WO2016187826A1

WO2016187826A1 - Optical receiver and optical receiver-based optical signal adjustment method

Info

Publication number: WO2016187826A1
Application number: PCT/CN2015/079857
Authority: WO
Inventors: 赵平; 石晓钟; 吴波; 邱少锋
Original assignee: 华为技术有限公司
Priority date: 2015-05-26
Filing date: 2015-05-26
Publication date: 2016-12-01
Also published as: CN107615725A; CN107615725B

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

Optical receiver and optical signal adjusting method based on optical receiver

Technical field

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.

Background technique

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.

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.

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.

Summary of the invention

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.

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;

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;

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;

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.

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:

Calculating a pixel distribution area of the spot on the CCD;

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.

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.

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

D _OPA = 2 (F ₀ - ΔL) * tan θ + (D _r / F ₀ ) * ΔL;

D _CCD = 2F _0* tan θ;

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.

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.

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:

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 CCD is configured to collect a spot of the first optical signal;

The optical signal adjustment method includes:

Performing photoelectric conversion processing on the combined optical signal to generate an electrical signal;

Performing low-pass filtering on the electrical signal to generate a low-frequency noise electrical signal;

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;

The carrying voltage of the phase modulator to be adjusted is adjusted according to the voltage regulation amount.

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:

Calculating a pixel distribution area of the spot on the CCD;

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.

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:

The electrical signal is amplified.

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:

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

The CCD is configured to collect a spot of the first 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;

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 ;

And a voltage adjustment module, configured to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.

In conjunction with the third aspect, in a first possible implementation, the phase control parameter generating module includes:

a calculating unit, configured to calculate a pixel distribution area of the spot on the CCD;

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.

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.

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

D _OPA = 2 (F ₀ - ΔL) * tan θ + (D _r / F ₀ ) * ΔL;

D _CCD = 2F _0* tan θ;

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:

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.

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.

The implementation of the present invention has the following beneficial effects:

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.

DRAWINGS

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.

1 is a schematic structural diagram of an optical receiver according to an embodiment of the present invention;

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.

FIG. 8 is another schematic structural diagram of an optical receiver according to an embodiment of the present invention.

detailed description

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.

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.

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.

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 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.

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.

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.

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.

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.

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.

Optionally, the determining, according to the location information of the spot, the phase modulator to be adjusted includes:

Calculating a pixel distribution area of the spot on the CCD;

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.

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.

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.

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.

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.

Specifically, the photodetector 12 can be a photoelectric avalanche diode, and the amplifier can be a transconductance amplifier.

Optionally, the calculating, according to an algorithm optical adaptive algorithm, the power of the phase modulator to be adjusted The pressure adjustment amount 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.

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.

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

D _OPA = 2 (F ₀ - ΔL) * tan θ + (D _r / F ₀ ) * ΔL;

D _CCD = 2F _0* tan θ;

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.

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:

D _OPA =2(F ₀ -△L)*tanθ+(D _r /F ₀ )*△L

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.

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.

Table 1

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.

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.

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. Perform photoelectric conversion processing on the combined optical signal output by the optical coupler to generate an electrical signal.

S702. Perform low-pass filtering processing on the electrical signal to generate a low-frequency noise electrical signal.

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. 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.

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.

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.

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, whether the variance is greater than a variance threshold.

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. 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.

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, the end.

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. Adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.

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.

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.

Calculating a pixel distribution area of the spot on the CCD;

Optionally, 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.

Optionally, calculating the voltage adjustment amount of the phase modulator to be adjusted according to an optical adaptive algorithm includes:

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.

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. 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

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.

Optionally, the phase control parameter generating module includes:

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

D _OPA = 2 (F ₀ - ΔL) * tan θ + (D _r / F ₀ ) * ΔL;

D _CCD = 2F _0* tan θ;

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.

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.

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.

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).

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

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;

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;

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;

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.
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:

Calculating a pixel distribution area of the spot on the CCD;

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.
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.
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 ,then

D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;

D CCD = 2F 0 * tanθ;

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.
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.
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:

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.
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;

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:

Performing photoelectric conversion processing on the combined optical signal to generate an electrical signal;

Performing low-pass filtering on the electrical signal to generate a low-frequency noise electrical signal;

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;

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;

The carrying voltage of the phase modulator to be adjusted is adjusted according to the voltage regulation amount.
The method according to claim 7, wherein the determining the phase modulator to be adjusted according to the position information of the spot comprises:

Calculating a pixel distribution area of the spot on the CCD;

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.
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:

The electrical signal is amplified.
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:

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.
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

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;

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 ;

And a voltage adjustment module, configured to adjust a load voltage of the phase modulator to be adjusted according to the voltage adjustment amount.
The optical receiver of claim 11, wherein the phased parameter generation module comprises:

a calculating unit, configured to calculate a pixel distribution area of the spot on the CCD;

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.
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.
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 ,then

D OPA = 2 (F 0 - ΔL) * tan θ + (D r / F 0 ) * ΔL;

D CCD = 2F 0 * tan θ;

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.
The optical receiver according to any one of claims 11 to 14, further comprising:

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.
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.