A high-sensitivity quantum sensing optical quantum chip, its setup method and application

Abstract

This invention discloses a high-sensitivity quantum sensing optical quantum chip, its setup method, and its applications, belonging to the field of sensor technology. The optical quantum chip provided by this invention includes a quantum light source module, a phase sensing interference module, and a tunable reflection module connected sequentially. The optical quantum chip provided by this invention has high sensitivity and a wide range of applications. This invention also provides the setup method and applications of the aforementioned optical quantum chip.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a high-sensitivity quantum sensing optical quantum chip, its setup method, and its applications. Background Technology

[0002] Interferometers using classical lasers suffer from the classical shot noise limit in terms of precision. According to the central limit theorem, repeated independent measurements N times (N much greater than 1) yield a normally distributed result with a measurement error of 1 / √N, known as the standard quantum limit. Quantum precision measurement, however, can overcome this limit by utilizing particle interactions. Entangled N particles can serve as a measurement resource, increasing the precision to 1 / N, a limit known as the Heisenberg limit. The resource states for quantum precision measurement are typically squeezed states or photon-entangled states (N0-N), where N photons are either all in path 1 or all in path 2. When performing phase measurements using N0-N states, the phase to be measured is incorporated into one path, and the two paths are then interferometric. Since all N photons pass through the phase to be measured, a suitable interferometer can ultimately reflect a sensitivity that is N times the phase. Methods for generating multiphoton entanglement typically include nonlinear processes to generate photon pairs and multiphoton interaction logic gates. Nonlinear processes include atomic cascade transitions, optical parametric down-conversion processes in second-order nonlinear crystals, and four-wave mixing processes in silicon-based or fiber-based systems. Multiphoton interaction logic gates include fusion operations and phase control gates. Numerous bulk optical experiments have been reported using these two multiphoton entanglement generation methods. Quantum photonic chips, fabricated on substrates such as silicon, silicon nitride, and lithium niobate, are an emerging technology. Their emergence overcomes the problem of large space requirements in bulk optics, enabling the integration of thousands of optical components on millimeter-scale chips. Gratings guide the input and output of light, and waveguides guide the propagation of light; the phase generated by photons traveling through the waveguide exhibits high stability. Compared with other types of chips, the manufacturing process of silicon-based electronic chips is relatively complete, and has been scaled up and industrialized. Silicon-based optical chips have higher process precision and are easier to realize than chips made of other materials. In the silicon-based four-wave mixing process, two pump photons annihilate to produce a pair of converted photons that satisfy the conservation of energy and momentum, which are called signal photons and idle photons, respectively. In the degenerate four-wave mixing process, two pump photons of different frequencies annihilate to produce a pair of photons of the same frequency.

[0003] However, current experiments have only achieved quantum precision measurement with four photons. It is difficult to extend traditional methods to more photons and higher precision measurement. There is still a lack of a high sensing factor, configurable and easy-to-implement solution. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a high-sensitivity quantum sensing optical quantum chip, which can effectively improve the stability, resolution, and precision of detection; moreover, the optical quantum chip provided by this invention has high integration and can realize multi-parameter sensing.

[0005] The present invention also provides a method for setting up the above-mentioned optical quantum chip.

[0006] This invention also provides applications of the aforementioned optical quantum chip.

[0007] According to an embodiment of a first aspect of the present invention, a high-sensitivity quantum sensing optical quantum chip is provided, the optical quantum chip comprising a quantum light source module, a phase sensing interference module and an adjustable reflection module connected in sequence.

[0008] The control method according to embodiments of the present invention has at least the following beneficial effects:

[0009] The photonic quantum chip provided by this invention is equipped with an adjustable reflection module, which enables photons to pass through the phase sensing interference module back and forth, thereby achieving a higher phase accuracy (compared to not having an adjustable reflection module).

[0010] The photonic quantum chip provided by this invention utilizes integrated optical technology; it integrates three modules, improving the scalability, integration, and stability of multiphoton precision measurement experiments; it also features high integration, high spatial resolution, and multi-parameter sensing.

[0011] According to some embodiments of the present invention, the quantum light source module includes:

[0012] First Mach-Zehnder interferometer;

[0013] A phase shifter, which is connected to one optical path exit of the first Mach-Zehnder interferometer;

[0014] Waveguide, the waveguide and the phase shifter are connected;

[0015] A second Mach-Zehnder interferometer and a third Mach-Zehnder interferometer are configured in parallel and connected to the waveguide.

[0016] The first Mach-Zehnder interferometer acts as a beam splitter, dividing the classical pump light into two paths of equal amplitude. The phase shifter and waveguide function as collinear nonlinear light sources, undergoing a degenerate spontaneous four-wave mixing process or a spontaneous parametric down-conversion process. The two paths generated by the beam splitter produce photon pairs in this step, achieving a superimposed photon source. The second and third Mach-Zehnder interferometers function as pump filters, in which the pump light is filtered out, and the converted photons enter the phase sensing interferometer module, achieving separation of the pump light and the converted photons. When the three are combined, a four-wave mixing or spontaneous parametric down-conversion quantum light source can be obtained, enabling the preparation of 2, 4, or 6 photon path superposition states. Even when the tunable reflection module is turned off, the photonic quantum chip provided by this invention can still measure states with 6 times the phase accuracy. When the tunable reflection module is turned on, the phase sensing accuracy (sensitivity) of the photonic quantum chip provided by this invention can reach up to 12 times, and can simultaneously achieve 4 times or 8 times the sensing sensitivity.

[0017] According to some embodiments of the present invention, the quantum light source module further includes an input optical fiber and a grating; wherein the classical laser, after passing through the input optical fiber and the grating in sequence, is split and processed by the first Mach-Zehnder interferometer.

[0018] According to some embodiments of the present invention, the quantum light source module further includes a first intermediate optical path connected in parallel with the phase shifter and connected to another optical path exit of the first Mach-Zehnder interferometer. It is understood that the first intermediate optical path is connected to the waveguide. That is, of the two beams split from the first Mach-Zehnder interferometer, one enters the phase shifter; the other enters the first intermediate optical path.

[0019] According to some embodiments of the present invention, the quantum light source module further includes a fourth Mach-Zehnder interferometer and a fifth Mach-Zehnder interferometer disposed in parallel between the first Mach-Zehnder interferometer and the waveguide.

[0020] The fourth Mach-Zehnder interferometer is located between the phase shifter and the waveguide. Specifically, one optical path inlet of the fourth Mach-Zehnder interferometer is connected to the phase shifter, and one optical path outlet is connected to the waveguide.

[0021] The fifth Mach-Zehnder interferometer is positioned between the first intermediate optical path and the waveguide. Specifically, one optical path inlet of the fifth Mach-Zehnder interferometer is connected to the first intermediate optical path, and one optical path outlet is connected to the waveguide.

[0022] According to some embodiments of the present invention, the fourth Mach-Zehnder interferometer and the fifth Mach-Zehnder interferometer are unequal-arm Mach-Zehnder interferometers.

[0023] According to some embodiments of the present invention, the waveguide is at least one of a straight helical waveguide or a micro-ring resonator. The straight helical waveguide refers to a straight waveguide wound into a helical shape, its function being to generate a multiphoton source through a nonlinear process.

[0024] According to some embodiments of the present invention, the second and third Mach-Zehnder interferometers are unequal-arm Mach-Zehnder interferometers.

[0025] According to some embodiments of the present invention, the optical quantum chip further includes a first output optical fiber connected to the fourth Mach-Zehnder interferometer.

[0026] According to some embodiments of the present invention, the quantum light source module further includes a first output waveguide connecting the fourth Mach-Zehnder interferometer and the first output optical fiber. It is understood that a filter is provided between the first output waveguide and the first output optical fiber.

[0027] According to some embodiments of the present invention, the optical quantum chip further includes a second output optical fiber connected to the fifth Mach-Zehnder interferometer.

[0028] According to some embodiments of the present invention, the quantum light source module further includes a second output waveguide connecting the fifth Mach-Zehnder interferometer and the second output optical fiber. It is understood that a filter is provided between the second output optical fiber and the second output waveguide.

[0029] According to some embodiments of the present invention, the phase sensing interferometer module includes a first multimode interferometer, a phase shifter under test, a second multimode interferometer, and a bias phase shifter, which are sequentially connected to the quantum light source module.

[0030] According to some embodiments of the present invention, the phase sensing interferometer module further includes a second intermediate optical path connected to the first multimode interferometer and in parallel with the phase shifter under test. That is, in practical applications, the two optical paths formed by beam splitting via the first multimode interferometer pass through the phase shifter under test and the second intermediate optical path, respectively, before entering the second multimode interferometer.

[0031] According to some embodiments of the present invention, the first multimode interferometer and the second multimode interferometer are 50:50 interferometers, meaning that the two beams of light separated are equal.

[0032] According to some embodiments of the present invention, the phase sensing interferometer module further includes a third intermediate optical path connected in parallel with the bias phase shifter. That is, in practical applications, the two beams generated by the second multimode interferometer beam splitting are transmitted through the bias phase shifter and the third intermediate optical path, respectively.

[0033] According to some embodiments of the present invention, the adjustable reflection module includes a first tail-connected Mach-Zehnder interferometer and a second tail-connected Mach-Zehnder interferometer connected to the phase sensing interferometer module; a first photon outlet connected to the first tail-connected Mach-Zehnder interferometer and a second photon outlet connected to the second tail-connected Mach-Zehnder interferometer. The two outlets of each of the first and second tail-connected Mach-Zehnder interferometers are connected, thereby forming a light loop and realizing photon reflection.

[0034] According to some embodiments of the present invention, the first photon outlet is connected to a first tail-connected Mach-Zehnder interferometer, and the second photon outlet is connected to a second tail-connected Mach-Zehnder interferometer. In actual production, if the first and second tail-connected Mach-Zehnder interferometers are turned off, photons are output from the first and / or second photon outlets. Detecting the |1,1> term of the output state can achieve 2x phase induction; detecting the |1,3> or |3,1> term of the output state can achieve 4x phase induction; detecting the |3,3> term of the output state can obtain a 6x phase induction curve.

[0035] If the first and second Mach-Zehnder interferometers are operational, photons return along their original path to the phase-sensing interferometer module, and finally exit from the fourth and fifth Mach-Zehnder interferometers of the quantum light source module, via the first / second output waveguide, and ultimately from the first and second output optical fibers. Detecting the |1,1> term of the output state (|1,1> indicates that the first and second output optical fibers both detect one photon, representing a coincidence count between two photons) can achieve 4 times phase sensing. Detecting the output state's |1,3> or |3,1> term (|3,1> indicates that the first output fiber detects 3 photons and the second output fiber detects 1 photon, which is a four-photon coincidence count; similarly, |1,3> indicates that the first output fiber detects 1 photon and the second output fiber detects 3 photons, which is also a four-photon coincidence count) can achieve 8 times phase sensing; detecting the output state's |3,3> term (|3,3> indicates that the first output fiber detects 3 photons and the second output fiber detects 3 photons, which is a six-photon coincidence count) can obtain a phase sensing curve of up to 12 times.

[0036] According to some embodiments of the present invention, the material of the photonic quantum chip includes at least one of third-order nonlinear materials and second-order nonlinear materials.

[0037] According to some embodiments of the present invention, the material of the photonic quantum chip includes at least one selected from silicon, silicon nitride, gallium arsenide, and lithium niobate. Specifically, lithium niobate is the second-order nonlinear material, and the other materials are the third-order nonlinear materials.

[0038] Unless otherwise specified, the interferometers used in this invention are all 2×2 interferometers, that is, they have two optical path inlets and two optical path outlets.

[0039] Unless otherwise specified, the interferometer used in this invention includes a phase adjustment module.

[0040] Unless otherwise specified, in this invention, the phase shift adjustment method in the interferometer's phase adjustment module and the phase shifter includes at least one of electro-optic modulation, thermo-optic modulation, and optical-optic modulation. The principle is to fabricate electrodes on the interferometer or phase shifter, and then apply an electric field to change the refractive index of that section of the optical path (also called the waveguide), thereby modulating the phase of the photons. In actual production, a suitable phase shift adjustment method can be selected according to the object being measured (temperature, humidity, etc.). As long as the phase shift adjustment method matches the object being measured, the selected phase shift adjustment method has almost no impact on the test results.

[0041] According to an embodiment of a second aspect of the present invention, a method for setting up the aforementioned optical quantum chip is provided, the method comprising waveguide processing of a blank.

[0042] Since the setting method adopts all the technical solutions of the optical quantum chip in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0043] According to some embodiments of the present invention, the waveguide fabrication method is at least one of chemical exchange, mechanical cutting, chemical mechanical polishing, ion beam etching, and laser direct writing. These waveguide fabrication methods are relatively mature in industry. In actual production, a suitable waveguide fabrication method can be selected based on experience, according to the specific structure and material of the quantum chip; and the waveguide fabrication method has no significant impact on the performance of the resulting quantum chip.

[0044] According to an embodiment of a third aspect of the present invention, an application of the aforementioned quantum chip in the detection of temperature, gas concentration, humidity, electric field, and pressure is provided.

[0045] Since the application adopts all the technical solutions of the optical quantum chip in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0046] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0047] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0048] Figure 1 This is a schematic diagram of the optical quantum chip provided in Embodiment 1 of the present invention;

[0049] Figure 2 These are the single-photon measurement results under ideal conditions of turning the adjustable reflection module off and on in Example 2;

[0050] Figure 3 These are the two-photon measurement results under ideal conditions of turning the adjustable reflection module off and on in Example 3;

[0051] Figure 4 These are the four-photon measurement results under ideal conditions of turning the adjustable reflection module off and on in Example 4;

[0052] Figure 5 These are the six-photon measurement results under ideal conditions of turning the adjustable reflection module off and on in Example 5;

[0053] Figure label:

[0054] Quantum light source module I, phase sensing interference module II, adjustable reflection module III;

[0055] Classical laser 1. Input fiber 2. Grating 3. First Mach-Zehnder interferometer 4. Phase shifter 5. Waveguide 6. Second Mach-Zehnder interferometer 7. Third Mach-Zehnder interferometer 8. First multimode interferometer 9. Phase shifter under test 10. Second multimode interferometer 11. Bias phase shifter 12. First tail-connected Mach-Zehnder interferometer 13. Fourth Mach-Zehnder interferometer 14. Fifth Mach-Zehnder interferometer 15. First output fiber 16. Second output fiber 17. First photon outlet 18. Second photon outlet 19. Second tail-connected Mach-Zehnder interferometer 20. Detailed Implementation

[0056] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0057] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0058] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] Example 1

[0060] refer to Figure 1 This example uses non-degenerate spontaneous four-wave mixing in silicon-based materials to demonstrate a photonic quantum chip capable of sensing up to 12 times the phase, and provides an application for phase adjustment. Specifically:

[0061] The optical quantum chip provided in this example includes a quantum light source module I, a phase sensing interference module II, and an adjustable reflection module III, which are connected in sequence.

[0062] Quantum light source module I includes:

[0063] Connect the input fiber 2, grating 3, and first Mach-Zehnder interferometer 4;

[0064] The phase shifter 5 and the first intermediate optical path are connected in parallel and are connected to the first Mach-Zehnder interferometer 4;

[0065] The fourth Mach-Zehnder interferometer 14 and the fifth Mach-Zehnder interferometer 15 are configured in parallel; specifically, the fourth Mach-Zehnder interferometer 14 is connected to the phase shifter 5; and the fifth Mach-Zehnder interferometer 15 is connected to the first intermediate optical path.

[0066] Waveguide 6 has two entrances that are connected to the fourth Mach-Zehnder interferometer 14 and the fifth Mach-Zehnder interferometer 15, respectively; waveguide 6 is a straight waveguide wound in a spiral shape.

[0067] The second Mach-Zehnder interferometer 7 and the third Mach-Zehnder interferometer 8 are set in parallel and connected to the two outlets of waveguide 6;

[0068] In this example, the quantum light source module I also includes a first output waveguide and a first output fiber 16 that are sequentially connected to the fourth Mach-Zehnder interferometer 14; and a second output waveguide and a second output fiber 17 that are connected to the fifth Mach-Zehnder interferometer 15.

[0069] In this example, the second Mach-Zehnder interferometer 7, the third Mach-Zehnder interferometer 8, the fourth Mach-Zehnder interferometer 14, and the fifth Mach-Zehnder interferometer 15 are Mach-Zehnder interferometers with unequal arms.

[0070] Phase sensing interferometry module II includes:

[0071] The first multimode interferometer 9, the phase shifter under test 10, the second intermediate optical path, the second multimode interferometer 11, the bias phase shifter 12, and the third intermediate optical path are sequentially connected to the quantum light source module I.

[0072] in,

[0073] The first multimode interferometer 9 and the second multimode interferometer 11 are 50:50 interferometers.

[0074] Adjustable reflection module III includes:

[0075] A Mach-Zehnder interferometer 13 is connected to the first tail end of the bias phase shifter 12, and a first photon outlet 18 is connected thereto.

[0076] The second tail end is connected to the third intermediate optical path, which is connected to the Mach-Zehnder interferometer 20 and the second photon outlet 19 connected to it;

[0077] In this example, the Mach-Zehnder interferometer 13 and the Mach-Zehnder interferometer 20 connected at the tail end are specifically 2×2 Mach-Zehnder interferometers with their two output ends connected.

[0078] In this example, the photonic quantum chip is made of silicon, and the other interferometers are all 2×2 interferometers. The phase shift adjustment method used in the interferometers and phase shifters is at least one of electro-optic modulation, thermo-optic modulation, and optical-optic modulation.

[0079] In this example, the method for setting up the quantum chip is to perform waveguide processing on the blank. The waveguide processing method is at least one of chemical exchange method, mechanical cutting method, chemical mechanical polishing method, ion beam etching and laser direct writing.

[0080] In actual use,

[0081] Classical laser 1 is coupled into grating 3 via input fiber 2, and then split into two equal paths by a first Mach-Zehnder interferometer 4 (adjustable). One path has a phase shifter 5 to adjust the relative phase of the two paths; the other path passes through a first intermediate optical path. Subsequently, the two paths pass through a fourth Mach-Zehnder interferometer 14 and a fifth Mach-Zehnder interferometer 15, respectively, and then enter a waveguide 6. The two beams generated by waveguide 6 pass through a parallel second Mach-Zehnder interferometer 7 and a third Mach-Zehnder interferometer 8, respectively. During this process, the pump light is filtered out, and the converted photons then enter the phase-sensing interferometer module II, achieving separation of the pump light and the converted photons. In the phase-sensing interferometer module II, the converted photons first pass through a first multimode interferometer 9, then the upper path passes through the phase shifter 10 under test, and the lower path passes through a second intermediate optical path. Afterward, they are converged and split in the second multimode interferometer 11, the upper path passes through a bias phase shifter 12, and the lower path passes through a third intermediate optical path. The two converted photons are respectively fed into the first tail-connected Mach-Zehnder interferometer 13 and the second tail-connected Mach-Zehnder interferometer 20 in the adjustable reflection module III.

[0082] When the phases of the first Mach-Zehnder interferometer 13 and the second Mach-Zehnder interferometer 20 connected to the first tail end are both tuned to Pi / 2 (operating state), the converted photons can return to the phase sensing interferometer module II along the original path. Finally, they are transferred from the fourth Mach-Zehnder interferometer 14 and the fifth Mach-Zehnder interferometer 15 in the quantum light source module I to the two output waveguides, and finally pass through the first and second output waveguides, and are output from the first output fiber 16 and the second output fiber 17 for detection, respectively. Detecting the |1,1> term of the output state can achieve 4 times phase sensing; detecting the |1,3> or |3,1> term of the output state can achieve 8 times phase sensing; detecting the |3,3> term of the output state can obtain a maximum phase sensing curve of 12 times.

[0083] If the Mach-Zehnder interferometer 13 connected to the first end and the Mach-Zehnder interferometer 20 connected to the second end are not working (both phases are adjusted to 0 or Pi), then photons are output from the first photon outlet 18 and the second photon outlet 19. Detecting the |1,1> term of the output state can achieve 2 times phase induction; detecting the |1,3> or |3,1> term of the output state can achieve 4 times phase induction; and detecting the |3,3> term of the output state can obtain a 6 times phase induction curve.

[0084] Example 2

[0085] This example provides a specific application of the optical quantum chip obtained in Embodiment 1:

[0086] The wavelength of the classical laser 1 (pump light) is 1550.92 nm. When the phase shifter 5 is set to Pi, and the first Mach-Zehnder interferometer 13 and the second Mach-Zehnder interferometer 20 connected to the second end are not working, measuring the light field intensity at the first photon exit 18 or the second photon exit 19 yields an interference curve with single-fold phase induction. When the phase shifter 5 and the bias phase shifter 12 are set to Pi, and the first Mach-Zehnder interferometer 13 and the second Mach-Zehnder interferometer 20 are working, measuring the light field intensity at the first output fiber 16 or the second output fiber 17 yields an interference curve with double-fold phase induction. In this example, the specific results regarding whether the first Mach-Zehnder interferometer 13 and the second Mach-Zehnder interferometer 20 are on are as follows: Figure 2 As shown.

[0087] Example 3

[0088] This example provides a specific application of the optical quantum chip obtained in Embodiment 1:

[0089] The wavelength of the classical laser 1 (pump light) is 1550.92 nm, and the signal light and idle light in the photon pair are 1554.94 nm and 1547.72 nm, respectively. When phase shifter 5 is set to Pi, and the first Mach-Zehnder interferometer 13 and the second Mach-Zehnder interferometer 20 connected to the first end are not working, measuring the photons at the first photon exit 18 and the second photon exit 19, and probing the |1,1> term of the output state, an interference curve with 2 times phase induction can be obtained. When phase shifter 5 and bias phase shifter 12 are set to Pi, and the first Mach-Zehnder interferometer 13 and the second Mach-Zehnder interferometer 20 connected to the first end are working, measuring the photons at the first output fiber 16 and the second output fiber 17, and probing the |1,1> term of the output state, an interference curve with 4 times phase induction can be obtained. In this example, the specific results of whether the first Mach-Zehnder interferometer 13 and the second Mach-Zehnder interferometer 20 connected to the first end are on are as follows: Figure 3 As shown.

[0090] The difference between this embodiment and Embodiment 2 is that this embodiment measures two-photon coincidence counts, while Embodiment 2 measures single-photon counts.

[0091] Example 4

[0092] This example provides a specific application of the optical quantum chip obtained in Embodiment 1:

[0093] The wavelength of the classical laser 1 (pump light) is 1550.92 nm, and the wavelengths of the signal light and idler light in the photon pair are 1554.94 nm and 1547.72 nm, respectively. When phase shifter 5 is set to Pi, and the first end-connected Mach-Zehnder interferometer 13 and the second end-connected Mach-Zehnder interferometer 20 are not working, measuring the photons at the first photon exit 18 and the second photon exit 19, and probing the |3,1> or |1,3> term of the output state, an interference curve with 4 times phase induction can be obtained. When phase shifter 5 and bias phase shifter 12 are set to Pi, and the first end-connected Mach-Zehnder interferometer 13 and the second end-connected Mach-Zehnder interferometer 20 are working, measuring the photons at the first output fiber 16 and the second output fiber 17, and probing the |3,1> or |1,3> term of the output state, an interference curve with 8 times phase induction can be obtained. In this example, the specific results regarding whether the Mach-Zehnder interferometer 13 connected at the first end and the Mach-Zehnder interferometer 20 connected at the second end are activated are as follows: Figure 4 As shown.

[0094] The difference between this embodiment and Embodiment 2 is that this embodiment measures the four-photon coincidence count, while Embodiment 2 measures the single-photon count.

[0095] Example 5

[0096] This example provides a specific application of the optical quantum chip obtained in Embodiment 1:

[0097] The wavelength of the classical laser 1 (pump light) is 1550.92 nm, and the wavelengths of the signal light and idler light in the photon pair are 1554.94 nm and 1547.72 nm, respectively. When phase shifter 5 is set to ArcCos(-3 / 5), and the first end-connected Mach-Zehnder interferometer 13 and the second end-connected Mach-Zehnder interferometer 20 are not working, measuring the photons at the first photon exit 18 and the second photon exit 19, and probing the |3,3> term of the output state, an interference curve with 6 times phase induction can be obtained. When phase shifter 5 is set to ArcCos(-3 / 5) and bias phase shifter 12 is set to Pi, and the first end-connected Mach-Zehnder interferometer 13 and the second end-connected Mach-Zehnder interferometer 20 are working, measuring the photons at the first output fiber 16 and the second output fiber 17, and probing the |3,3> term of the output state, an interference curve with 12 times phase induction can be obtained. In this example, the specific results regarding whether the Mach-Zehnder interferometer 13 connected at the first end and the Mach-Zehnder interferometer 20 connected at the second end are activated are as follows: Figure 5 As shown.

[0098] The difference between this embodiment and Embodiment 2 is that this embodiment measures six-photon coincidence counts, while Embodiment 2 measures single-photon counts.

[0099] As can be seen from the above description, the photonic quantum chip provided by this invention, through reasonable structural design, can obtain an interference curve with up to 12 times the phase sensing, and has high resolution, accuracy and stability. In addition, the photonic quantum chip provided by this invention has the effects of high integration and high spatial resolution. Finally, this invention can select a suitable phase adjustment method to realize the sensing and detection of multiple parameters such as temperature, gas concentration, humidity, electric field, and pressure.

[0100] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A high-sensitivity quantum sensing optical quantum chip, characterized by, The light quantum chip comprises a quantum light source module (I), a phase sensing interference module (II) and an adjustable reflection module (III) connected in sequence. The quantum light source module (I) comprises: a first Mach-Zehnder interferometer (4); a phase shifter (5) connected with one light path outlet of the first Mach-Zehnder interferometer (4); a waveguide (6) connected with the phase shifter (5); a second Mach-Zehnder interferometer (7) and a third Mach-Zehnder interferometer (8) connected in parallel and with the waveguide (6); The phase sensing interference module (II) comprises a first multimode interferometer (9), a to-be-measured phase shifter (10), a second multimode interferometer (11) and a bias phase shifter (12) connected in sequence with the quantum light source module (I). The adjustable reflection module (III) comprises a first tail-end connected Mach-Zehnder interferometer (13) and a second tail-end connected Mach-Zehnder interferometer (20) connected with the phase sensing interference module (II); and a first photon outlet (18) connected with the first tail-end connected Mach-Zehnder interferometer (13) and a second photon outlet (19) connected with the second tail-end connected Mach-Zehnder interferometer (20).

2. The optical quantum chip of claim 1, wherein, The quantum light source module (I) further comprises a fourth Mach-Zehnder interferometer (14) and a fifth Mach-Zehnder interferometer (15) connected in parallel between the first Mach-Zehnder interferometer (4) and the waveguide (6).

3. The optical quantum chip of claim 2, wherein, The light quantum chip further comprises a first output optical fiber (16) connected with the fourth Mach-Zehnder interferometer (14).

4. The photonic quantum chip of claim 2, wherein, The light quantum chip further comprises a second output optical fiber (17) connected with the fifth Mach-Zehnder interferometer (15).

5. The photonic quantum chip of claim 1, wherein, The material of the light quantum chip comprises at least one of a third-order nonlinear material and a second-order nonlinear material.

6. The photonic quantum chip of claim 1, wherein, The material of the light quantum chip comprises at least one of silicon, silicon nitride, gallium arsenide and lithium niobate.

7. A method of arranging optical quantum chips as claimed in any one of the claims 1-6, characterized in that The setting method comprises waveguide processing on a blank.

8. Application of the light quantum chip according to any one of claims 1-6 in temperature, gas concentration, humidity, electric field and pressure detection.

Images