CN119803689A - An on-chip light field wavefront measurement system and method based on grating coupler - Google Patents
An on-chip light field wavefront measurement system and method based on grating coupler Download PDFInfo
- Publication number
- CN119803689A CN119803689A CN202411984678.8A CN202411984678A CN119803689A CN 119803689 A CN119803689 A CN 119803689A CN 202411984678 A CN202411984678 A CN 202411984678A CN 119803689 A CN119803689 A CN 119803689A
- Authority
- CN
- China
- Prior art keywords
- wavefront
- array
- waveguide
- grating coupler
- measured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Testing Of Optical Devices Or Fibers (AREA)
Abstract
本发明属于光场波前测量相关技术领域，其公开了一种基于光栅耦合器的片上光场波前测量系统及方法。该系统包括依次连接的光栅耦合器阵列、光纤阵列、光纤及光电探测器；光栅耦合器阵列设置在硅光子芯片上并用于将待测波前耦合至波导内，并将波前角度转换为波导内光强信号；光纤阵列，用于将耦合至波导内的光强信号传输至光电探测器；光电探测器，用于接收光强信号，并对光强信号进行光电转换处理，得到待测波前的特征参数。本发明通过光栅耦合器阵列将波前角度转换为波导内的光强信号，并根据光电探测器所接收到的光强信号对待测波前进行重构，该测量方法装置简单，空间分辨率高且动态角度范围大。
The present invention belongs to the technical field related to light field wavefront measurement, and discloses an on-chip light field wavefront measurement system and method based on a grating coupler. The system includes a grating coupler array, an optical fiber array, an optical fiber and a photodetector connected in sequence; the grating coupler array is arranged on a silicon photonic chip and is used to couple the wavefront to be measured into a waveguide, and convert the wavefront angle into a light intensity signal in the waveguide; the optical fiber array is used to transmit the light intensity signal coupled into the waveguide to the photodetector; the photodetector is used to receive the light intensity signal, and perform photoelectric conversion processing on the light intensity signal to obtain the characteristic parameters of the wavefront to be measured. The present invention converts the wavefront angle into a light intensity signal in the waveguide through a grating coupler array, and reconstructs the wavefront to be measured according to the light intensity signal received by the photodetector. The measurement method has a simple device, high spatial resolution and a large dynamic angle range.
Description
Technical Field
The invention belongs to the technical field of optical information measurement, and particularly relates to an on-chip optical field wavefront measurement system and method based on a grating coupler.
Background
The wavefront sensing has wide application in astronomical self-adaptive optics, micro-nano three-dimensional morphology measurement, laser communication, biological quantitative phase microscopic imaging and other fields. The traditional wave-front phase sensing method mainly comprises a shack-Hartmann wave-front sensor, digital holographic quantitative phase imaging and the like.
Conventional phase measurement techniques typically employ complex optics that are difficult to meet a number of practical application requirements. The traditional shack-Hartmann sensor based on the micro lens array has the advantages of simpler device, lower imaging resolution and smaller dynamic range, and can only meet the wavefront measurement requirement with low partial resolution requirement.
In recent years, silicon photonic chips have been widely used in the fields of optical communication, optical computing, optical sensing, and the like. The micro-nano optical device on the chip enables the miniaturization and microminiaturization of the traditional optical measurement equipment due to the flexible regulation and control of the optical polarization, the phase and the amplitude.
Disclosure of Invention
Aiming at the defects and improvement demands of the prior art, the invention provides an on-chip light field wavefront measurement system and method based on a grating coupler, which utilize the grating coupler to convert the angle information of the wavefront to be measured into the light intensity information in a waveguide, and measure the light intensity signals in the waveguide through an optical fiber array and a photoelectric detector to determine the angle information of the wavefront to be measured at each space position, so as to realize a wavefront measurement system with high resolution and high dynamic range.
In order to achieve the above object, according to a first aspect of the present invention, there is provided an on-chip optical field wavefront measurement system based on a grating coupler, including a grating coupler array, an optical fiber, and a photodetector connected in sequence;
The grating coupler array is arranged on the silicon photon chip and comprises a grating coupling unit array and a waveguide array which are positioned in the same plane, wherein the grating coupling unit array is used for receiving a wavefront to be detected, coupling the wavefront to be detected into the waveguide array and converting a wavefront angle signal into a light intensity signal in the waveguide array;
The optical fiber array is used for coupling the light intensity signals in the waveguide array into the optical fibers and transmitting the light intensity signals to the photoelectric detector through the optical fibers;
the photoelectric detector is used for carrying out photoelectric conversion processing on the light intensity signals to obtain characteristic parameters of the wavefront to be detected.
Further, the grating coupler unit array includes four grating couplers forming an included angle of 90 degrees with each other in the same plane, a waveguide is disposed at one end of each grating coupler far away from each other, each grating coupler couples the wavefront to be measured into the waveguide, and the waveguides are used for forming the waveguide array.
Further, the optical fiber array couples the light intensity signals in the waveguide into the optical fibers through an edge coupler or a vertical coupler.
Further, the photoelectric detector is a CMOS camera, a CCD camera or a multichannel optical power meter.
According to another aspect of the present invention, the present invention further provides a method for measuring a wavefront characteristic parameter to be measured by using the above measurement system, including:
S1, determining light intensity signals in the waveguide array according to the light intensity signals in the optical fiber array received by the photoelectric detector:
s2, calculating the normalized coupling power ratio of the grating coupler array in the plane according to the light intensity signals in the waveguide array;
S3, calculating a wavefront angle corresponding to the wavefront to be measured under the current normalized coupling power ratio according to a response curve of the normalized coupling power ratio calibrated in advance and the wavefront angle to be measured;
And S4, integrating the wave-front angle measured values at different positions by utilizing a regional wave-front reconstruction algorithm according to the wave-front angle to determine the wave-front distribution to be measured.
Further, in the step S2-S3, the plane is a plane formed by xy directions, the grating coupler array includes grating couplers distributed in the four directions of +x, -x, +y and y in the plane, the direction of the wavefront to be measured is a z direction perpendicular to the plane, and the normalized coupling power ratio of the grating couplers in the +x and-x directions is:
the normalized coupling power ratio of the grating coupler in the +y direction and the-y direction is as follows:
Wherein the normalized coupled power ratios in the x-direction and the y-direction, R x and R y, respectively, are monotonic functions with respect to the wavefront angle θ x and the wavefront angle θ y;
The power P +x in the waveguide is Gaussian distribution about a wave-front angle theta x, the coupling peak angle is theta 1, the wave-front angle theta x is an included angle between the wave-front to be measured projected into an xz plane and the x direction, P -x is a response curve about the wave-front angle theta x and symmetrical with P +x about a yz plane, P +y is Gaussian distribution about the wave-front angle theta y, wherein theta y is an included angle between the wave-front to be measured projected into the yz plane and the y direction, P -y is a response curve about the wave-front angle theta y and symmetrical with P +y about the xz plane.
Further, the grating coupler structure distributed along the +x direction is obtained by constructing an objective function of the grating coupler structure, so that when the wave front angle to be measured is theta 1, the power of the transmission waveguide along the +x direction is maximum, and solving and calculating by using an intelligent optimization algorithm to obtain the optimal grating coupling unit structure.
In general, through the above technical solutions conceived by the present invention, the following beneficial effects can be obtained:
1. the invention provides an on-chip light field wavefront measuring system and a novel method based on a grating coupler, which utilize the grating coupler to convert the angle information of the wavefront to be measured into light intensity information in a waveguide, and can uniquely determine the angle information of the wavefront to be measured at each spatial position by measuring the light intensity signals in the waveguide through an optical fiber array and a photoelectric detector.
2. The on-chip light field wavefront measurement system provided by the invention only depends on the size of the grating coupler, and can realize higher spatial resolution compared with the traditional wavefront sensor based on the micro lens array.
3. The optimal measurement method can uniquely determine the angle information of the wavefront to be measured by calculating the normalized coupling power ratios of four different directions in the same plane, has simple data processing process and small calculation amount, and further improves the measurement efficiency.
Drawings
FIG. 1 is a schematic diagram of an on-chip optical field wavefront measurement system based on a grating coupler according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a grating coupler array provided in an embodiment of the present invention;
FIG. 3 is a graph showing the variation of +x-direction and-x-direction waveguide coupling power with the measured wavefront angle θ x provided in an embodiment of the present invention;
Fig. 4 is a graph showing the variation of the x-direction normalized power ratio R x with the wavefront angle θ x to be measured, provided in an embodiment of the present invention.
The same reference numbers are used throughout the drawings to reference like elements or structures, wherein:
A grating coupler array 100, a grating coupler 101, a waveguide array 102, an optical fiber array 200, and a photodetector 300.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
The first aspect of the present invention proposes an on-chip optical field measurement system based on a grating coupler, as shown in fig. 1, the system comprises a grating coupler array 100, an optical fiber array 200, an optical fiber and a photodetector 300 connected in sequence, wherein the direction of light propagation is the z-axis, and the grating coupler array 100 is located in the xy-plane, wherein:
The grating coupler array 100 is disposed on a silicon photonic chip, and comprises a grating coupling unit array 101 and a waveguide array 102, which are located in the same plane, wherein the grating coupling unit array 101 is used for receiving a wavefront to be measured, coupling the wavefront to be measured into the waveguide array 102, and converting a wavefront angle signal into a light intensity signal in the waveguide array 102.
The fiber array 200 is used to couple the light intensity signals within the waveguide array 102 into the optical fibers and to transmit to the photodetector 300.
The photodetector 300 is configured to receive the light intensity signal in the optical fiber array 200, and perform photoelectric conversion processing on the light intensity signal to obtain a characteristic parameter of the wavefront to be measured.
Further, as shown in fig. 2, the grating coupling unit 101 includes grating couplers distributed in the four directions of +x, -x, +y and y in the plane, one waveguide is disposed at one end of each grating coupler away from each other, each grating coupler couples the wavefront to be measured into the waveguide, the waveguides are used to form the waveguide array 102, and each grating coupler converts the angle of the wavefront to be measured into the power P +x,P-x,P+y,P-y in four independent waveguides at the same time. The grating couplers in the +x direction and the-x direction are used for measuring an included angle theta x between the projection of the wavefront to be measured and the x axis in the xz plane, and the grating couplers in the +y direction and the-y direction are used for measuring an included angle theta y.θx between the projection of the wavefront to be measured and the y axis in the yz plane, and the measuring structures and the measuring principles of theta y are the same, and the measuring principles of theta x are now described. The power P +x of the +x-direction grating coupler coupling the wavefront to be measured into the waveguide is a gaussian curve about the angle θ x of the wavefront to be measured, with a coupling peak angle of θ 1, as shown in fig. 3. The response curve of P -x and P +x are symmetrical about the yz plane. The normalized coupling power ratio of the grating coupler in +x and-x directions is:
As shown in fig. 4, the normalized coupled power ratio R x in the x-direction is a monotonic function with respect to θ x. The measuring principle of the angle theta x.θy of the wavefront to be measured can be uniquely determined by measuring R x is the same as that of the angle theta x, and the angle theta y of the wavefront to be measured can be uniquely determined by measuring R y.
Furthermore, the design of the grating coupler is optimized according to the performance requirement of wavefront detection and the wavelength of the wavefront to be detected. Since the grating couplers arranged in four directions are identical in size, only a single grating coupler needs to be optimally designed. Taking a grating coupler along the +x direction as an example, an objective function of the grating coupler structure is constructed so that the power of the transmission waveguide along the +x direction is maximum when the wave front angle to be measured is theta 1. And solving and calculating by using a common intelligent optimization algorithm, such as a particle swarm optimization and simulated annealing algorithm, so as to obtain the optimal grating coupling unit structure.
Further, the fiber array 200 may couple the light intensity signals within the waveguide into the array fibers through an edge coupler or a vertical coupler.
Further, the photodetector 300 may employ a CMOS camera, a CCD camera, or a multichannel optical power meter.
In specific implementation, the on-chip optical field wavefront measurement method provided by the invention comprises the following steps:
1. The light intensity signal in the waveguide 102 is determined by the light intensity signal received by the photodetector 300 in the optical fiber array 200, P +x,P-x,P+y,P-y;
2. Calculating normalized coupling power ratios R x and R y in the x-direction and the y-direction from the light intensity signals within the waveguide array 102;
3. According to a response curve of a pre-calibrated normalized coupling power ratio and a wavefront angle to be measured, calculating the wavefront angles theta x and theta y of corresponding wavefront to be measured under the current R x and R y;
4. and according to the wave front angles theta x and theta y to be measured, the wave front distribution condition to be measured can be determined by integrating wave front angle measurement values at different positions by utilizing a regional wave front reconstruction algorithm.
It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (7)
1. An on-chip optical field wavefront measurement system based on a grating coupler is characterized by comprising a grating coupler array, an optical fiber and a photoelectric detector which are connected in sequence;
The grating coupler array is arranged on the silicon photon chip and comprises a grating coupling unit array and a waveguide array which are positioned in the same plane, wherein the grating coupling unit array is used for receiving a wavefront to be detected, coupling the wavefront to be detected into the waveguide array and converting a wavefront angle signal into a light intensity signal in the waveguide array;
The optical fiber array is used for coupling the light intensity signals in the waveguide array into the optical fibers and transmitting the light intensity signals to the photoelectric detector through the optical fibers;
the photoelectric detector is used for carrying out photoelectric conversion processing on the light intensity signals to obtain characteristic parameters of the wavefront to be detected.
2. The system of claim 1, wherein the array of grating coupler units comprises four grating couplers disposed at 90 ° angles to each other in a same plane, each of the grating couplers being provided with a waveguide at an end thereof remote from each other, each of the grating couplers respectively coupling a wavefront to be measured into the waveguide, the waveguides being configured to form the array of waveguides.
3. An on-chip optical field wavefront measurement system based on a grating coupler according to claim 1 or 2, wherein the optical fiber array couples the optical intensity signal in the waveguide into the optical fiber through an edge coupler or a vertical coupler.
4. An on-chip optical field wavefront measuring system based on a grating coupler according to claim 1 or 2, wherein the photodetector is a CMOS camera, a CCD camera or a multichannel optical power meter.
5. A measurement method for measuring a wavefront characteristic to be measured using the measurement system according to any one of claims 1 to 4, comprising:
S1, determining light intensity signals in the waveguide array according to the light intensity signals in the optical fiber array received by the photoelectric detector:
s2, calculating the normalized coupling power ratio of the grating coupler array in the plane according to the light intensity signals in the waveguide array;
S3, calculating a wavefront angle corresponding to the wavefront to be measured under the current normalized coupling power ratio according to a response curve of the normalized coupling power ratio calibrated in advance and the wavefront angle to be measured;
And S4, integrating the wave-front angle measured values at different positions by utilizing a regional wave-front reconstruction algorithm according to the wave-front angle to determine the wave-front distribution to be measured.
6. The method according to claim 5, wherein in the step S2-S3, the plane is a plane formed by xy directions, the grating coupler array includes grating couplers distributed in four directions of +x, -x, +y and y in the plane, the direction of the wavefront to be measured is a z direction perpendicular to the plane, and the normalized coupling power ratio of the grating couplers in the +x and-x directions is:
the normalized coupling power ratio of the grating coupler in the +y direction and the-y direction is as follows:
Wherein the normalized coupled power ratios in the x-direction and the y-direction, R x and R y, respectively, are monotonic functions with respect to the wavefront angle θ x and the wavefront angle θ y;
The power P +x in the waveguide is Gaussian distribution about a wave-front angle theta x, the coupling peak angle is theta 1, the wave-front angle theta x is an included angle between the wave-front to be measured projected into an xz plane and the x direction, P -x is a response curve about the wave-front angle theta x and symmetrical with P +x about a yz plane, P +y is Gaussian distribution about the wave-front angle theta y, wherein theta y is an included angle between the wave-front to be measured projected into the yz plane and the y direction, P -y is a response curve about the wave-front angle theta y and symmetrical with P +y about the xz plane.
7. The method according to claim 6, wherein the grating coupler structure distributed along the +x direction is obtained by constructing an objective function of the grating coupler structure so that the power of the transmission waveguide along the +x direction is maximum when the angle of the wavefront to be measured is theta 1, and solving and calculating by using an intelligent optimization algorithm to obtain the optimal grating coupling unit structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411984678.8A CN119803689B (en) | 2024-12-31 | 2024-12-31 | On-chip light field wavefront measurement system and method based on grating coupler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411984678.8A CN119803689B (en) | 2024-12-31 | 2024-12-31 | On-chip light field wavefront measurement system and method based on grating coupler |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN119803689A true CN119803689A (en) | 2025-04-11 |
| CN119803689B CN119803689B (en) | 2025-10-14 |
Family
ID=95259567
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411984678.8A Active CN119803689B (en) | 2024-12-31 | 2024-12-31 | On-chip light field wavefront measurement system and method based on grating coupler |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119803689B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020001088A1 (en) * | 2000-02-23 | 2002-01-03 | Ulrich Wegmann | Apparatus for wavefront detection |
| CN104198053A (en) * | 2014-08-19 | 2014-12-10 | 北京理工大学 | Wavefront detection method based on sub-wavelength grating array wavefront sensor |
| CN107884876A (en) * | 2017-12-23 | 2018-04-06 | 长安大学 | A kind of polarization state detection chip based on Waveguide grating coupler |
| CN108169175A (en) * | 2016-12-08 | 2018-06-15 | 松下知识产权经营株式会社 | Optical detection system and light-emitting device |
-
2024
- 2024-12-31 CN CN202411984678.8A patent/CN119803689B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020001088A1 (en) * | 2000-02-23 | 2002-01-03 | Ulrich Wegmann | Apparatus for wavefront detection |
| CN104198053A (en) * | 2014-08-19 | 2014-12-10 | 北京理工大学 | Wavefront detection method based on sub-wavelength grating array wavefront sensor |
| CN108169175A (en) * | 2016-12-08 | 2018-06-15 | 松下知识产权经营株式会社 | Optical detection system and light-emitting device |
| CN107884876A (en) * | 2017-12-23 | 2018-04-06 | 长安大学 | A kind of polarization state detection chip based on Waveguide grating coupler |
Also Published As
| Publication number | Publication date |
|---|---|
| CN119803689B (en) | 2025-10-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110687518B (en) | An on-chip integrated balanced detection receiving system and method | |
| CN110954966B (en) | Planar Photoelectric Detection System Based on Metalens Array | |
| US10215970B2 (en) | Image-pickup optical system and image pickup apparatus to correct aberration | |
| US12265181B2 (en) | Scanner, and coaxial, and non-coaxial lidar systems with same | |
| CN113835155A (en) | Free space light and photon chip grating coupling method | |
| CN201589623U (en) | Demodulation device for fiber grating sensors | |
| CN112665532A (en) | High-precision laser warning device based on four-quadrant detector and two-dimensional grating | |
| CN107748397A (en) | A kind of method of sampling of compact rectangular aperture arrangement and object space frequency | |
| CN203216701U (en) | Aberration detection device for image transmitting optical fiber bundles | |
| CN119803689B (en) | On-chip light field wavefront measurement system and method based on grating coupler | |
| CN101414033B (en) | Optical fiber linear array digital element, device and imaging method | |
| CN119437445B (en) | A wavefront measurement module and method for optical fields based on integrated photonic chips | |
| CN101876712A (en) | Time-space resolution measurement system of pulsed radiation field based on fiber optic bundle | |
| CN115151010B (en) | A system for measuring ion temperature and its disturbance in a magnetic confinement device | |
| CN114236681B (en) | On-chip one-dimensional converging lens device and preparation method thereof | |
| CN111045219A (en) | Planar photodetection system based on dichroic focusing diffractive optical element | |
| CN206670570U (en) | A kind of optical fiber distance measurement system | |
| US20230160684A1 (en) | Simultaneous phase-shift point diffraction interferometer and method for detecting wave aberration | |
| CN201302613Y (en) | Optical fiber linear array digital elements and devices | |
| CN118869075B (en) | A space laser communication device and control method thereof | |
| CN119758292B (en) | Micro-integrated coherent balance detector and detection method | |
| CN105865626A (en) | Hyperspectral imager based on rotary filter monochromator | |
| CN222866056U (en) | Measuring system for spin and orbital angular momentum of high-order Poincare ball beam | |
| CN117629405B (en) | Spectrometer | |
| CN120869355B (en) | A pixel-level all-Stokes polarization imaging system and its image reconstruction method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |