Optical sensor chip and optical sensing system

Abstract

The present invention provides an optical sensor chip and an optical sensing system, the optical sensor chip of the present invention includes a bottom clad layer, a top clad layer stacked on the bottom clad layer, and an optical waveguide core, the optical waveguide core is disposed between the top clad layer and the bottom clad layer, the top clad layer is provided with a hollow portion for accommodating a sample to be measured, and a part of the optical waveguide core is exposed by the hollow portion, the optical waveguide core includes a first polarization rotator and a first polarization separator, the first polarization separator includes an input port and two output ports for outputting polarized light, the first polarization rotator is provided with a first end and a second end, the second end of the first polarization rotator is connected to the input port of the first polarization separator, and the dimension of the first polarization rotator gradually increases along a direction from the first end to the second end. The optical sensor chip of the present invention can be designed in different sizes as required, does not require a large volume, is easy to use, does not require a tunable laser, and is low in cost.

Description

[Technical field]

[0001] <CROSS REFERENCE TO RELATED APPLICATIONS> This application claims priority to a Chinese patent application having application number 2021112554022, filed on October 27, 2021. The contents of the above application are incorporated herein by reference.

[0002] The present invention relates to the technical field of optical sensors, and in particular to optical sensor chips and optical sensing systems. [Background technology]

[0003] Optical sensors and instruments are based on optical principles for measurement, and optical sensors mainly include optical image sensors, optical measurement sensors, optical mouse sensors, reflective optical sensors, optical biosensors, etc.

[0004] Optical biosensing technologies mainly include Surface Plasmon Resonance (SPR) technology and integrated silicon photonics technology. The SPR method uses a system including a laser, a prism connected to a gold surface, and a detector. In SPR, a test protein is immobilized on a gold surface, an unlabeled query protein is added, and the change in the light reflection angle due to the binding between the probe and the immobilized protein is measured to characterize the presence of the analyte in real time. SPR systems are relatively large and are often used in laboratory experiments or large equipment. In integrated silicon photonics biosensors, detection is usually achieved by combining the biosensor with a liquid containing the analyte (e.g., an antibody and a virus), and the analyte and the biosensor interact with each other to cause a change in the refractive index.

[0005] The system structures of existing silicon photonics biosensors can be divided into several types based on their physical transmission principles. The first type is based on an interferometer structure, such as a Mach-Zehnder interferometer. The second type is based on a resonator structure including an annular resonator, a microcavity, a photonic crystal, a Bragg grating, etc. For silicon photonics biosensors with these two structures, the refractive index change is detected by wavelength shift measurement. Specifically, the spectrum measurement is repeated by scanning a tunable laser, and curve fitting is performed on these spectra to extract peak values ​​and track the time change of the peak values. This allows information about the binding between the analyte and the waveguide surface to be obtained.

[0006] For example, a sensing system consists of a silicon photonics chip with a ring resonator and an external tunable laser to detect the interaction of biomolecules with the ring resonator by measuring the spectrum. The need for a tunable laser increases the cost of silicon photonics biosensing solutions and also increases the volume of the system. The sensitivity of these sensors can be defined as the spectral displacement divided by the top cladding index change. The detection limit can be defined as the smallest refractive index change we can measure, which requires the tunable laser to have high tuning resolution and precision. The higher the tuning resolution, the more expensive the tunable laser becomes, making it inconvenient for commercialization and large-scale deployment. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE PRESENT EMBODIMENT The objective of the present invention is to provide an optical sensor chip and an optical sensing system to avoid the dependency on tunable lasers and improve the problems of the huge volume, ease of use and high cost of the sensing system. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides an optical sensor chip including a bottom clad layer, a top clad layer stacked on the bottom clad layer, and an optical waveguide core, the optical waveguide core being disposed between the top clad layer and the bottom clad layer, the top clad layer being provided with a hollow portion for accommodating a sample to be measured, a part of the optical waveguide core being exposed by the hollow portion, the optical waveguide core including a first polarization rotator and a first polarization separator, the first polarization separator including an input port and two output ports including a through port and a coupling port, both of which are for outputting polarized light, the first polarization rotator being disposed on the same line as the first polarization separator, the first polarization rotator being provided with a first end and a second end, the second end of the first polarization rotator being connected to the input port of the first polarization separator, and the size of the first polarization rotator gradually increasing along a direction from the first end to the second end.

[0009] The beneficial effect of the optical sensor chip of the present invention is that the optical waveguide core is disposed between the top clad layer and the bottom clad layer, and a hollow portion is disposed in the top clad layer, so that a sample to be measured is placed on the optical sensor chip, and the sample to be measured and the optical waveguide core can be in contact with each other and interact with each other; light is inputted into the first end of the optical waveguide core, and the movement of photons is guided by the optical waveguide core, and the dimension of the optical waveguide core gradually increases from the first end to the second end; the photons in the first polarization rotator of the optical waveguide core generate polarization rotation due to the refractive index difference between the sample to be measured and the clad layer, and are coupled to the input port of the first polarization separator by the second end of the first polarization rotator. In this way, the photons after polarization rotation are input into the first polarization separator, and the photons are output by the two output ports of the first polarization separator, the two output ports including a through port and a coupling port, the polarization includes transverse magnetic field TM polarization and transverse magnetic field TE polarization, most of the transverse magnetic field TM polarization is output by the through port, a small portion of the transverse magnetic field TE polarization is output by the through port, most of the transverse magnetic field TE polarization is output by the coupling port, and a small portion of the transverse magnetic field TM polarization is output by the coupling port, and based on the difference in the strength of the transverse magnetic field TE polarization and the transverse magnetic field TM polarization output by the through port and the coupling port, the characteristics of the sample to be measured can be further detected, and the results can be easily analyzed. Therefore, the operating principle of the optical sensor chip of the present invention is based on the rotation and separation of optical polarization, and unlike the existing photon sensors based on interferometer structure and resonator structure, there is no need to use a tunable laser, and the cost is low. The optical sensor chip of the present application can be designed in different sizes as needed, does not need to set a large volume, and can be designed into a chip with very small dimensions, making it easy to use.

[0010] In one possible embodiment, the optical waveguide core further includes a second polarization rotator and a second polarization separator, the second polarization separator and the second polarization rotator are both arranged in the same line as the first polarization rotator, the second polarization rotator is disposed between the second polarization separator and the first polarization rotator, the second polarization separator includes two input ports including a through input port and a coupling input port, and one output port, the output port of the second polarization separator is connected to the input port of the second polarization rotator, the output port of the second polarization rotator is connected to the input port of the first polarization rotator, the coupling input port of the second polarization separator is used to transmit the input transverse electric field TE polarized light to the second polarization rotator, the second polarization rotator is used to convert the transverse electric field TE polarized light to transverse magnetic field TM polarized light, and the output port of the second polarization separator is used to input the transverse magnetic field TM polarized light to the first polarization rotator. The beneficial effect is that the input port of the first polarization rotator can only receive the input of transverse magnetic TM polarized light, but the commonly used existing light source usually outputs transverse electric TE polarized light, so by providing the second polarization separator and providing two input ports and one output port, the output port of the second polarization separator communicates with the input port of the first polarization rotator, so that the transverse electric TE polarized light can be input through the combined input port of the second polarization separator, and the input transverse electric TE polarized light can be converted into transverse magnetic TM polarized light by the second polarization separator, and then input into the first polarization rotator, which is easy to use in practice. In one possible embodiment, the structural shape of the first polarization rotator is a tapered shape or a wedge shape. The beneficial effect is that by providing it in this way, the photons can cause polarization rotation in the first polarization rotator due to the refraction difference between the sample to be measured and the cladding layer.

[0011] In one possible embodiment, the optical waveguide core is spatially arranged in a spiral or folded manner, the beneficial effect of which is that it makes the structure more compact and enhances the local interaction between the light wave and the analyte.

[0012] In one possible embodiment, the first polarization separator includes one of the following: a directional coupler, an adiabatic coupler, a bend coupler, a Y-shaped separator, a multimode interferometer, a photonic crystal, a grating and a prism, and the second polarization separator includes one of the following: a directional coupler, an adiabatic coupler, a bend coupler, a Y-shaped separator, a multimode interferometer, a photonic crystal, a grating and a prism. The beneficial effect is that the first polarization separator and the second polarization separator can be installed as one of the following: a directional coupler, an adiabatic coupler, a bend coupler, a Y-shaped separator, a multimode interferometer, a photonic crystal, a grating and a prism, making them flexible and easy to use.

[0013] In one possible embodiment, the optical waveguide core is made of at least one of silicon, silicon nitride, silica, alumina, lithium niobate and III-V materials, the beneficial effect being that in this way, the bottom clad layer and the top clad layer can be made of multiple materials, reducing the manufacturing difficulty.

[0014] In one possible embodiment, the optical waveguide core is made of sub-wavelength structures, the beneficial effect of which is that such a configuration further improves local sensing and increases the interaction between light and analytes.

[0015] In one possible embodiment, the optical waveguide core is provided in a plurality of locations, each of the optical waveguide cores being located between the top clad layer and the bottom clad layer, with the beneficial effect being that by providing a plurality of the optical waveguide cores, different detections can be performed simultaneously by the plurality of optical waveguide cores.

[0016] In one possible embodiment, the optical sensor chip is applied to at least one of biological sensing, gas sensing, temperature sensing, humidity sensing, odor sensing, chemical sensing, water quality monitoring and greenhouse monitoring. The beneficial effect is that based on different samples to be measured produce different characteristics, and when combined with the provision of a cladding layer, a variety of different refractive indices are generated, and different detection results can be obtained, so that the optical sensor chip of the present application can detect biological, gas, temperature, humidity, chemical, odor, water quality, greenhouse, etc.

[0017] The present invention further provides an optical sensing system, including a light source, a first photodetector, a second photodetector, a power source, a controller, a display, a flow controller, and the optical sensor chip according to any one of the above possible embodiments, wherein the light source is used to input light to one end of the optical sensor chip, the first photodetector and the second photodetector are disposed at the other end of the optical sensor chip, the first photodetector and the second photodetector are used to detect photoelectric signals output by two output ports of the optical sensor chip, the display is electrically connected to the first photodetector and the second photodetector respectively, the first photodetector and the second photodetector convey the photoelectric signals to the display, and the display receives and displays the photoelectric signals. the flow controller is provided with an output interface and an input interface, both of which are connected to the hollow portion of the optical waveguide core; the flow controller is used to transport the biological sample to be measured, the flow controller is used to transport the biological sample to be measured to the hollow portion via the output interface and to collect the biological sample to be measured in the hollow portion via the output interface; the controller is electrically connected to the light source, the first photodetector, the second photodetector and the flow controller, respectively; and the controller is used to control the opening and closing of the light source, the first photodetector, the second photodetector and the flow controller, respectively.

[0018] The beneficial effects of the optical sensing system of the present invention are that light rays or photons are input into the optical sensor chip by the light source, the TE polarized light and TM polarized light output by the biosensor are detected by the first photodetector and the second photodetector, and observed by the display 9; a flow controller is installed and connected to the hollow space by an input interface and an output interface, different biological samples to be measured are added into the flow controller, and detection can be performed continuously under the control of the controller, which is highly efficient, has an intuitive detection structure, and is easy to use.

[0019] In one possible embodiment, at least one of the light source, the first photodetector or the second photodetector is integrated and set on the optical sensor chip, the beneficial effect of which is that by integrating at least one of the light source, the first photodetector or the second photodetector on the optical sensor chip, the volume of the whole sensing system can be reduced, the packaging cost can be reduced, and the impact on the structure caused by the mounting error of the light source, the first photodetector or the second photodetector can be reduced.

[0020] In one possible embodiment, the light source is a fixed wavelength light source or a broadband light source, and the light source is one of a distributed feedback laser, a vertical cavity surface emitting laser, a superluminescent diode and a light emitting diode. The wavelength range of the light source includes one of visible light, O-band light, C-band light and mid-infrared light. The beneficial effect is that such an arrangement can facilitate flexible selection of light sources in practical use.

[0021] In one possible embodiment, the first photodetector, the second photodetector and the optical sensor chip are all installed in N numbers (N is a positive integer), and the optical sensing system further includes an optical splitter, which is installed between the light source and the optical sensor chip, and is used to split the light input by the light source into N sub-light sources and transmit each sub-light source to each of the optical sensor chips, and each of the first photodetectors and each of the second photodetectors are installed corresponding to each of the optical sensor chips, and each of the first photodetectors and each of the second photodetectors are used to detect the photoelectric signals output by two output ports of each of the optical sensor chips. The beneficial effect is that by installing the optical splitter, the light from one light source can be split into multiple paths, making it easy to perform multiple tests at the same time. [Brief description of the drawings]

[0022] [Figure 1] 1A is a schematic diagram of the three-dimensional structure of an optical sensor chip in one embodiment of the present invention, FIG. 1B is a schematic diagram of the planar structure of an optical sensor chip in one embodiment of the present invention, and FIG. 1C is a schematic diagram of the side structure of an optical sensor chip in one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of polarization rotation and polarization separation when the optical sensor chip in FIG. 1 detects different refractive index analytes. [Diagram 3] 1. (a) is a schematic diagram of the simulation results of the normalized transmitted power of the TM00 and TE00 modes at the through port and the coupled port in FIG. 1 as a function of the refractive index of the top clad layer, respectively; (b) is a schematic diagram of the normalized total transmitted power at the through port and the coupled port as a function of the refractive index of the top clad layer in FIG. 1; and (c) is a schematic diagram of the total transmitted power ratio of the through port and the coupled port in FIG. 1. [Figure 4] 2 is a schematic diagram of a spectrum simulation result of the through port when different samples to be measured are placed on the optical sensor chip in FIG. 1 and have different refractive indices. [Diagram 5] FIG. 4 is a schematic plan view of an optical sensor chip according to another embodiment of the present invention; [Figure 6] FIG. 11 is a schematic plan view of an optical sensor chip according to still another embodiment of the present invention; [Figure 7] FIG. 13 is a schematic plan view of an optical sensor chip according to yet another embodiment of the present invention. [Figure 8] FIG. 13 is a structural schematic diagram of a first polarization rotator in yet another embodiment of the present invention. [Figure 9] FIG. 13 is a structural schematic diagram of a first polarization rotator in yet another embodiment of the present invention. [Figure 10] FIG. 1 is a structural block diagram of an optical sensing system according to an embodiment of the present invention. [Figure 11] FIG. 11 is a structural schematic diagram of an optical splitter and an optical sensor chip in yet another embodiment of the present invention. [Figure 12] FIG. 13 is a structural schematic diagram of an optical splitter and an optical sensor chip integrated in yet another embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings of the present invention. It is clear that the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. All other embodiments obtained based on the embodiments of the present invention without the creative efforts of those skilled in the art are within the scope of protection of the present invention. Unless otherwise defined, technical or scientific terms used herein have the ordinary meanings understood by those skilled in the art. Similar words such as "comprise" used in this specification mean that the elements or things appearing before the word include the elements or things listed after the word, and their equivalents, but do not exclude other elements or things.

[0024] In response to problems existing in the prior art, embodiments of the present invention provide an optical sensor chip and an optical sensing system.

[0025] Fig. 1(a) is a schematic diagram of a three-dimensional structure of an optical sensor chip in one embodiment of the present invention, Fig. 1(b) is a schematic diagram of a planar structure of an optical sensor chip in one embodiment of the present invention, and Fig. 1(c) is a schematic diagram of a side structure of an optical sensor chip in one embodiment of the present invention.

[0026] In some embodiments of the present invention, referring to FIG. 1, an optical sensor chip includes a bottom clad layer 1, a top clad layer 2 stacked on the bottom clad layer 1, and an optical waveguide core 3, the optical waveguide core 3 is disposed between the top clad layer 2 and the bottom clad layer 1, the top clad layer 2 is provided with a hollow portion for accommodating a sample to be measured, and a part of the optical waveguide core 3 is exposed by the hollow portion, the optical waveguide core 3 includes a first polarization rotator 301 and a first polarization separator 4, and a front The first polarization separator 4 includes an input port and two output ports including a through port 401 and a coupling port 402, both for outputting polarized light, the first polarization rotator 301 is arranged on the same line as the first polarization separator 4, the first polarization rotator 301 has a first end and a second end, the second end of the first polarization rotator is connected to the input port of the first polarization separator, and the dimensions of the first polarization rotator 301 gradually increase along the direction from the first end to the second end.

[0027] In some specific embodiments of the present invention, the bottom clad layer 1 is disposed horizontally, the optical waveguide core 3 is disposed horizontally in the left-right direction on the upper side of the bottom clad layer 1, the top clad layer 2 is disposed horizontally on the upper side of the bottom clad layer 1, the top clad layer 2 is coated on the optical waveguide core 3, a rectangular hollow portion is provided in the middle of the top clad layer 2, the length of the hollow portion is smaller than the length of the optical waveguide core 3, and both ends of the optical waveguide core 3 are provided between the top clad layer 2 and the top clad layer 2. and the bottom cladding layer 1, the optical waveguide core 3 includes a first polarization rotator 301 and a first polarization separator 4, the first polarization rotator 301 is gradually increased from a first end to a second end, i.e., the cross-sectional area of ​​the first polarization rotator 3 is gradually increased along the direction from left to right, the optical waveguide core 3 can be made of multiple materials including, but not limited to, silicon and silicon nitride, and the first polarization separator 4 is located on the right side of the first polarization rotator 301. , the input port of the first polarization separator 4 is coupled to the right end of the optical waveguide core 3, so that the first polarization separator 4 can receive the polarized light in the optical waveguide core 3; the two output ports of the first polarization separator 4 are a through port 401 and a coupling port 402, respectively, the through port 401 is gradually smaller from left to right, and the coupling port 402 is set in an arc shape; in a normal case, the polarized light output by the output port of the first polarization separator is a transverse magnetic field TM polarization and a transverse electric field T The through port 401 can separate and output most of the transverse magnetic TM polarized light and a small portion of the transverse magnetic TE polarized light from the light output by the first polarization rotator 301, i.e., the through port 401 mainly outputs the transverse magnetic TM polarized light, and the coupled port 402 can separate and output most of the transverse magnetic TE polarized light and a small portion of the transverse magnetic TM polarized light from the light output by the first polarization rotator 301, i.e., the coupled port 402 mainly outputs the transverse magnetic TE polarized light. TE wave: There is a magnetic field component in the propagation direction but no electric field component, and it is called a transverse electric wave, and TM wave: There is an electric field component in the propagation direction but no magnetic field component, and it is called a transverse magnetic wave.

[0028] In use, an analyte to be measured is added to the hollow space, and the analyte is allowed to make sufficient contact with the outer wall of the optical waveguide core 3, specifically, with the outer wall of the first polarization rotator 301; in a normal case, the top clad layer 2 and the bottom clad layer 1 are made of silicon material, and light is input to the left side of the optical waveguide core 3, and photons propagate along the optical waveguide core 3 to the right. When passing through the hollow space, the refractive index of the analyte fluid and the clad layer is different, destroying the vertical symmetry of propagation, thus further shifting the polarization rotation of the light in the optical waveguide core 3 of the hollow space; specifically, the light input from the first end is in the fundamental TM (TM00) mode, and the light input from the second end is in the fundamental TM (TM00) mode. After passing through the points, the output light is fully or partially converted to TE01 mode and output to the coupling port 402 as the fundamental TE (TE00) mode, and the remaining TM00 that is not completely converted is still output to the through port 401 in the fundamental TM mode, that is, the polarized light continues to move to the right along with the first polarization rotator 301 to the first polarization separator 4, and the through port 401 and the coupling port 402 respectively separate and output the TM polarization and TE polarization of the light output by the first polarization rotator 301, and the material information of the analyte to be measured or the information of the biological / chemical target concentration can be tracked based on the output TM polarization and TE polarization.

[0029] The polarization rotation is due to the difference in refractive index between the top clad layer 2 and bottom clad layer 1 in the hollow space, and the sample to be measured. Usually, the top clad layer 2 and the bottom clad layer 1 are made of the same material. In this way, the polarization rotation is due to the difference in refractive index between the analyte to be measured in the hollow space and the clad layers, and information such as the organism, material, components, temperature, and condition of the sample to be measured can be more accurately detected.

[0030] The optical sensor chip of the present application is based on a polarization rotation and separation mechanism, which, unlike existing interferometer and resonator structures for measuring wavelength shifts, eliminates the need and dependency on tunable lasers and is low cost.

[0031] In order for the optical sensor chip to operate normally, the polarization of the light input by the first port is designed as the fundamental TM (TM00), and the evanescent field of the mode extends perpendicularly to the top clad layer 2 and the bottom clad layer 1. When the mode propagates along the optical waveguide core 3 to the hollow space, the evanescent field of the mode interacts with the material in the top clad layer 2. When the hollow space is filled with different concentrations of biological or chemical targets, the refractive index will be different, which will lead to a change in the effective refractive index of the optical mode.

[0032] The hollow portion may also be configured as any other shape, as long as it ensures that the analyte can contact the optical waveguide core 3 .

[0033] FIG. 2 is a schematic diagram of polarization rotation and polarization separation when the optical sensor chip in FIG. 1 detects different refractive index analytes.

[0034] When the hollow space has a certain refractive index, the TM mode can be converted to the TE mode to different degrees, where the refractive index is denoted by nclad. Referring to the simulation mode transition plan view in FIG. 2(a), when the hollow space is filled with air, nclad=1, the light will exit in TE00 mode at the coupling port 402, and there will be practically no TM light exiting at the through port 401. Referring to the simulation mode transition plan views in FIG. 2(b)-(f), when water (with a refractive index of about 1.33) or any other biological or chemical target (with a different refractive index) is added to the hollow space, the rotation from TM00 to TE01 is incomplete, i.e., some light at the coupling port 402 will exit in TE00 mode, and other part light at the through port 401 will still exit in TM00 mode. As shown in FIG. 2, with the increase in the refractive index of the material added to the hollow space, more light will exit at the through port 401, and less light will exit at the coupling port 402.

[0035] Also, the length of the hollow portion can be appropriately selected so that, in use, when no object to be measured is added to the top clad layer 2, there is a complete rotation from the TM00 mode to the TE01 mode.

[0036] In addition, the nclads shown in (a)-(f) in Figure 2 above are only examples and vary from 1 to 1.5. In actual use, the refractive index value may be any value depending on the sample to be measured that is added.

[0037] FIG. 3(a) is a schematic diagram of the simulation results of the normalized transmitted power of the TM00 and TE00 modes at the through port and the coupled port as a function of the refractive index of the top clad layer, respectively, in FIG. 1. FIG. 3(b) is a schematic diagram of the normalized total transmitted power at the through port and the coupled port as a function of the refractive index of the top clad layer in FIG. 1. FIG. 3(c) is a schematic diagram of the total transmitted power ratio of the through port and the coupled port in FIG. 1. Marks in Fig. 3: Top cladding refractive index, Transmission power, Through port 401 (Bar), Coupling port 402 (Cross), Ratio of transmission power, Total power, i.e., the sum of the power of TM00 and TE00 modes, The ratio of transmission power is in dB. With reference to Figs. 1 and 3, when the refractive index of the material in the top cladding layer 2 changes, the transmission power ratio changes within a wide range, for example, when the refractive index goes from 1 to 1.65, the ratio goes from -24 dB to +24 dB. By performing calibration, the measured ratio can be converted into the refractive index of a test sample added to the hollow part of the optical sensor chip, and the characteristics of the test sample can be further estimated.

[0038] FIG. 4 is a schematic diagram of a spectrum simulation result of the through port when different samples to be measured are placed on the optical sensor chip in FIG. 1 and have different refractive indices. Referring to FIG. 4, it can be seen that the design optimization enables the sensor to operate normally within a wide wavelength range, that is, the transmission power basically does not change with the change in the wavelength of light; further, it can be seen that the optical sensor chip of the present application has a wide spectral range of light available, and the transmission power has low dependence on light.

[0039] Also, referring to FIG. 1 and FIG. 4, it can be seen that the peak value transmission power is 90%, not 100%. This is because the refractive index of the cladding layer changes suddenly at the air / silicon oxide interface at the boundary of the hollow section, resulting in extra optical loss. The refractive index of the top cladding layer in the sensor area is different, and the refractive index contrast at the interface will result in different losses. However, such extra optical loss does not affect the detection result, because the sensing signal is not obtained by detecting the absolute power of each port of the two output ports, but by detecting the loss difference between the signals of the through port 401 and the coupled port 402. The loss occurs before the power distribution between the through port 401 and the coupled port 402, so the amount of loss between the through port 401 and the coupled port 402 is the same.

[0040] Also, in some cases, water absorption in some wavelength ranges may affect the performance of existing photonics biosensors, but the optical sensor chip of the present application can offset the loss caused by water absorption by extracting the loss difference between the signals of the through port 401 and the coupling port 402. Therefore, the photonics biosensor of the present application is robust against the water absorption problem.

[0041] FIG. 5 is a schematic plan view of an optical sensor chip according to another embodiment of the present invention.

[0042] In some embodiments of the present invention, referring to FIG. 5 , the optical waveguide core 3 further includes a second polarization rotator 302 and a second polarization separator 5, the second polarization separator 5 and the second polarization rotator 302 are both arranged on the same line as the first polarization rotator 301, the second polarization rotator 302 is arranged between the second polarization separator 5 and the first polarization rotator 301, the second polarization separator 5 includes two input ports including a through input port 501 and a coupled input port 502, and one output port, and the second polarization separator an output port of the second polarization rotator 302 connected to an input port of the first polarization rotator 301; a combined input port 502 of the second polarization separator 5 is used to transmit the input transverse electric field TE polarized light to the second polarization rotator 302; the second polarization rotator 302 is used to convert the transverse electric field TE polarized light into transverse magnetic field TM polarized light; and an output port of the second polarization separator 5 is used to input the transverse magnetic field TM polarized light to the first polarization rotator 301.

[0043] In some specific embodiments of the present invention, the second polarization separator 5 has the same structure as the first polarization separator 4 and is installed symmetrically, and the second polarization rotator 302 is installed between the second polarization separator 5 and the first polarization rotator 301, the second polarization separator 5 is coupled to the left end of the second polarization rotator 302, and the right end of the second polarization rotator 302 is coupled to the left end of the first polarization rotator 301. In a normal case, the light required to be input to the optical sensor chip has TM polarization, and most of the light having TE polarization cannot be directly used. By installing the second polarization separator 5 and the second polarization rotator 302, the light having TE polarization can be input from the combined input port 502 and converted to TM polarization before entering the first polarization rotator 301, which is easy to use in practice.

[0044] In some embodiments of the present invention, referring to Fig. 1, the structure shape of the first polarization rotator 301 is a tapered shape or a wedge shape. In some specific embodiments of the present invention, the structure shape of the first polarization rotator 301 is a tapered shape, i.e., the cross-sectional area of ​​the first polarization rotator 301 increases sequentially from left to right.

[0045] FIG. 6 is a schematic plan view of an optical sensor chip according to still another embodiment of the present invention.

[0046] 1 and 6, in some embodiments of the present invention, the optical waveguide cores 3 are arranged in a plurality of parallel configurations, and the optical waveguide cores 3 are arranged in a plurality of parallel configurations. Specifically, the first polarization rotator 301 and the first polarization separator 4 are arranged in a plurality of parallel configurations.

[0047] In addition, when a plurality of the first polarization rotators 301 and the first polarization separators 4 are installed, the installation directions of each of the first polarization rotators 301 and the first polarization separators 4 can be adjusted as necessary.

[0048] FIG. 7 is a schematic plan view of the structure of an optical sensor chip according to still another embodiment of the present invention.

[0049] In some embodiments of the present invention, referring to FIG. 5 and FIG. 7, the first polarization rotator 301, the first polarization separator 4, the second polarization rotator 302 and the second polarization separator 5 are all three arranged in parallel.

[0050] FIG. 8 is a structural schematic diagram of a first polarization rotator in yet another embodiment of the present invention.

[0051] In some embodiments of the present invention, referring to Figures 1 and 8, the first polarization rotator 301 is spatially arranged in a spiral manner.

[0052] FIG. 9 is a structural schematic diagram of a first polarization rotator in yet another embodiment of the present invention.

[0053] In some embodiments of the present invention, referring to Figs. 1 and 9, the first polarization rotator 301 is arranged in a spatially folded manner.

[0054] In addition, the first polarization rotator 301 may be configured in a spiral shape or a folded shape, and the cross-sectional area of ​​the first polarization rotator 301 is configured to gradually increase along the path.

[0055] In some embodiments of the present invention, referring to FIG. 5 , the first polarization separator 4 includes any one of a directional coupler, an adiabatic coupler, a bent coupler, a Y-shaped separator, a multimode interferometer, a photonic crystal, a grating and a prism, and the second polarization separator 5 includes any one of a directional coupler, an adiabatic coupler, a bent coupler, a Y-shaped separator, a multimode interferometer, a photonic crystal, a grating and a prism.

[0056] In some embodiments of the present invention, and referring to FIG. 1, the optical waveguide core 3 is made from at least one of silicon, silicon nitride, silica, alumina, lithium niobate, or III-V materials.

[0057] In some embodiments of the present invention, referring to FIG. 1, the optical waveguide core 3 is made of a sub-wavelength structure.

[0058] FIG. 10 is a structural block diagram of an optical sensing system in one embodiment of the present invention.

[0059] In some embodiments of the present invention, referring to FIG. 1 and FIG. 10, the optical sensor chip 12 includes a light source 6, a first photodetector 7, a second photodetector 8, a power source (not shown), a controller 10, a display 9, a flow controller 11, and the optical sensor chip 12 according to any one of the above embodiments, the light source 6 is used to input the light source 6 to one end of the optical sensor chip 12, the first photodetector 7 and the second photodetector 8 are installed at the other end of the optical sensor chip 12, the first photodetector 7 and the second photodetector 8 are used to detect the photoelectric signal output by the two output ports of the optical sensor chip 12, the display 9 is electrically connected to the first photodetector 7 and the second photodetector 8 respectively, the first photodetector 7 and the second photodetector 8 convey the photoelectric signal to the display 9, and the display 9 is connected to the optical sensor chip 12 to detect the photoelectric signal. a first optical detector 7, a second optical detector 8, and a flow controller 11, which receives and displays a signal from the first optical detector 7, ...

[0060] In some specific embodiments of the present invention, the light source 6 is installed on the left side of the optical sensor chip 12, the light source 6 and the optical waveguide core 3 are installed opposite to each other, and light is input to the optical sensor chip 12 by the light source 6; the first photodetector 7 and the second photodetector 8 are installed on the right side of the optical sensor chip 12, the first photodetector 7 is installed in opposition to the through port 401, and the second photodetector 8 is installed in opposition to the coupling port 402; the first photodetector 7 and the second photodetector 8 respectively detect the TM and TE optical signals output by the two output ports of the first polarization separator 4; and the first photodetector 7 and the second photodetector 8 transmit the detected optical signals to the display 9 for display and easy observation; Two flow paths are provided in the row controller 11, the left end of one flow path is connected to the analyte to be measured, and the other end is connected to the hollow space of the optical sensor chip 12, the left end of the other flow path is connected to the hollow space of the optical sensor chip 12, and the other end extends and connects to the outside, and a drive is provided in each of the two flow paths, and the analyte to be measured can be added to the optical sensor chip 12 from the front passage by the flow controller 11 and output through the rear one flow path, the controller 10 is electrically connected to the light source 6, the first photodetector 7, the second photodetector 8 and the flow controller 11, and a power source (not shown) is electrically connected to the controller 10, the light source 6, the first photodetector 7, the second photodetector 8 and the flow controller 11, respectively.

[0061] During use, the controller 10 controls the on-state of the light source 6, inputs light into the optical sensor chip 12, the controller 10 controls the on-state of the flow controller 11, adds an analyte to the optical sensor chip 12, controls the on-state of the first photodetector 7 and the second photodetector 8 to detect the output optical signal, and further tracks and analyzes the analyte. In addition, the analyte is added sequentially to the front and rear by the flow controller 11, and the optical signals for different analytes are collected, so that different analytes can be detected and analyzed in one operation.

[0062] In some embodiments of the present invention, referring to Figures 1 and 10, at least one of the light source 6, the first photodetector 7 and the second photodetector 8 are integrated into the optical sensor chip 12.

[0063] In some specific embodiments of the present invention, the light source 6 , the first photodetector 7 and the second photodetector 8 are all integrated into the optical sensor chip 12 .

[0064] The integration methods of the light source 6 include directly butt-bonding the light source 6 to the optical sensor chip 12, placing the light source 6 in a cavity formed on the optical sensor chip 12, hetero-integrating the light source 6 with the optical sensor chip 12, and connecting the light source 6 and the optical sensor chip 12 using optical fiber or photonic wire bonding.

[0065] 1 and 10, in some embodiments of the present invention, the light source 6 is a fixed wavelength light source or a broadband light source, and the light source 6 is any one of a distributed feedback laser, a vertical cavity surface emitting laser, a superluminescent diode, and a light emitting diode. The wavelength range of the light source 6 includes any one of visible light, O-band light, C-band light, and mid-infrared light.

[0066] In some specific embodiments of the present invention, the optical sensor chip 12 does not need to rely on the fine resolution wavelength scanning of a narrow linewidth laser, so the light source can be a fixed wavelength light source or a broadband light source, such as a distributed feedback laser, a vertical cavity surface emitting laser, a superluminescent diode or a light emitting diode, and can be in the visible, O-band, C-band or mid-infrared wavelength range, thus significantly reducing the cost of the light source 6.

[0067] In addition, in actual use, the light source may be set as a tunable light source.

[0068] FIG. 11 is a structural schematic diagram of an optical splitter and an optical sensor chip in yet another embodiment of the present invention.

[0069] In some embodiments of the present invention, referring to Figures 10 and 11, the first photodetector 7, the second photodetector 8 and the optical sensor chip 12 are all installed in a number N (N is a positive integer), the optical sensing system further includes an optical splitter 13, the optical splitter 13 is installed between the light source 6 and the optical sensor chip 12, the optical splitter 12 is used to split the light input by the light source 6 into N sub-light sources and transmit each sub-light source to each of the optical sensor chips 12, each of the first photodetectors 7 and each of the second photodetectors 8 is installed corresponding to each of the optical sensor chips 12, and each of the first photodetectors 7 and each of the second photodetectors 8 is used to detect the photoelectric signals output by the two output ports of each of the optical sensor chips 12.

[0070] In some specific embodiments of the present invention, the first photodetector 7, the second photodetector 8 and the optical sensor chip 12 are each installed in eight pieces, the optical splitter 13 is installed on the right side of the light source 6, the optical splitter 13 splits the light input by the light source 6 into eight sub-light sources and transmits the eight sub-light sources to the eight optical sensor chips 12, and the eight first photodetectors 7 and the eight second photodetectors 8 are installed corresponding to the eight optical sensor chips 12, respectively, and detect the optical signals output by the eight optical sensor chips 12 and transmit them to the display 9.

[0071] In addition, the number of the first photodetectors 7, the second photodetectors 8, the optical sensor chips 12, and the number of sub-light sources divided by the optical splitter 13 can be set to any value according to actual needs, and can be installed corresponding to each other.

[0072] FIG. 12 is a structural schematic diagram of an optical splitter and an optical sensor chip integrated in yet another embodiment of the present invention.

[0073] 10 and 12, in some embodiments of the present invention, the optical splitter 13 and the plurality of optical sensor chips 12 are integrated together. In practical use, the optical splitter 13, the plurality of optical sensor chips 12 and the corresponding spectroscopic paths of each sensor chip are integrated together, which is convenient for use.

[0074] During fabrication, the optical sensors and the optical splitter can be directly and integrally molded onto the chip, eliminating the need for a subsequent integration step.

[0075] Although the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and changes to these embodiments are possible. However, it should be understood that such modifications and changes are within the scope and spirit of the present invention as defined in the appended claims. In addition, the present invention described herein may have other embodiments and may be implemented or realized in various ways. [Explanation of symbols]

[0076] 1 Bottom Clad Layer 2 Top Clad Layer 3 Optical waveguide core 301 First polarization rotator 302 Second Polarization Rotator 4. First Polarization Separator 401 Through Port 402 bonded port 5 Second Polarization Separator 501 Thru input port 502 Combined Input Ports 6 light source 7 First Photodetector 8 Second Photodetector 9. Display 10 Controller 11 Flow Controller 12 Optical sensor chip 13 Optical splitter

Claims

1. An optical sensor chip including a bottom clad layer, a top clad layer stacked on the bottom clad layer, and an optical waveguide core, the optical waveguide core is disposed between the top clad layer and the bottom clad layer, the top clad layer is provided with a hollow portion for accommodating a sample to be measured, and a part of the optical waveguide core is exposed by the hollow portion; the optical waveguide core includes a first polarization rotator and a first polarization separator; The first polarization separator includes an input port and two output ports including a through port for outputting mainly transverse magnetic TM-polarized light and a coupling port for outputting mainly transverse electric TE-polarized light; the first polarization rotator is collinear with the first polarization separator, the first polarization rotator has a first end and a second end, the second end of the first polarization rotator communicates with an input port of the first polarization separator, and a dimension of the first polarization rotator gradually increases along a direction from the first end to the second end; 1. An optical sensor chip comprising:

2. the optical waveguide core further includes a second polarization rotator and a second polarization separator; the second polarization separator and the second polarization rotator are both arranged on the same line as the first polarization rotator, the second polarization rotator is arranged between the second polarization separator and the first polarization rotator, the second polarization separator includes two input ports including a through input port and a combined input port, and one output port, the output port of the second polarization separator is connected to the input port of the second polarization rotator, and the output port of the second polarization rotator is connected to the input port of the first polarization rotator; a coupling input port of the second polarization separator is used to transmit the input transverse electric TE polarized light to the second polarization rotator, the second polarization rotator is used to convert the transverse electric TE polarized light to transverse magnetic TM polarized light, and an output port of the second polarization rotator is used to input the transverse magnetic TM polarized light to the first polarization rotator; 2. The optical sensor chip according to claim 1.

3. The structural shape of the first polarization rotator is a tapered shape or a wedge shape.

3. The optical sensor chip according to claim 1 or 2.

4. The optical waveguide core is spatially arranged in a spiral or folded shape; 3. The optical sensor chip according to claim 1 or 2.

5. The first polarization separator includes any one of a directional coupler, an adiabatic coupler, a bent coupler, a Y-shaped separator, a multimode interferometer, a photonic crystal, a grating, and a prism, and the second polarization separator includes any one of a directional coupler, an adiabatic coupler, a bent coupler, a Y-shaped separator, a multimode interferometer, a photonic crystal, a grating, and a prism.

3. The optical sensor chip according to claim 2.

6. The optical waveguide core is made of at least one of silicon, silicon nitride, silica, alumina, lithium niobate, and III-V materials.

3. The optical sensor chip according to claim 1 or 2.

7. The optical waveguide core is made of a sub-wavelength structure.

3. The optical sensor chip according to claim 1 or 2.

8. A plurality of the optical waveguide cores are provided, and each of the optical waveguide cores is provided between the top clad layer and the bottom clad layer.

3. The optical sensor chip according to claim 1 or 2.

9. The optical sensor chip is applied to at least one of biological sensing, gas sensing, temperature sensing, humidity sensing, odor sensing, chemical sensing, water quality monitoring, and greenhouse monitoring; 3. The optical sensor chip according to claim 1 or 2.

10. An optical sensing system comprising a light source, a first photodetector, a second photodetector, a power source, a controller, a display, a flow controller, and the optical sensor chip according to any one of claims 1 to 7, The light source is used to input light to one end of the optical sensor chip; the first photodetector and the second photodetector are disposed at another end of the optical sensor chip, and the first photodetector and the second photodetector are used to detect photoelectric signals outputted by two output ports of the optical sensor chip; the display is electrically connected to the first photodetector and the second photodetector, respectively, the first photodetector and the second photodetector convey the photoelectric signal to the display, and the display receives and displays the photoelectric signal; The flow controller is provided with an output interface and an input interface, both of which are connected to the hollow portion of the optical waveguide core, and the flow controller is used to transport the biological sample to be measured, and the flow controller is used to transport the biological sample to be measured to the hollow portion by the output interface and to collect the biological sample to be measured from the hollow portion by the output interface; the controller is electrically connected to the light source, the first photodetector, the second photodetector and the flow controller, respectively, and the controller is used to control opening and closing of the light source, the first photodetector, the second photodetector and the flow controller, respectively; An optical sensing system comprising:

11. At least one of the light source, the first photodetector, and the second photodetector is integrally disposed on the optical sensor chip.

11. The optical sensing system of claim 10.

12. The light source is a fixed wavelength light source or a broadband light source.

11. The optical sensing system of claim 10.

13. The light source is one of a distributed feedback laser, a vertical cavity surface emitting laser, a superluminescent diode, and a light emitting diode; 11. The optical sensing system of claim 10.

14. The wavelength range of the light source includes any one of visible light, O-band light, C-band light, and mid-infrared light; 11. The optical sensing system of claim 10.

15. The first photodetector, the second photodetector, and the optical sensor chip are each provided in a number N (N is a positive integer), the optical sensing system further comprising an optical splitter; The optical splitter is installed between the light source and the optical sensor chip, and the optical splitter is used to split the light input by the light source into N sub-light sources and transmit the sub-light sources of each section to each of the optical sensor chips, respectively; each of the first photodetectors and each of the second photodetectors is installed corresponding to each of the optical sensor chips, and each of the first photodetectors and each of the second photodetectors is used to detect photoelectric signals output by two output ports of each of the optical sensor chips, respectively.

15. The optical sensing system according to any one of claims 10 to 14.

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