Integrated photonic device testing device based on back coupling

Abstract

The utility model provides an integrated photonic device testing device based on back coupling, which belongs to the technical field of optoelectronic devices and comprises a light source used for generating light beams; light generated by the light source forms a required wave beam through the light beam forming system; a required wave beam penetrates through a substrate of the to-be-measured optical chip, then irradiates the on-chip coupler and is coupled to the on-chip photonic device, and light passes through the photonic device and then is coupled to the free space through the on-chip coupler; the imaging system is used for carrying out imaging processing on the wave beam on the on-chip photonic device to form an imaging signal; and the detector array is used for converting the imaging signal into an electric signal. According to the scheme, structures such as a microfluidic channel and a microwave antenna are integrated on the surface of a device through heterogeneous integration or packaging, cross-domain and multidisciplinary cross application of the optical chip is realized, meanwhile, the parallel detection capability and the coupling tolerance are greatly improved, the dependence of the optical chip on precise movement control is reduced, and the cost of detection equipment is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of optoelectronic devices, in particular to an integrated photonic device testing device based on back coupling. Background Art

[0002] There are currently two main architectures for integrated photonic chip detection: vertical surface coupling based on grating couplers and end-face coupling. The main disadvantages of the two architectures include:

[0003] 1) Coupling and optical devices are performed on the same side of the chip, which limits the application scenarios of optical devices. For example, in the fields of biomedicine and chemical analysis, the processing and analysis of liquid samples have become key links, and the photonic chip and the microfluidic system need to be packaged together to form an on-chip sensing system with integrated optical and liquid paths. In the process of co-packaging the microfluidic system and the photonic chip, sufficient space needs to be reserved on the top or side to accommodate the coupled input optical fiber. The mutual occupation of the packaging space makes the packaging process very complicated and has poor reliability, which limits the large-scale application and promotion of on-chip photoelectric sensors.

[0004] 2) The multi-channel parallel detection capability is mainly limited by the number of fiber array channels. At present, it is difficult to significantly increase the number of fiber array channels and the channel spacing error, resulting in insufficient parallel detection capability. For applications such as sensing, insufficient parallel detection capability will not be able to fully utilize the large-scale sensor integration capabilities of integrated photonic technology, limiting the number of objects that can be detected simultaneously by the photonic chip.

[0005] 3) The coupling tolerance of the grating coupler and the end face is in the micron level, and ideally requires simultaneous alignment in six dimensions, which places extremely high demands on the accuracy and movement control of the translation stage, resulting in excessively high costs for the detection equipment and being easily affected by environmental factors. Although the insertion loss of the device must be minimized as much as possible for applications such as optical communications, the requirements for coupling loss are not high for application scenarios such as fast device screening and sensing.

[0006] Based on the above limitations and needs, the present invention proposes a back-coupling solution, which realizes the spatial separation of the device and the coupling by placing the coupling device on the back of the chip, and facilitates the integration of microfluidic channels, microwave antennas and other structures on the device surface through heterogeneous integration or packaging, so as to realize the cross-domain and multidisciplinary application of optical chips. At the same time, the use of free-space optical devices for optical coupling and detection can greatly improve the parallel detection capability and coupling tolerance, reduce the dependence of optical chips on precision motion control, and reduce the cost of detection equipment. Utility Model Content

[0007] In view of this, an embodiment of the utility model provides an integrated photonic device testing device based on back coupling, which at least partially solves the problems existing in the prior art.

[0008] The present invention provides a back-coupling-based integrated photonic device testing device, comprising:

[0009] A light source, the light source is used to generate a light beam;

[0010] A beam forming system, wherein the light generated by the light source is formed into a desired beam through the beam forming system;

[0011] The optical chip to be measured, the required beam penetrates the substrate of the optical chip to be measured and then irradiates the on-chip coupler and is coupled to the on-chip photonic device. After passing through the photonic device, the light is coupled to the free space by the on-chip coupler.

[0012] An imaging system, wherein the imaging system performs imaging processing on the beam on the on-chip photonic device to form an imaging signal;

[0013] A detector array converts the imaging signal into an electrical signal.

[0014] According to a specific implementation of the utility model, the light source is one of a single tunable laser, a plurality of tunable lasers, and a fixed wavelength laser.

[0015] According to a specific implementation of the present invention, the light source is a broadband light source.

[0016] According to a specific implementation of the utility model, the light source is a fixed single-wavelength laser, and the light source is combined with an on-chip coherent demodulation device to convert phase changes into intensity signals.

[0017] According to a specific implementation of the utility model, the beam shaping system collimates or focuses the beam generated by the light source as required, so that the spot size of the beam after passing through the chip substrate matches the on-chip input coupler.

[0018] According to a specific implementation of the utility model, the receiving area of ​​the on-chip input coupler is increased by using a waveguide metamaterial structure and a coupler array method, thereby increasing the coupling tolerance.

[0019] According to a specific implementation of the utility model, light after passing through the on-chip optical device is coupled into the free space through the on-chip output coupler, and the imaging system images the on-chip output coupler onto the detector array, and the number of channels collected is determined by the number of array elements in the detector array and the zoom factor of the imaging system.

[0020] The scheme of the utility model includes: a light source, a beam shaping module, a light chip to be measured, an imaging system and a detector array. The light generated by the light source is formed into a required beam by the beam shaping module, penetrates the chip substrate and irradiates the on-chip coupler and is coupled to the on-chip photonic device. After passing through the photonic device, the light is coupled to the free space by the on-chip coupler, and is imaged to the detector array by the imaging system and converted into an electrical signal.

[0021] The beneficial effects of the coupling scheme of the utility model include:

[0022] 1) Separation of coupling and back-end packaging structure: The spatial isolation of the coupling optical path and the back-end packaging structure such as microfluidics is achieved through back coupling, thereby reducing the complexity of packaging, reducing costs, and improving the integration and reliability of the system;

[0023] 2) Parallel detection: multi-channel parallel data acquisition is achieved through imaging systems and detector arrays;

[0024] 3) High tolerance: By replacing the common single-mode optical fiber as the input end with a free-space optical system and using an imaging system as the output end, the accuracy of coupling alignment is reduced, the cost is reduced, and the device tolerance is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of a back-coupling solution provided in an embodiment of the utility model;

[0027] Figure 2 A typical structural schematic diagram of an integrated photonic device testing device based on back coupling is provided for an embodiment of the utility model. DETAILED DESCRIPTION

[0028] The embodiments of the utility model are described in detail below with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the back-coupling scheme proposed in the present invention mainly consists of the following parts: light source, beam shaping module, optical chip to be measured, imaging system and detector array. The light generated by the light source is formed into the required beam by the beam shaping module, penetrates the chip substrate and irradiates the on-chip coupler and is coupled to the on-chip photonic device. After passing through the photonic device, the light is coupled to the free space by the on-chip coupler, imaged to the detector array by the imaging system, and converted into an electrical signal.

[0030] The light source can be a single or multiple tunable lasers or fixed wavelength lasers, or a broadband light source, depending on the type of optical device and signal demodulation scheme. Taking the interferometric on-chip sensor as an example, if a phase demodulation scheme is adopted, a fixed single wavelength laser can be selected as the light source, combined with an on-chip coherent demodulation device, to convert the phase change into an intensity signal, which is received by the detector and converted into an electrical signal.

[0031] The beam shaping system can collimate or focus the light beam generated by the light source as needed, so that the spot size of the light beam after passing through the chip substrate matches the on-chip input coupler. The typical pattern spot diameter of a single on-chip input coupler is 8 to 10 microns. The spot size of the light beam after passing through the chip substrate can be appropriately larger than this size to balance the coupling tolerance and coupling efficiency. The receiving area of ​​the on-chip input coupler can also be increased through waveguide metamaterial structures, coupler arrays and other solutions, thereby increasing the coupling tolerance.

[0032] The light after passing through the on-chip optical device is coupled into free space through the on-chip output coupler, and the imaging system images the on-chip output coupler onto the detector array. The number of channels that can be collected simultaneously by this solution is determined by the number of detector array elements and the scaling factor of the imaging system. It can realize multi-channel data collection simultaneously and is easy to expand. Since fiber alignment is not required, the tolerance is greatly improved.

[0033] Taking the on-chip interferometer sensor as an example, the typical connection relationship between the various parts is as follows Figure 2 As shown, the light source outputs single-wavelength light through the focusing lens fiber, and is input into the grating coupler from the back of the chip. By selecting the lens parameters, the spot radius can be changed. For example, if the spot diameter reaches about 30 microns, an alignment tolerance of 15 microns can be obtained. The light is coupled to the waveguide structure of the sensing area, and then the light signal is output from the back of the chip through the grating coupler, and is imaged onto the detector array surface through the imaging system, which can realize multi-channel parallel detection.

[0034] The beneficial effects of this coupling scheme include:

[0035] 1) Separation of coupling and back-end packaging structure: The spatial isolation of the coupling optical path and the back-end packaging structure such as microfluidics is achieved through back coupling, thereby reducing the complexity of packaging, reducing costs, and improving the integration and reliability of the system;

[0036] 2) Parallel detection: multi-channel parallel data acquisition is achieved through imaging systems and detector arrays;

[0037] 3) High tolerance: By replacing the common single-mode optical fiber as the input end with a free-space optical system and using an imaging system as the output end, the accuracy of coupling alignment is reduced, the cost is reduced, and the device tolerance is improved.

[0038] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A back-coupling-based integrated photonic device testing device, characterized in that: include: A light source, the light source is used to generate a light beam; A beam forming system, wherein the light generated by the light source is formed into a desired beam through the beam forming system; The optical chip to be measured, the required beam penetrates the substrate of the optical chip to be measured and then irradiates the on-chip coupler and is coupled to the on-chip photonic device. After passing through the photonic device, the light is coupled to the free space by the on-chip coupler. An imaging system, wherein the imaging system performs imaging processing on the beam on the on-chip photonic device to form an imaging signal; A detector array converts the imaging signal into an electrical signal.

2. The device according to claim 1, characterized in that: The light source is one of a single tunable laser, a plurality of tunable lasers or a fixed wavelength laser.

3. The device according to claim 2, characterized in that: The light source is a broadband light source.

4. The device according to claim 3, characterized in that: The light source is a fixed single-wavelength laser, and the light source is combined with an on-chip coherent demodulation device to convert phase changes into intensity signals.

5. The device according to claim 4, characterized in that: The beam shaping system collimates or focuses the light beam generated by the light source as needed, so that the spot size of the light beam after passing through the chip substrate matches the on-chip input coupler.

6. The device according to claim 5, characterized in that: The receiving area of ​​the on-chip input coupler is increased by using waveguide metamaterial structure and coupler array method, thereby improving the coupling tolerance.

7. The device according to claim 6, characterized in that: The light after passing through the on-chip optical device is coupled into the free space through the on-chip output coupler. The imaging system images the on-chip output coupler onto the detector array. The number of channels collected is determined by the number of detector array elements and the scaling factor of the imaging system.

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