Multi-parameter quantum sensing light quantum chip and preparation method and application thereof

Abstract

The invention discloses a multi-parameter quantum sensing light quantum chip and a preparation method and application thereof, and relates to the fields of quantum information technology, photoelectron technology and nonlinear optics. The light quantum chip provided by the invention comprises a substrate and a light path arranged on the substrate, the light path comprises a classical laser processing unit, a nonlinear unit, a sensing unit and a quantum state output unit which are connected; the nonlinear unit comprises a first entangled photon pair generation waveguide and a second entangled photon pair generation waveguide which are arranged in parallel; the sensing unit comprises a reference arm waveguide and a sensing arm waveguide; and the quantum state output unit comprises a third beam splitter communicated with the reference arm and the sensing arm. According to the light quantum chip provided by the invention, the sensitivity, the precision, the spatial resolution, the expansibility, the integration level and the stability of light quantum sensing can be remarkably improved. The invention also provides a preparation method and application of the light quantum sensor.

Description

Technical Field

[0001] The present invention relates to the fields of quantum information technology, optoelectronic technology and nonlinear optics, and in particular to a multi-parameter quantum sensing photon chip and a preparation method and application thereof. Background Art

[0002] Due to the classical shot noise limit, when a physical measurement is repeated N times, its final standard deviation will converge to Quantum sensing and precision measurement, with the help of quantum entanglement or particle coherence, can achieve an uncertainty of up to the Heisenberg limit (1 / N) under a suitable measurement basis, which will exceed the accuracy of the classical statistical limit. In optical systems, quantum sensing and precision measurement based on continuous and discrete variables have shown theoretical and experimental superiority. Integrated optics integrates discrete components in bulk optical paths onto a chip, which is very compact, has enhanced scalability, programmable configuration, and the entire system is more stable, which can accelerate the practical application of optical quantum sensing and precision measurement technology. The main functional structure of optical quantum chips includes integrated quantum light sources, optical quantum information processing circuits, and optical quantum state detection. Integrated quantum light sources are generally prepared through spontaneous nonlinear processes, such as spontaneous parametric down-conversion based on second-order nonlinearity and spontaneous four-wave mixing effects based on third-order nonlinearity to generate time-correlated photon pair sources and various types of entangled sources. Integrated optical quantum information processing circuits are generally implemented based on linear optical networks, such as optical waveguides, Mach-Zehnder interferometers, etc. Silicon has a large third-order nonlinear coefficient, and the processing of silicon chips is compatible with CMOS technology. In addition, the chip can be configured using the thermo-optical effect. Therefore, silicon chips have the advantages of low cost and mass production, which is conducive to the development of large-scale, highly integrated photonic quantum chips. In addition, materials such as silicon nitride, aluminum gallium arsenide, silicon dioxide and lithium niobate are also used in photonic quantum chips.

[0003] However, the current optical quantum sensing and precision measurement technology is mainly based on platform optics, which is not stable, does not have good functional expansion and programmability, and is not conducive to the miniaturization of the system. Therefore, there is a lack of optical quantum chip configuration solutions for quantum sensing and precision measurement technology. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems and provide a photonic quantum chip for multi-parameter quantum sensing, which can significantly improve the sensitivity, accuracy, spatial resolution, scalability, integration, stability, etc. of quantum sensing.

[0005] The present invention also provides a method for preparing the above-mentioned photon quantum chip.

[0006] The present invention also provides applications of the above-mentioned photon quantum chip.

[0007] According to an embodiment of the first aspect of the present invention, there is provided a photon chip for multi-parameter quantum sensing, the photon chip for multi-parameter quantum sensing comprising a substrate, and an optical path arranged on the substrate;

[0008] The optical path includes a classical laser processing unit, a nonlinear unit, a sensing unit and a quantum state output unit which are connected and arranged;

[0009] The classical laser processing unit comprises a first beam splitter connected in connection, a first waveguide and a second waveguide connected in parallel, and a second beam splitter; a first phase shifter is arranged on the first waveguide; and a second phase shifter is arranged on the second waveguide;

[0010] The nonlinear unit includes a first entangled photon pair generating waveguide and a second entangled photon pair generating waveguide connected to the second beam splitter and arranged in parallel;

[0011] The sensing unit comprises a reference arm connected to the waveguide generating the first entangled photon pair, and a sensing arm connected to the waveguide generating the second entangled photon pair;

[0012] The quantum state output unit includes a third beam splitter connected to the reference arm and the sensor arm.

[0013] The operating mechanism of the photon chip provided by the present invention is as follows:

[0014] The classical laser processing unit can be regarded as a Mach-Zehnder interferometer, including two fixed-ratio beam splitters and an adjustable phase shifter, which can realize beam splitting and phase modulation of the pump light. Specifically: the two beams of light obtained after the pump laser passes through the first beam splitter are input into the first waveguide and the second waveguide respectively; and the phase difference between the two pump lights is adjusted through the first phase shifter and the second phase shifter arranged thereon; then the two pump lights are converged through the second beam splitter and continue to be split.

[0015] The entangled photon generation process occurs in the nonlinear unit. Based on the spontaneous four-wave mixing effect of the third-order nonlinearity or the parametric down-conversion process of the second-order nonlinearity, the photon pairs are generated from the upper optical path or the lower optical path to form a path bunching state.

[0016] The processing of entangled photons in the sensing unit is to convert the physical quantity to be measured into the phase information of the optical path on the sensing arm, thereby regulating the light quantum state; the quantum state output unit is used to realize quantum state interference, obtain multiple quantum state outputs, and then measure by selecting a suitable projection measurement basis. Specifically, the sensing unit controls the phase difference φ of the bunching state through the sensing parameter, and realizes the interference of entangled photons on the third beam splitter; the two-photon path bunching state For example, if the path bunching state generated by the nonlinear unit has the same phase in the upper and lower optical paths after passing through the sensing area, then the bunching state will be separated after HOM interference (the third beam splitter), that is, For the general path bunching state with phase difference φ, the superposition of the separated state and the bunching state is obtained after interference, that is,

[0017]

[0018] The control method according to the embodiment of the present invention has at least the following beneficial effects:

[0019] The photon chip provided by the present invention can detect physical parameters such as temperature, solution concentration, humidity, gas concentration, electric field, etc. through the combination and coordination between various units; and has the characteristics of high sensitivity, high precision, high integration, high spatial resolution, miniaturization, good stability, portability, and configurability. Specifically:

[0020] (1) On the optical quantum chip, due to the setting of the classical laser processing unit and the nonlinear unit and the limitation of the special form, the quantum light source is easy to realize, the preparation of the 2-photon bunching state based on path coding is relatively simple, and the control of the quantum state can be realized by the phase shifter and other components in the classical laser unit;

[0021] (2) The optical quantum chip includes the sensing unit and the quantum state output unit, and can realize quantum sensing parameter measurement with double phase sensitivity by using two-photon HOM interference; not limited to 2 photons, 4 photons, 6 photons and more photons can realize higher phase sensitivity measurement by bunched quantum states;

[0022] (3) The photon quantum chip can realize multi-parameter quantum sensing. The sensing unit can be used to sense changes in physical parameters such as temperature, refractive index concentration, humidity, gas concentration and electric field, thereby realizing multiple sensing functions on the same photon quantum chip.

[0023] According to some embodiments of the present invention, the optical quantum chip further comprises a covering layer and a buried layer. The buried layer is disposed on the surface of the substrate, the optical path is located above the buried layer, and the covering layer covers the optical path.

[0024] According to some embodiments of the present invention, the material of the buried layer includes silicon dioxide.

[0025] According to some embodiments of the present invention, the maximum thickness of the buried layer is 2.5-3.5 μm; for example, it may be about 3 μm.

[0026] According to some embodiments of the present invention, the material of the covering layer includes silicon dioxide.

[0027] According to some embodiments of the present invention, the maximum thickness of the covering layer is 2.5-3.5 μm; for example, it may be about 3 μm.

[0028] According to some embodiments of the present invention, the photon chip further includes at least one input port, and the input port is connected to the first beam splitter. In actual operation, as long as one input port operates stably, the photon chip can operate normally; in order to further improve the operation stability of the photon chip, two input ports are provided thereon as above.

[0029] According to some embodiments of the present invention, the photon chip further comprises an optical fiber array. During use, the pump light enters the input port through the optical fiber array, and finally couples out of the photon chip through the first output port and the second output port.

[0030] According to some embodiments of the present invention, the first beam splitter is a 2×2 beam splitter.

[0031] According to some embodiments of the present invention, the second beam splitter is a 2×2 beam splitter.

[0032] According to some embodiments of the present invention, the second beam splitter and the first entangled photon pair generating waveguide are connected via a third waveguide.

[0033] According to some embodiments of the present invention, the second beam splitter and the second entangled photon pair generating waveguide are connected by a fourth waveguide.

[0034] It can be understood that the first entangled photon pair generating waveguide and the second entangled photon pair generating waveguide are both mosquito coil type waveguides.

[0035] According to some embodiments of the present invention, the material of the nonlinear unit includes at least one of a third-order nonlinear waveguide material or a second-order nonlinear waveguide material; the specific material selection includes at least one of silicon, silicon nitride, aluminum gallium arsenide, silicon dioxide and lithium niobate. Therefore, the process of converting the upper and lower pump lights into degenerate entangled photon pairs can rely on the spontaneous four-wave mixing effect of the third-order nonlinear waveguide material or the spontaneous parametric down-conversion effect of the second-order nonlinear waveguide material.

[0036] According to some embodiments of the present invention, a third phase shifter is provided on the reference arm.

[0037] The third phase shifter is used to adjust the phase difference of the bunched entangled photon pair generated by the nonlinear unit and set the working point of the sensor.

[0038] The first phase shifter, the second phase shifter and the third phase shifter configure the phase of the optical path by changing the refractive index in the waveguide, and the implementation method is not limited to the thermo-optic effect and the electro-optic effect, and also includes various technologies that can control the phase of the optical path such as the optical Kerr effect.

[0039] According to some embodiments of the present invention, the lengths of the sensing arm and the reference arm are not equal, so that the phase difference caused by temperature can be used to perform temperature sensing test.

[0040] According to some embodiments of the present invention, the sensing arm and the reference arm are of equal length, but a covering layer in a local area of ​​the sensing arm is etched.

[0041] Therefore, the difference in refractive index of different exposed material areas can be used to perform sensing tests on solution, gas concentration, or humidity.

[0042] The key point of the present invention is to set the sensing unit in the optical path, the sensing unit includes the reference arm and the sensing arm, and the phases of the two arms can be adjusted by the third phase shifter and the optical path phase of the physical quantity to be measured on the sensing arm, thereby regulating the phase difference of the bunched state entangled photon pair and realizing multiple phase-sensitive quantum sensing parameter measurement. Among them, the optical path phase adjustment of the physical quantity on the sensing arm is mainly the influence of the physical quantity on the refractive index of the sensing arm (or its local area).

[0043] According to some embodiments of the present invention, the third beam splitter is a 50:50 beam splitter (splitting the incident light in a 1:1 ratio), on which quantum interference occurs, and multiple quantum state outputs are obtained, which are then measured by selecting a suitable projection measurement basis.

[0044] According to some embodiments of the present invention, the beam splitter is equivalent to a waveguide interferometer, which can adjust the generated entangled photon state, and the waveguide interferometer includes at least one of a HOM interferometer, a Mach-Zehnder interferometer, a Michelson interferometer or a Franson interferometer.

[0045] According to some embodiments of the present invention, the quantum state output unit further includes a fifth waveguide, a sixth waveguide, a bend waveguide and a straight waveguide.

[0046] According to some embodiments of the present invention, the photon chip further includes at least two output ports; the output ports are connected to the third beam splitter.

[0047] The third beam splitter obtains two beams of light, one of which is output from the photon chip via the fifth waveguide, the bend waveguide and the output port in sequence; the other is output from the photon chip via the sixth waveguide, the straight waveguide and the output port in sequence.

[0048] The quantum state outputted through the output port can be subjected to projection measurement.

[0049] According to some embodiments of the present invention, the photon quantum chip can realize multiple phase-sensitive physical parameter sensing for 2-photon, 4-photon, 6-photon and more photon bunching states. Taking the 2-photon bunching state as an example, by adjusting the two-photon path entanglement state through two-photon HOM interference, a 2-fold phase-sensitive quantum sensing parameter measurement can be obtained, and the sensing accuracy can exceed the classical shot noise limit. The sensing sensitivity of n-photon bunching states with a photon number greater than 2 can reach n times that of its classical process.

[0050] According to an embodiment of the second aspect of the present invention, a method for preparing the photonic quantum chip is provided, the method comprising arranging the optical path on the substrate.

[0051] Since the preparation method adopts all the technical solutions of the optical quantum chip of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0052] The preparation method is a standard micro-nano processing technology, including steps such as preparing a silicon substrate, photolithography chip structure, etching waveguides, preparing a silicon dioxide buried layer, and making metal electrodes. Among them, the photolithography chip structure and the etching waveguide are used to form the optical path; further, the setting method of the optical path includes at least one of a photolithography method, an electron beam exposure method, a chemical exchange method, a mechanical cutting method, and a chemical mechanical polishing method. It should be noted that in the processing of the photon chip, the order of the above steps can be adjusted forward and backward, and those skilled in the art can select appropriate parameters, methods, and step order based on their operating experience and with reference to the specific structure of the photon chip.

[0053] According to an embodiment of the third aspect of the present invention, there is provided an application of the photonic quantum chip in temperature, solution concentration, humidity, gas concentration and electric field testing.

[0054] Since the application adopts all the technical solutions of the optical quantum chip of the above-mentioned embodiment, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment.

[0055] If there is no special explanation, the actual meaning of “about” in the present invention is that the error is allowed to be within the range of ±2%, for example, about 100 is actually 100±2%×100.

[0056] Unless otherwise specified, “between” in the present invention includes the number itself, for example, “between 2 and 3” includes the endpoint values ​​2 and 3.

[0057] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the structure of the present invention;

[0059] Figure 2 is the temperature sensing calculation given in Example 1 of the present invention;

[0060] Figure 3 is the solution concentration sensing calculation given in Example 2 of the present invention;

[0061] Figure 4 is the air humidity sensing calculation given in Example 3 of the present invention;

[0062] Figure 5 It is a schematic cross-sectional view of the waveguide in the photonic quantum chip in Examples 1 to 3 of the present invention.

[0063] Reference numerals:

[0064] Pump light 1;

[0065] Optical fiber array 2;

[0066] A first input port 4, a second input port 5;

[0067] A first beam splitter 7, a first waveguide 8, a second waveguide 9, a first phase shifter 10, a second phase shifter 11, and a second beam splitter 12;

[0068] A third waveguide 13, a fourth waveguide 14, a first entangled photon pair generating waveguide 15, and a second entangled photon pair generating waveguide 16;

[0069] Reference arm 17, sensing arm 18, third phase shifter 19;

[0070] A third beam splitter 20, a fifth waveguide 21, and a sixth waveguide 22;

[0071] The first output port 3 and the second output port 6. DETAILED DESCRIPTION

[0072] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0073] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0074] Example 1

[0075] This example provides a photonic quantum chip with multi-parameter quantum sensing based on silicon-based materials, and uses it to perform temperature sensing calculations.

[0076] refer to Figure 1 , the photonic quantum chip provided in this example includes:

[0077] The optical quantum chip for multi-parameter quantum sensing includes a substrate and an optical path arranged on the substrate;

[0078] The optical path includes an input port, a classical laser processing unit, a nonlinear unit, a sensing unit, a quantum state output unit and an output port connected to each other;

[0079] The input port includes an optical fiber array 2, a first input port 4 and a second input port 5 (one of which is a spare input port); the output port includes a first output port 3 and a second output port 6;

[0080] The classical laser processing unit comprises a first beam splitter 7 connected to the first input port 4 and the second input port 5 at the same time; a first waveguide 8 and a second waveguide 9 connected to the first beam splitter 7 and arranged in parallel, a first phase shifter 10 is arranged on the first waveguide 8, and a second phase shifter 11 is arranged on the second waveguide 9; a second beam splitter 12 connected to the first waveguide 8 and the second waveguide 9 at the same time;

[0081] The nonlinear unit includes a third waveguide 13 and a fourth waveguide 14 connected to the second beam splitter 12; and a first entangled photon pair generating waveguide 15 connected to the third waveguide 13, and a second entangled photon pair generating waveguide 16 connected to the fourth waveguide 14; the lengths of the first entangled photon pair generating waveguide 15 (mosquito-coil type waveguide) and the second entangled photon pair generating waveguide 16 (mosquito-coil type waveguide) are 1 cm respectively.

[0082] The sensing unit includes a reference arm 17 connected to the first entangled photon pair generating waveguide 15, and a sensing arm 18 connected to the second entangled photon pair generating waveguide 16; a third phase shifter 19 is arranged on the reference arm 17; and the arm length difference ΔL of the two arms of the sensing unit is set to 87.964 μm. The arm length difference determines the accuracy and range of the temperature sensing test of the obtained optical quantum chip.

[0083] The quantum state output unit includes a third beam splitter 20 connected to the reference arm 17 and the sensor arm 18; and a fifth waveguide 21 and a sixth waveguide 22 connected to the third beam splitter 20; the fifth waveguide 21 is connected to the first output port 3 via a curved waveguide; and the sixth waveguide 22 is connected to the second output port 6 via a straight waveguide.

[0084] refer to Figure 5 The optical quantum chips provided in this example all use silicon (Si) based waveguides, the cross-sectional width and height of the waveguides are 500nm and 220nm respectively, the cover layer and the buried layer are both 3μm thick silicon dioxide, the substrate is a silicon substrate, and the main body of the waveguide is silicon. The waveguides mentioned here include the first waveguide 8, the second waveguide 9, the third waveguide 13, the fourth waveguide 14, the first entangled photon pair generating waveguide 15, the second entangled photon pair generating waveguide 16; the reference arm 17, the sensor arm 18, the fifth waveguide 21 and the sixth waveguide 22.

[0085] In the photonic quantum chip provided in this example, the size of any beam splitter is 140 μm×40.5 μm; the length of the three phase shifters is 180 μm.

[0086] The preparation method of the photon quantum chip provided in this example is a standard micro-nano processing technology, including the steps of preparing a silicon substrate, photolithography chip structure, etching waveguides, preparing a silicon dioxide buried layer, and making metal electrodes. During use, a continuous pump light 1 with a wavelength of 1549.32nm enters the photon quantum chip through the first input port 4; the working power of the first phase shifter 10 and the second phase shifter 11 is adjusted by a DC power supply to change the phase difference of the first waveguide 8 or the second waveguide 9 (i.e., the two arms of the Mach-Zehnder interferometer), and the π phase power consumption is 25mW; the pump light power is configured to be equally distributed in the third waveguide 13 and the fourth waveguide 14. The wavelengths of the entangled photon pairs output by the first entangled photon pair generating waveguide 15 and the second entangled photon pair generating waveguide 16 are 1546.02nm and 1552.52nm respectively; the half-maximum full width of the generated photon pairs is 54nm.

[0087] The calculation process of temperature sensing is as follows:

[0088] In the sensor unit, the phase difference between the two arms is As the overall temperature T of the sensing unit changes, where λ is the wavelength. represents the change in the effective refractive index n of the silicon waveguide (sensing arm and reference arm) per unit temperature change, and △L is the difference in arm length between the two arms; in the silicon waveguide used in this example, RIU is approximately equal to 1.87×10 -4 ℃ -1 Therefore, when the temperature change reaches 94°C, the phase difference changes by 2π. After passing through the sensing unit, it is phase modulated (third phase shifter 19) and becomes After the 50:50 beam splitter (third beam splitter 20) interference, the output state becomes Two-photon path bunching (produced from the nonlinear unit) passes through the sensing unit and is phase modulated (by the third phase shifter 19) and becomes After the 50:50 beam splitter (third beam splitter 20) interference, the output state becomes

[0089] Therefore, in this example, the use of two-photon path bunching state (produced from nonlinear unit) can achieve temperature sensing with double phase sensitivity. The |11> state is selected as the projection measurement basis to measure the two-photon coincidence counting interference curve. The theoretical calculation value is as follows Figure 2 shown.

[0090] Example 2

[0091] This example provides a multi-parameter quantum sensing photon chip based on silicon-based materials, and uses it to perform sodium chloride solution concentration sensing calculation; the specific difference from Example 1 is:

[0092] In this example of the photonic quantum chip, the lengths of the reference arm 17 and the sensing arm 18 are equal. However, the silicon dioxide covering layer of the silicon waveguide on the sensing arm needs to be etched away and exposed to the air. The etching length L is 300 μm. Without destroying the structure, the longer L is, the higher the sensing accuracy is.

[0093] The process of concentration sensing calculation is as follows:

[0094] In the sensor unit, the phase difference between the two arms is As the concentration m of the sensor unit solution changes, where λ is the wavelength. Represents the change in the refractive index n1 of the solution under a unit concentration change. Taking sodium chloride solution as an example, RIUneff is approximately equal to 0.14585% -1 . It represents the change of the effective refractive index n of the windowed waveguide (sensing arm) when the refractive index n1 of the solution changes. Under the parameters of the silicon waveguide (sensing arm) used in this example, RIUmf is approximately equal to 1.8×10 -3Therefore, when the concentration of the sodium chloride solution changes by 20%, the phase difference changes by 2π. After passing through the sensing unit, it is phase modulated (third phase shifter 19) and becomes After the 50:50 beam splitter (third beam splitter 20) interference, the output state becomes The two-photon path bunching state in this example (produced from the nonlinear unit) passes through the sensing unit and is phase modulated (by the third phase shifter 19) and becomes After the 50:50 beam splitter (third beam splitter 20) interference, the output state becomes

[0095] Therefore, in this example, the two-photon path bunching state can achieve twice the phase sensitivity of solution concentration sensing. The |11> state is selected as the projection measurement basis to measure the two-photon coincidence counting interference curve. The theoretical calculation value is as follows Figure 3 shown.

[0096] Example 3

[0097] This example provides a multi-parameter quantum sensing photon chip based on silicon-based materials, and uses it to perform air humidity sensing calculations; the specific difference from Example 2 is that the sensing calculation process is different. The humidity sensing calculation process of this example is as follows:

[0098] Phase difference between the two arms As the humidity h of the sensing unit changes, where λ is the wavelength. Represents the change in the effective refractive index n of the windowed waveguide (sensing arm) under unit humidity change. Under the parameters of the silicon waveguide (sensing arm) used in this example, RIUhf is approximately equal to 1.46×10 -4 % -1 Therefore, when the air humidity changes by 36%, the phase difference changes by 2π. After passing through the sensing unit, it is phase modulated (third phase shifter 19) and becomes After the 50:50 beam splitter (third beam splitter 20) interference, the output state becomes The two-photon path bunching state in this example (produced from the nonlinear unit) passes through the sensing unit and is phase modulated (by the third phase shifter 19) and becomes After the 50:50 beam splitter (third beam splitter 20) interference, the output state becomes

[0099] Therefore, this example uses the two-photon path bunching state (nonlinear unit) to achieve twice the phase sensitivity of air humidity sensing. The |11> state is selected as the projection measurement basis to measure the two-photon coincidence counting interference curve. The theoretical calculation value is as follows Figure 4 shown.

[0100] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A photon quantum chip for multi-parameter quantum sensing, characterized in that: The optical quantum chip for multi-parameter quantum sensing includes a substrate and an optical path arranged on the substrate; The optical path includes a classical laser processing unit, a nonlinear unit, a sensing unit and a quantum state output unit which are connected and arranged; The classical laser processing unit comprises a first beam splitter (7) connected in connection, a first waveguide (8) and a second waveguide (9) connected in parallel, and a second beam splitter (12); a first phase shifter (10) is arranged on the first waveguide (8); and a second phase shifter (11) is arranged on the second waveguide (9); The nonlinear unit is connected to the second beam splitter (12) and includes a first entangled photon pair generating waveguide (15) and a second entangled photon pair generating waveguide (16) which are arranged in parallel; The sensing unit comprises a reference arm (17) connected to the first entangled photon pair generating waveguide (15), and a sensing arm (18) connected to the second entangled photon pair generating waveguide (16); The quantum state output unit comprises a third beam splitter (20) connected to the reference arm (17) and the sensor arm (18).

2. The photon chip according to claim 1, characterized in that: The photonic quantum chip further comprises a covering layer and a buried layer; the buried layer is arranged on the surface of the substrate, the optical path is located above the buried layer, and the covering layer covers the optical path.

3. The optical quantum chip according to claim 2, characterized in that: The lengths of the sensing arm (18) and the reference arm (17) are not equal; and / or the lengths of the sensing arm (18) and the reference arm (17) are equal, and a covering layer in a local area of ​​the sensing arm (18) is etched.

4. The photon chip according to claim 1, characterized in that: The second beam splitter (12) and the first entangled photon pair generating waveguide (15) are connected via a third waveguide (13); and / or the second beam splitter (12) and the second entangled photon pair generating waveguide (16) are connected via a fourth waveguide (14).

5. The photon chip according to claim 1, characterized in that: A third phase shifter (19) is arranged on the reference arm (17).

6. The photon quantum chip according to any one of claims 1 to 5, characterized in that: The photon quantum chip comprises at least one input port, and the input port is connected to the first beam splitter (7); and / or the photon quantum chip further comprises at least two output ports; and the output ports are connected to the third beam splitter (20).

7. The photon chip according to any one of claims 1 to 5, characterized in that: The material of the nonlinear unit includes at least one of silicon, silicon nitride, aluminum gallium arsenide, silicon dioxide and lithium niobate.

8. A method for preparing a photon chip according to any one of claims 1 to 7, characterized in that: The preparation method includes arranging the optical path on the substrate.

9. The preparation method according to claim 8, characterized in that: The method for setting the optical path includes at least one of a photolithography method, an electron beam exposure method, a chemical exchange method, a mechanical cutting method and a chemical mechanical polishing method.

10. An application of the photon chip as claimed in any one of claims 1 to 7 in temperature, solution concentration, humidity, gas concentration and electric field testing.

Images