阅读说明：本技术 光子干涉成像系统内部误差标定补偿系统及标定补偿方法 (Internal error calibration compensation system and calibration compensation method for photon interference imaging system ) 是由 张怡 王越 刘欣悦 孟浩然 刘欣然 樊元朋 于 2019-09-26 设计创作，主要内容包括：光子干涉成像系统内部误差标定补偿系统及标定补偿方法,涉及光干涉成像技术领域,解决现有干涉成像系统的器件内部存在各种误差,进而影响成像系统的性能等问题,包括标定光源、相位调节装置、待测PIC芯片、光强检测装置以及光纤耦合器；光纤耦合器的一端与标定光源连接,所述标定光源分为两路输出,光纤耦合器另一端的两个输出端口各与一个相位调节装置的输入口连接,两个相位调节装置的输出口分别与待测PIC芯片的两个输入端口连接；光强检测装置置于待测PIC芯片后端,用于检测PIC芯片四个输出端口的输出光强。本发明对于PIC集成芯片内部误差,通过建立误差标定补偿模型,对内部误差进行有效的校正,使系统能达到较好的成像效果。简化系统操作。(An internal error calibration compensation system and a calibration compensation method of a photon interference imaging system relate to the technical field of optical interference imaging, and solve the problems that various errors exist in the device of the existing interference imaging system, and the performance of the imaging system is further influenced, and the like, and comprise a calibration light source, a phase adjusting device, a PIC chip to be detected, a light intensity detection device and an optical fiber coupler; one end of the optical fiber coupler is connected with a calibration light source, the calibration light source is divided into two paths of output, two output ports at the other end of the optical fiber coupler are respectively connected with an input port of one phase adjusting device, and output ports of the two phase adjusting devices are respectively connected with two input ports of a PIC chip to be tested; the light intensity detection device is arranged at the rear end of the PIC chip to be detected and is used for detecting the output light intensity of four output ports of the PIC chip. The invention effectively corrects the internal error of the PIC integrated chip by establishing an error calibration compensation model, so that the system can achieve better imaging effect. Simplifying the system operation.)

1. The internal error calibration compensation system of the photon interference imaging system comprises a calibration light source, a phase adjusting device, a PIC chip to be detected, a light intensity detection device and an optical fiber coupler; the method is characterized in that:

one end of the optical fiber coupler is connected with a calibration light source, the calibration light source is divided into two paths of output, two output ports at the other end of the optical fiber coupler are respectively connected with an input port of one phase adjusting device, and output ports of the two phase adjusting devices are respectively connected with two input ports of a PIC chip to be tested; the light intensity detection device is arranged at the rear end of the PIC chip to be detected and is used for detecting the output light intensity of four output ports of the PIC chip.

2. The internal error calibration compensation device of photon interference imaging system according to claim 1, wherein: the PIC chip to be tested is provided with two input ports and four output ports, a group of interferometers is arranged in the PIC chip to be tested, and each interferometer consists of a pair of waveguides and a beam combiner.

3. The system of claim 1, wherein the system comprises: the light intensity detection device is a photoelectric detector.

4. The calibration compensation method of the internal error calibration compensation system of the photon interference imaging system as claimed in claim 1, wherein: the method is realized by the following steps:

step one, establishing an input/output model of a PIC chip to be tested;

in the formula, N₁And N₂In order to calibrate the input light intensity of the light source,

turning on a calibration light source for calibration; adjusting the electronic delay line of the phase adjusting device to make the phase difference of the two interference channels be 0 to ensure that

in the formula (I), the compound is shown in the specification,

thirdly, cutting off optical signals input by the input port 2 of the PIC chip to be detected, detecting output signals of four output ports of the PIC chip to be detected by adopting a light intensity detection device, and recording output light intensities of the four output ports; at this time, N₁＞0，N₂0, according to the recorded output light intensity of the output port of the PIC chip to be tested

Step four, cutting off the optical signal input by the input port 1 of the PIC chip to be detected, and detecting four outputs of the PIC chip to be detected through the light intensity detection deviceOutputting the output signal of the output port, and recording the output light intensity of the four output ports; at this time, N₁＝0，N₂If more than 0, according to the recorded output light intensity of the output port of the PIC chip to be tested

Step five, input optical signals of two input ports of the PIC chip to be detected are kept, output signals of four output ports of the PIC chip to be detected are detected through a light intensity detection device, and output light intensities of the four output ports are recorded; at this time, N₁＞0，N₂If more than 0, according to the recorded output light intensity of the output port of the PIC chip to be tested

Step six, adjusting the phase of one phase adjusting device to change the phase by pi/2, at the moment,obtaining the following matrix form of the input and output model of the PIC chip to be tested;

in the formula (I), the compound is shown in the specification,

step seven, input optical signals of two input ports of the PIC chip to be detected are kept, output signals of four output ports of the PIC chip to be detected are detected through a light intensity detection device, and output light intensities of the four output ports are recorded; at this time, N₁＞0,N₂If more than 0, according to the recorded output light intensity of the output port of the PIC chip to be tested

Step eight, obtaining according to step three, step four, step five and step seven

in the formula (I), the compound is shown in the specification,is a target characteristic parameter;characteristic parameters of PIC integrated chip devices;

adjusting the light intensity of a calibration light source as a target to be detected, enabling input light signals of two input ports of the PIC chip to be detected, detecting output signals of four output ports of the PIC chip to be detected through a light intensity detection device, and recording output light intensities of the four output ports; according to the recorded output light intensity of the output port of the PIC chip to be tested

Technical Field

The invention relates to the technical field of optical interference imaging, in particular to an internal error calibration compensation system and a calibration compensation method of a photon interference imaging system.

Background

The core of photonic integrated interference imaging is a PIC photonic integrated chip. The PIC photonic integrated chip adopts the integrated optical technology, so that the device can keep reliability and stability under the condition of greatly reducing the volume, and the performance of the device is integrally improved. The device has a complex internal structure and comprises a plurality of structural units. Therefore, the PIC photonic integrated chip is prone to generate errors in the manufacturing process, and once the chip is packaged and manufactured, the errors cannot be eliminated through a hardware correction method. Therefore, a method for learning the internal error of the photonic integrated chip and compensating the internal error of the chip based on the internal error is needed.

The resolution of the traditional telescope is in direct proportion to the caliber, but the improvement of the resolution is limited due to the technical cost and the like along with the increase of the caliber. The synthetic aperture telescope adopting the interference technology can realize a very large equivalent aperture by adopting the long baseline, and ensures enough resolution. But the imaging speed is low due to the small number of baselines, and the requirement on the target is high. The photonic integration interference imaging technology breaks through the limitation on the scale of the sub-aperture array, greatly increases the baseline configuration, solves the problem of insufficient spectrum coverage rate of the traditional optical synthetic aperture technology, effectively reduces the volume, weight and processing difficulty of the system, and finally realizes the real-time, high-resolution, multi-spectrum and large-view-field imaging system.

According to the Van-Zernike theorem, the photon integration interference imaging technology is to simultaneously sample a target through a plurality of Michelson interference channels integrated on a PIC chip to obtain frequency spectrum information of the target, and then to obtain light intensity information of the target after Fourier inverse transformation. In practical operation, the spectral distribution of the target can be obtained by measuring the complex coherence of the target, thereby obtaining the light intensity distribution of the target. For the complex coherence of the target, the mode and the phase of the complex coherence coefficient can be obtained by measuring the interference fringes.

With reference to fig. 1, the whole imaging system includes a lens array, a PIC integrated chip, and an optical signal acquisition and processing unit. A multi-channel phase-shift interferometer array is integrated in the PIC chip, each group of interferometers comprises an optical waveguide and a beam combiner, and the total number of the interferometers is two input ports and four output ports. When the system is used for imaging, interference fringes are not directly generated, and the fringes are sampled at intervals of a quarter period through a beam combiner. After the sampled and output signal is detected and processed, the input light complex coherence amplitude and phase information can be obtained.

The current large-aperture telescope brings more difficulty to processing, manufacturing, assembling and debugging along with the increase of aperture, and the interference imaging system can solve the problem of insufficient resolution by configuring a long base line.

For an interference imaging system, errors have great influence on imaging quality, and the errors need to be accurately controlled in the imaging process. The PIC photonic integrated chip has a complex internal structure, integrates a beam splitter, a phase shifter, a cross waveguide and a directional coupler, and can generate errors in the manufacturing process, wherein the errors comprise phase shift errors, directional coupler errors, cross waveguide loss and the like which can influence the performance of an imaging system.

Disclosure of Invention

The invention provides an internal error calibration compensation system and a calibration compensation method of a photon interference imaging system, aiming at solving the problems that various errors exist in the device of the existing interference imaging system, and the performance of the imaging system is further influenced.

The internal error calibration compensation system of the photon interference imaging system comprises a calibration light source, a phase adjusting device, a PIC chip to be detected, a light intensity detection device and an optical fiber coupler; one end of the optical fiber coupler is connected with a calibration light source, the calibration light source is divided into two paths of output, two output ports at the other end of the optical fiber coupler are respectively connected with an input port of one phase adjusting device, and output ports of the two phase adjusting devices are respectively connected with two input ports of a PIC chip to be tested; the light intensity detection device is arranged at the rear end of the PIC chip to be detected and is used for detecting the output light intensity of four output ports of the PIC chip.

The internal error calibration compensation method of the photon interference imaging system is realized by the following steps:

step one, establishing an input/output model of a PIC chip to be tested;

in the formula, N₁And N₂In order to calibrate the input light intensity of the light source,

and

for the transmission efficiency of each transmission channel inside the PIC chip to be tested,

for the transmission efficiency of the transmission channel corresponding to the input port 1,

the transmission efficiency of the transmission channel corresponding to the input port 2;

and

for the amplitude and phase of the complex visibility of the object,

andfor the amplitude and phase of the complex visibility of the PIC ic chip,

for calibrationThe overall phase difference of the light sources is,

the output light intensity of the output port of the PIC chip to be tested;

turning on a calibration light source, adjusting an electronic delay line of the phase adjusting device to enable the phase difference of the two interference channels to be 0 and enable the phase difference to be equal to 0

Obtaining a matrix form of the input-output model of the PIC chip to be tested according to the input-output model of the PIC chip to be tested in the step one, wherein the matrix form is represented by the following formula:

in the formula (I), the compound is shown in the specification,

characteristic parameters of the PIC chip device to be tested are obtained;

thirdly, cutting off optical signals input by the input port 2 of the PIC chip to be detected, detecting output signals of four output ports of the PIC chip to be detected by adopting a light intensity detection device, and recording output light intensities of the four output ports; at this time, N₁＞0，N₂0, according to the recorded output light intensity of the output port of the PIC chip to be tested

Obtaining the transmission efficiency of the transmission channel corresponding to the input port 1

Step four, cutting off the optical signal input by the input port 1 of the PIC chip to be tested, detecting the output signals of four output ports of the PIC chip to be tested through the light intensity detection device, and recording the output of the four output portsThe light intensity; at this time, N₁＝0，N₂If more than 0, according to the recorded output light intensity of the output port of the PIC chip to be tested

Obtaining the transmission efficiency of the transmission channel corresponding to the input port 2

Step five, input optical signals of two input ports of the PIC chip to be detected are kept, output signals of four output ports of the PIC chip to be detected are detected through a light intensity detection device, and output light intensities of the four output ports are recorded; at this time, N₁＞0，N₂If more than 0, according to the recorded output light intensity of the output port of the PIC chip to be tested

And obtained in step three and step four

And

to obtain

Step six, adjusting the phase of one phase adjusting device to change the phase by pi/2, at the moment,

obtaining the following matrix form of the input and output model of the PIC chip to be tested;

in the formula (I), the compound is shown in the specification,

the device characteristic parameters of the PIC chip to be tested are obtained;

step seven, input optical signals of two input ports of the PIC chip to be detected are kept, output signals of four output ports of the PIC chip to be detected are detected through a light intensity detection device, and output light intensities of the four output ports are recorded; at this time, N₁＞0,N₂If more than 0, according to the recorded output light intensity of the output port of the PIC chip to be tested

And obtained in step three and step four

And

to obtain

Step eight, obtaining according to step three, step four, step five and step seven

To establish an error compensation matrix, which is expressed by the following equation:

in the formula (I), the compound is shown in the specification,is a target characteristic parameter;

characteristic parameters of PIC integrated chip devices;

adjusting the light intensity of the calibration light source as the target to be detected, so that the input light signals of two input ports of the PIC chip to be detected pass through the light intensity detection deviceDetecting output signals of four output ports of the PIC chip to be detected, and recording output light intensities of the four output ports; according to the recorded output light intensity of the output port of the PIC chip to be tested

And

data to obtain the light source input light intensity N₁、N₂The complex visibility model value of the objectObject multiple visibility phase

Accurate measurement of input light intensity and target complex visibility is achieved.

The invention has the beneficial effects that: the invention adopts an interference imaging system, is beneficial to improving the resolution of the system and also omits the complicated manufacturing and debugging process of the traditional telescope. By integrating the interferometer on a silicon dioxide substrate, the volume of the system is reduced, and the reliability and stability of the system are improved. And the aplanatism of each path of interference arm is easy to realize by adopting a micro-machining technology. The spatial filtering function of the integrated device can eliminate interference information introduced by atmospheric transmission and improve imaging quality.

In the invention, for the internal error of the PIC integrated chip, the internal error can be effectively corrected by establishing an error calibration compensation model, so that the system can achieve a better imaging effect. The reworking of the PIC photonic integrated chip caused by errors is avoided, a complex error compensation device is omitted, and the system operation is simplified.

Drawings

FIG. 1 is a schematic diagram of a prior art interferometric imaging system;

FIG. 2 is a block diagram of an internal error calibration compensation system of the photon interference imaging system according to the present invention;

FIG. 3 is a schematic diagram of an internal error calibration compensation method of a photon interference imaging system according to the present invention.

Detailed Description