求1所述的光接收机,其特征在于,所述根据所述光斑的位置信息确定待调节的相位调制器包括:The optical receiver according to claim 1, wherein the determining the phase modulator to be adjusted according to the position information of the spot comprises:计算出所述光斑在所述CCD上的像素分布区域;Calculating a pixel distribution area of the spot on the CCD;查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。 Querying at least one grating associated with the pixel distribution region and determining the phase modulator to be adjusted associated with the at least one grating based on a mapping relationship between the grating and the phase modulator.
- 如权利要求1或2所述的光接收机,其特征在于,所述光学天线、分光器和所述OPA的光栅阵列共光轴,所述分光器与所述光轴成45°角,所述光学天线的焦平面到所述分光器的中心点的距离为L1,所述CCD的中心点到所述分光器的中心点的连线垂直于所述光轴,所述CCD的中心点到所述分光器的中心点的距离为L2,其中,L1=L2。The optical receiver according to claim 1 or 2, wherein said optical antenna, the optical splitter and said grating array of said OPA share an optical axis, said optical splitter being at an angle of 45 with said optical axis, a distance from a focal plane of the optical antenna to a center point of the beam splitter is L1, a line connecting a center point of the CCD to a center point of the beam splitter is perpendicular to the optical axis, and a center point of the CCD is The distance from the center point of the beam splitter is L2, where L1 = L2.
- 如权利要求3所述的光接收机,其特征在于,所述光栅阵列位于所述光学天线的焦平面的前方,所述光栅阵列的最小直径为DOPA,所述CCD的最小直径为DCCD,则The optical receiver according to claim 3, wherein said grating array is located in front of a focal plane of said optical antenna, said grating array has a minimum diameter of D OPA , and said CCD has a minimum diameter of D CCD ,thenDOPA=2(F0-△L)*tanθ+(Dr/F0)*△L;D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;DCCD=2F0*tanθ;D CCD = 2F 0 * tanθ;其中,F0为所述光学天线的焦距,△L为所述光栅阵列与所述光学天线的焦平面之间的距离,θ为所述汇聚光信号与所述光轴的之间的最大偏转角度,Dr为所述光学天线的直径。Wherein F 0 is the focal length of the optical antenna, ΔL is the distance between the grating array and the focal plane of the optical antenna, and θ is the maximum deflection between the concentrated optical signal and the optical axis Angle, D r is the diameter of the optical antenna.
- 如权利要求1-4任意一项所述的光接收机,其特征在于,还包括:放大器,所述放大器连接在所述光电探测器和所述低通滤波器之间,所述放大器用于对所述光电探测器生成的所述电信号进行放大处理,并将放大处理后的电信号发送至所述低通滤波器。An optical receiver according to any one of claims 1 to 4, further comprising: an amplifier connected between said photodetector and said low pass filter, said amplifier being used for And amplifying the electrical signal generated by the photodetector, and transmitting the amplified electrical signal to the low pass filter.
- 如权利要求1-5任意一项所述的光接收机,其特征在于,所述根据光学自适应算法计算所述待调节的相位调制器的电压调节量包括:The optical receiver according to any one of claims 1 to 5, wherein the calculating the voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm comprises:根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。The voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
- 一种基于光接收机的光信号调节方法,其特征在于,所述光接收机包括:光学天线、分光器、电荷耦合元件CCD、光学相控阵列OPA;其中,所述OPA包括光栅阵列、相位调制器阵列和光耦合器;An optical receiver-based optical signal adjustment method, characterized in that the optical receiver comprises: an optical antenna, a beam splitter, a charge coupled device CCD, an optical phased array OPA; wherein the OPA comprises a grating array and a phase a modulator array and an optical coupler;所述光学天线用于对接收的光信号进行汇聚处理后生成汇聚光信号; The optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal;所述分光器用于对所述汇聚光信号进行分路处理后生成第一光信号和第二光信号;The beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;所述CCD用于采集所述第一光信号的光斑;The CCD is configured to collect a spot of the first optical signal;所述OPA用于通过所述光栅阵列接收所述第二光信号,并将经由所述光栅阵列和所述相位调制器阵列的波导光波由所述光耦合器处理后生成合路光信号;The OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;所述光信号调节方法包括:The optical signal adjustment method includes:对所述合路光信号进行光电转换处理后生成电信号;Performing photoelectric conversion processing on the combined optical signal to generate an electrical signal;对所述电信号进行低通滤波处理后生成低频噪声电信号;Performing low-pass filtering on the electrical signal to generate a low-frequency noise electrical signal;对所述低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差;Performing sampling processing on the low frequency noise electrical signal to obtain at least one sampled value, and calculating a variance of the at least one sampled value;若所述方差大于方差阈值,根据所述光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量;If the variance is greater than a variance threshold, determining a phase modulator to be adjusted according to the position information of the spot, and calculating a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm;根据所述电压调节量调节所述待调节的相位调制器的承载电压。The carrying voltage of the phase modulator to be adjusted is adjusted according to the voltage regulation amount.
- 如权利要求7所述的方法,其特征在于,所述根据所述光斑的位置信息确定待调节的相位调制器包括:The method according to claim 7, wherein the determining the phase modulator to be adjusted according to the position information of the spot comprises:计算出所述光斑在所述CCD上的像素分布区域;Calculating a pixel distribution area of the spot on the CCD;查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。Querying at least one grating associated with the pixel distribution region and determining the phase modulator to be adjusted associated with the at least one grating based on a mapping relationship between the grating and the phase modulator.
- 如权利要求7或8所述的方法,其特征在于,所述对所述电信号进行低通滤波处理后生成低频噪声电信号之前,还包括:The method according to claim 7 or 8, wherein before the low-pass filtering process is performed on the electrical signal to generate a low-frequency noise electrical signal, the method further includes:对所述电信号进行放大处理。The electrical signal is amplified.
- 如权利要求7-9任意一项所述的方法,其特征在于,所述根据光学自适应算法计算所述待调节的相位调制器的电压调节量包括:The method according to any one of claims 7 to 9, wherein the calculating the voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm comprises:根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。 The voltage adjustment amount of the phase controller to be adjusted is calculated according to a random parallel gradient algorithm; wherein the voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to a Bernoulli distribution.
- 一种光接收机,其特征在于,包括:光学天线、分光器、电荷耦合元件CCD、光学相控阵列OPA、光电转换模块、低通滤波模块、方差计算模块、相控参数生成模块和电压调节模块,所述OPA包括光栅阵列、相位调制器阵列和光耦合器,其中,An optical receiver, comprising: an optical antenna, a beam splitter, a charge coupled device CCD, an optical phased array OPA, a photoelectric conversion module, a low pass filter module, a variance calculation module, a phase control parameter generation module, and a voltage adjustment a module, the OPA comprising a grating array, a phase modulator array, and an optocoupler, wherein所述光学天线用于对接收的光信号进行汇聚处理后生成汇聚光信号;The optical antenna is configured to perform a convergence process on the received optical signal to generate a concentrated optical signal;所述分光器用于对所述汇聚光信号进行分路处理后生成第一光信号和第二光信号;The beam splitter is configured to generate a first optical signal and a second optical signal after performing the shunt processing on the concentrated optical signal;所述CCD用于采集所述第一光信号的光斑;The CCD is configured to collect a spot of the first optical signal;所述OPA用于通过所述光栅阵列接收所述第二光信号,并将经由所述光栅阵列和所述相位调制器阵列的波导光波由所述光耦合器处理后生成合路光信号;The OPA is configured to receive the second optical signal through the grating array, and process a waveguide optical wave passing through the grating array and the phase modulator array by the optical coupler to generate a combined optical signal;光电转换模块,用于对所述合路光信号进行光电转换处理后生成电信号;a photoelectric conversion module, configured to perform photoelectric conversion processing on the combined optical signal to generate an electrical signal;低通滤波模块,用于对所述电信号进行低通滤波处理后生成低频噪声电信号;a low pass filtering module, configured to perform low pass filtering on the electrical signal to generate a low frequency noise electrical signal;方差计算模块,用于对所述低频噪声电信号进行采样处理后得到至少一个采样值,并计算所述至少一个采样值的方差;a variance calculation module, configured to perform sampling processing on the low-frequency noise electrical signal to obtain at least one sampled value, and calculate a variance of the at least one sampled value;相控参数生成模块,用于若所述方差大于方差阈值,根据所述光斑的位置信息确定待调节的相位调制器,以及根据光学自适应算法计算所述待调节的相位调制器的电压调节量;a phase control parameter generating module, configured to determine a phase modulator to be adjusted according to position information of the spot if the variance is greater than a variance threshold, and calculate a voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm ;电压调节模块,用于根据所述电压调节量调节所述待调节的相位调制器的承载电压。And a voltage adjustment module, configured to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
- 如权利要求11所述的光接收机,其特征在于,所述相控参数生成模块包括:The optical receiver of claim 11, wherein the phased parameter generation module comprises:计算单元,用于计算出所述光斑在所述CCD上的像素分布区域;a calculating unit, configured to calculate a pixel distribution area of the spot on the CCD;查询单元,用于查询与所述像素分布区域关联的至少一个光栅,以及根据光栅与相位调制器的映射关系确定所述至少一个光栅关联的所述待调节的相位调制器。And a query unit, configured to query at least one grating associated with the pixel distribution area, and determine the phase modulator to be adjusted associated with the at least one grating according to a mapping relationship between the grating and the phase modulator.
- 如权利要求11或12所述的光接收机,其特征在于,所述光学天线、 分光器和所述OPA的光栅阵列共光轴,所述分光器与所述光轴成45°角,所述光学天线的焦平面到所述分光器的中心点的距离为L1,所述CCD的中心点到所述分光器的中心点的连线垂直于所述光轴,所述CCD的中心点到所述分光器的中心点的距离为L2,其中,L1=L2。The optical receiver according to claim 11 or 12, wherein said optical antenna, a beam splitter and a grating array of the OPA sharing an optical axis, the beam splitter being at an angle of 45° to the optical axis, a distance from a focal plane of the optical antenna to a center point of the beam splitter being L1, the CCD The line connecting the center point to the center point of the beam splitter is perpendicular to the optical axis, and the distance from the center point of the CCD to the center point of the beam splitter is L2, where L1 = L2.
- 如权利要求13所述的光接收机,其特征在于,所述光栅阵列位于所述光学天线的焦平面的前方,所述光栅阵列的最小直径为DOPA,所述CCD的最小直径为DCCD,则The optical receiver according to claim 13, wherein said grating array is located in front of a focal plane of said optical antenna, said grating array has a minimum diameter of D OPA , and said CCD has a minimum diameter of D CCD ,thenDOPA=2(F0-△L)*tanθ+(Dr/F0)*△L;D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;DCCD=2F0*tanθ;D CCD = 2F 0 * tan θ;其中,F0为所述光学天线的焦距,△L为所述光栅阵列与所述光学天线的焦平面之间的距离,θ为所述汇聚光信号与所述光轴的之间的最大偏转角度,Dr为所述光学天线的直径。Wherein F 0 is the focal length of the optical antenna, ΔL is the distance between the grating array and the focal plane of the optical antenna, and θ is the maximum deflection between the concentrated optical signal and the optical axis Angle, D r is the diameter of the optical antenna.
- 如权利要求11-14任意一项所述的光接收机,其特征在于,还包括:The optical receiver according to any one of claims 11 to 14, further comprising:放大模块,用于对所述光电转换模块生成的所述电信号进行放大处理,并将放大处理后的电信号发送至所述低通滤波模块。And an amplification module, configured to perform amplification processing on the electrical signal generated by the photoelectric conversion module, and send the amplified electrical signal to the low-pass filter module.
- 如权利要求11-15任意一项所述的光接收机,其特征在于,所述相控参数生成模块用于根据随机并行梯度算法计算所述待调节的相位控制器的电压调节量;其中,所述待调节的相位控制器中各个相位控制器的电压调节量符合伯努利分布。 The optical receiver according to any one of claims 11 to 15, wherein the phase control parameter generating module is configured to calculate a voltage adjustment amount of the phase controller to be adjusted according to a random parallel gradient algorithm; The voltage adjustment amount of each phase controller in the phase controller to be adjusted conforms to the Bernoulli distribution.
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