CN109196397B - For generating the device and system, fixed single-photon source method of single photon - Google Patents

Abstract

A device and system for generating single photons, and a method for fixing a single photon source, the device for generating single photons includes a waveguide; a resonant cavity located above the waveguide; a thermosensitive polymer located above the resonant cavity above the waveguide; wherein the thermally sensitive polymer is hydrophilic at a temperature less than a threshold value and hydrophobic at a temperature not lower than a threshold value. The device for generating single photons has a simple structure and is easy to manufacture, which simplifies the manufacturing process of the device for generating single photons.

Description

Device and system for generating single photon, fixed single photon source method

technical field

The invention relates to the technical field of quantum information equipment, in particular to a device and system for generating single photons, and a method for fixing a single photon source.

Background technique

Quantum information science is the product of the combination of quantum mechanics and information science and technology, including quantum cryptography, quantum communication, quantum computing, quantum measurement, etc. In recent years, important breakthroughs have been made in theory and experiment. Whether it is quantum communication or quantum computing, a stable, high-rate single photon source is a key device that must be solved. A single photon source is a light source that emits only one photon at a time.

In the prior art, in order to generate single photons, the luminescent materials indium arsenide (InAs) and aluminum indium arsenide (AlGaAs) quantum dots are usually coupled into nanowires with similar lattice structures during growth. After the luminescent material is excited, it generates spontaneous emission due to photoluminescence, and releases a single photon flow equal to the forbidden band energy. Since these photons are trapped in nanowires similar to optical waveguides, they have specific light-emitting directions and light-emitting field distributions.

In the above solutions, growing InAs and AlGaAs quantum dots into nanowires requires a relatively high level of processing and a relatively complex manufacturing process.

Contents of the invention

Embodiments of the present invention provide a device and system for generating single photons, and a method for fixing a single photon source, which are used to simplify the manufacturing process of the device for generating single photons and generate single photons through a simple method.

In a first aspect, an embodiment of the present invention provides a device for generating single photons, including: a waveguide; a resonant cavity located above the waveguide; a thermosensitive polymer located above the waveguide provided with the resonant cavity; Wherein, the thermosensitive polymer is hydrophilic under the condition of less than the temperature threshold, and is hydrophobic under the condition of not less than the temperature threshold. It can be seen that the device for generating single photons has a simple structure and is easy to manufacture, which simplifies the manufacturing process of the device for generating single photons.

Optionally, the resonant cavity is a surface plasmon resonant cavity. In this way, the light intensity of the single photons located in the resonant cavity can be further increased. Optionally, the resonant cavity is composed of two metal pieces. In this way, the light intensity of the single photons located in the resonant cavity can be further increased. Optionally, the resonant cavity is formed by any of the following forms: it is formed by two vertex corners respectively located on two triangular metal parts with a predetermined distance apart; it is formed by a double metal nanowire with a predetermined distance apart; it is formed by a double metal nanowire The balls are formed at a preset distance apart. In this way, on the one hand, the single photon in the resonant cavity can be better fixed, and on the other hand, the light intensity of the single photon in the resonant cavity can also be increased.

Optionally, the device for generating single photons further includes an antenna. The antenna is located above the waveguide and below the heat-sensitive polymer; wherein the resonant cavity is located at the feeding component of the antenna. In this way, the single photons generated at the resonant cavity of the device for generating single photons can propagate along a specific direction at the feeding component of the antenna, thereby well controlling the direction of the generated single photons. Further, placing the resonant cavity at the feeding component of the antenna can enhance the light intensity of the photons generated at the resonant cavity. In the third aspect, since the antenna is placed above the waveguide, the antenna can generate an obliquely downward light field, which enters the waveguide, so that the single photon generated at the resonant cavity can be better coupled into the waveguide. Optionally, the antenna is a Yagi antenna. In this way, the propagation of single photons in a specific direction can be better controlled.

In the second aspect, the embodiment of the present invention provides a method for fixing a single photon source in any device for generating single photons in the embodiment of the present invention, including: at the resonant cavity on the device for generating single photons Irradiating laser light; flowing into a liquid carrying a single-photon source on the surface of the thermosensitive polymer; wherein, the ligand of the single-photon source in the liquid carrying a single-photon source is hydrophobic; wherein, the laser is used for : increasing the temperature in the resonant cavity, changing the thermosensitive polymer from hydrophilic to hydrophobic, and attracting the liquid carrying the single photon source to stay in the resonant cavity. It can be seen that the device for generating single photons has a simple structure and is easy to manufacture, which simplifies the manufacturing process of the device for generating single photons.

Optionally, the single-photon source in the liquid carrying the single-photon source is a colloidal quantum dot or a dye molecule. In this way, on the one hand, the single photon source used in the embodiment of the present invention does not require harsh environmental requirements, such as requiring extremely low ambient temperature, etc., thereby simplifying the production process; on the other hand, the liquid carrying the single photon source can be made The upper surface of the device for generating single photons provided in the embodiment of the present invention flows, thereby successfully implementing the solution provided in the embodiment of the present invention.

Optionally, the difference between the local oscillation frequency of the resonant cavity and the local oscillation frequency of the single photon source is less than the resonance frequency threshold; the local oscillation frequency of the antenna further included in the device for generating single photons The difference from the local oscillator frequency of the single photon source is less than the resonance frequency threshold. In this way, the local oscillation frequency of the resonant cavity is relatively close to that of the single photon source, so resonance can occur under the action of laser light, thereby enhancing the light intensity of the single photon. Moreover, the local oscillator frequency of the antenna is relatively close to that of the single photon source, so resonance can occur under the action of the laser, thereby enhancing the light intensity of the single photon.

In a third aspect, an embodiment of the present invention provides a single photon generation system, including any one of the devices for generating single photons provided in the embodiments of the present invention, a laser and a liquid inflow device, wherein: the laser is used for Laser light is irradiated at the resonant cavity on the device for generating single photons; the liquid inflow device is used to flow into the liquid carrying a single photon source on the surface of the thermosensitive polymer; wherein, the carrying single photon source The ligand of the single-photon source in the liquid is hydrophobic; wherein, the laser is used to: increase the temperature in the resonant cavity, and convert the thermosensitive polymer from hydrophilic to hydrophobic , and attract the liquid carrying the single photon source to stay in the resonant cavity, and make the liquid carrying the single photon source staying in the resonant cavity emit single photons under the irradiation of the laser, the Single photons are coupled into the waveguide for internal transport.

In an embodiment of the present invention, the device for generating single photons includes a waveguide; a resonant cavity located above the waveguide; a thermosensitive polymer located above the waveguide provided with the resonant cavity; wherein the thermosensitive polymer Substances are hydrophilic when the temperature is less than the threshold, and hydrophobic when the temperature is not less than the threshold. It can be seen that the device for generating single photons has a simple structure and is easy to manufacture, which simplifies the manufacturing process of the device for generating single photons.

Further, when generating single photons based on the device for generating single photons, only the resonant cavity on the device for generating single photon sources is used to irradiate laser light; Liquid will do. Because the ligand of the single-photon source in the liquid carrying the single-photon source is hydrophobic. Therefore, irradiating the laser at the resonant cavity can increase the temperature in the resonant cavity, convert the thermosensitive polymer from hydrophilic to hydrophobic, and attract the liquid carrying the single photon source to stay in the The liquid carrying the single-photon source staying in the resonant cavity emits a single photon under the irradiation of the laser, and the single photon is coupled to the waveguide for transmission. It can be seen that, in the embodiment of the present invention, a single photon is generated through a simple method, and the coupling of the single photon to the waveguide is realized.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings that need to be used in the description of the embodiments.

Fig. 1 is a schematic structural diagram of a device for generating single photons provided by an embodiment of the present invention;

2 is a schematic diagram of the method steps for preparing a device for generating single photons provided by an embodiment of the present invention;

3 is a schematic diagram of the method steps for preparing a device for generating single photons provided by an embodiment of the present invention;

4 is a schematic diagram of the method steps for preparing a device for generating single photons provided by an embodiment of the present invention;

5 is a schematic diagram of the method steps for preparing a device for generating single photons provided by an embodiment of the present invention;

6 is a schematic diagram of the method steps for preparing a device for generating single photons provided by an embodiment of the present invention;

Fig. 7 is a schematic diagram of direction A in Fig. 6 provided by an embodiment of the present invention;

FIG. 8 is a method for fixing a single photon source in a device for generating single photons provided by an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a single photon generation system provided by an embodiment of the present invention;

Fig. 10 is a schematic diagram of direction A in Fig. 9 provided by an embodiment of the present invention;

Fig. 11 is a schematic diagram of the light intensity of a single photon in a resonant cavity and the light intensity in free space in an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and beneficial effects of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

In specific implementation, in many fields, a stable, high-rate single-photon source is a key device that must be solved. Specifically, in the field of quantum communication, the generated single photons can be used as qubits and transmitted in self-used space or optical fibers, where the quality of the single photon light source has a decisive impact on key yield and photon coherence. In the field of quantum computing, a large number of parallel operations can be performed using the linear action of single or entangled photons. Among them, whether a single photon light source can generate "determined (on-demand, that is, non-probability generated)" photons is the key to the success of quantum computing. one of the prerequisites. In terms of metrology, single photons can be used for super-diffraction-limited imaging of biological samples, where the brightness and monochromaticity of a single photon also play a decisive role in imaging quality. In terms of basic experiments, the verification of Bell's inequality in quantum mechanics, and the search for gravitational waves, single photons also play a huge role.

Based on the above polling, an embodiment of the present invention provides a device and system for generating single photons, and a method for fixing a single photon source, which are used to simplify the manufacturing process of devices for generating single photons, and generate single photon.

FIG. 1 exemplarily shows a schematic structural diagram of a device for generating single photons provided by an embodiment of the present invention. As shown in FIG. 1 , the device for generating single photons includes: a waveguide 102; a resonant cavity 103; Thermally Sensitive Polymers 105.

Wherein, the resonant cavity 103 is located above the waveguide; the thermosensitive polymer 105 is located above the waveguide 102 provided with the resonant cavity 103; wherein, the thermosensitive polymer 105 is hydrophilic under the condition of less than the temperature threshold It is hydrophobic under the condition of not less than the temperature threshold. The temperature threshold is a temperature value, which can be determined according to a specific operating environment.

Optionally, the resonant cavity is a surface plasmon resonant cavity. Optionally, the resonant cavity is composed of two metal pieces. Optionally, the resonant cavity is composed of two nano-metal parts. In this way, the light intensity of the single photons located in the resonant cavity can be further increased.

Optionally, the resonant cavity is formed by any of the following forms: it is formed by two vertex corners respectively located on two triangular metal parts with a predetermined distance apart; it is formed by a double metal nanowire with a predetermined distance apart; it is formed by a double metal nanowire The balls are formed at a preset distance apart. Specifically, the resonant cavity can be composed of two parts with a preset distance between the two parts, for example, the two sharp corners of two triangles are separated by a preset distance, at this time, the two parts can form a resonant cavity, For details, refer to the resonant cavity 103 shown in FIG. 7 . Another example is formed by the tops of two bimetallic nanowires separated by a predetermined distance; another example is formed by bimetallic nanospheres separated by a predetermined distance. In this way, on the one hand, the single photon in the resonant cavity can be better fixed, and on the other hand, the light intensity of the single photon in the resonant cavity can also be increased.

In the embodiment of the present invention, under the action of the heat-sensitive polymer, single photons are generated at the resonant cavity and guided into the waveguide. It can be seen that the device for generating single photons has a simple structure and is easy to manufacture, which simplifies the manufacturing process of the device for generating single photons.

Optionally, in order to better control the direction of single photons, the device for generating single photons further includes: an antenna located above the waveguide and below the thermosensitive polymer; wherein the resonant cavity is located on the A resonant cavity is used at the feed component of the antenna, that is, the resonant cavity forms the feed component of the antenna. In this way, the single photons generated at the resonant cavity of the device for generating single photons can propagate along a specific direction at the feeding component of the antenna, thereby well controlling the direction of the generated single photons. Furthermore, the use of a resonant cavity structure at the feeding component of the antenna can enhance the light intensity of the single photon generated at the resonant cavity. In the third aspect, since the antenna is placed above the waveguide, the antenna can generate an obliquely downward light field, which enters the waveguide, so that the single photon generated at the resonant cavity can be better coupled into the waveguide.

Optionally, there may be various types of antennas, as long as the single photon can be controlled to propagate in a specific direction. Preferably, the antenna is a Yagi antenna.

Based on the above description, an embodiment of the present invention provides a method for preparing the above-mentioned device for generating single photons. FIG. 2, FIG. 3, FIG. 4, FIG. 5 and FIG. 6 show the preparation of the above-mentioned device for generating single photons Schematic diagram of method steps:

First, as shown in FIG. 2 , prepare a substrate 101 first;

Second, prepare a layer of waveguide 102 on the substrate 101, as shown in FIG. 3;

Third, as shown in FIG. 4, a resonant cavity 103 is fabricated on the waveguide 102. Optionally, the resonant cavity 103 can be fabricated using a Complementary Metal Oxide Semiconductor (CMOS) process;

Fourth, optionally, an antenna 104 is fabricated above the waveguide 102 as shown in FIG. 5 . Optionally, the antenna 104 can be fabricated using a CMOS process. The resonant cavity 103 is located at the feeding component of the antenna 104 . That is, the feeding component of the antenna 104 is replaced by the resonant cavity 103;

Fifth, cover a layer of thermosensitive polymer 105 on the surface of the structure, as shown in FIG. 6 . The thermosensitive polymer is hydrophilic under the condition of less than the temperature threshold, and is hydrophobic under the condition of not less than the temperature threshold. Specifically, the thermosensitive polymer 105 has a variety of materials to choose from, such as poly N-isopropylacrylamide (PNIPAM), which will change from hydrophilicity to Hydrophobic.

Fig. 7 exemplarily shows a schematic diagram of the direction A in Fig. 6 provided by the embodiment of the present invention. As shown in Fig. 7, the resonant cavity 103 is a butterfly shape, that is, separated by two sharp corners of two triangular metal pieces The preset distance is formed. The antenna shown in Figure 7 is a Yagi antenna.

Based on the above, FIG. 8 exemplarily shows that an embodiment of the present invention also provides a method for fixing a single photon source in a device for generating single photons, as shown in FIG. 8 , including:

Step 801, irradiating laser light at the resonant cavity on the device for generating single photons;

Step 802, flow into the liquid carrying the single photon source on the surface of the thermosensitive polymer; wherein, the ligands of the quantum dots in the liquid carrying the single photon source are hydrophobic; wherein, the laser is used to: make the quantum dots in the resonant cavity An increase in temperature converts the thermosensitive polymer from hydrophilic to hydrophobic, and attracts the liquid carrying the single photon source to stay in the resonant cavity.

It can be seen that the single photon source can be fixed at the resonant cavity through the above steps 801 and 802, which solves the problem that the single photon source cannot be fixed in the prior art, and provides a basis for controlling the direction of the single photon.

Optionally, the difference between the local oscillator frequency of the antenna and the local oscillator frequency of the single-photon source is smaller than the resonance frequency threshold, so that the local oscillator frequency of the antenna is closer to the local oscillator frequency of the single-photon source, so Resonance can occur where the single-photon source emits light, directing single-photon emission unidirectionally. Optionally, the difference between the local oscillation frequency of the resonant cavity and the local oscillation frequency of the single photon source is smaller than a resonance frequency threshold. In this way, the local oscillation frequency of the resonant cavity is relatively close to that of the single photon source, so resonance can occur under the action of laser light, thereby enhancing the light intensity of the single photon.

In the embodiment of the present invention, an optional manner for determining the materials of the resonant cavity and the antenna is: determining the material of the resonant cavity and the antenna according to the wavelength band where the single photon source is located. For example, when the wavelength band of the laser is in the range from visible light to near-infrared, materials such as gold, silver, copper or aluminum can be used for the resonant cavity and the antenna. When the wavelength band of the laser is in the mid-infrared band, the resonator and the antenna can also use highly doped semiconductors. Optionally, the materials of the resonant cavity and the antenna can be the same or different. When selecting the materials of the resonant cavity and the antenna, the resonant cavity, the antenna and the single photon source should be resonated as much as possible, even if the single photon emitted by the resonant cavity, the antenna and the single photon source have the same local oscillation frequency, which can enhance the single photon light intensity. Optionally, the local oscillator frequency of the antenna can be changed by changing the size of the antenna.

Optionally, a laser is further used to irradiate the resonant cavity, so that the single photon source in the liquid carrying the single photon source staying in the resonant cavity emits a single photon under the irradiation of the laser, and the single photon source Photons are coupled into the waveguide for internal transport.

Optionally, the single-photon source in the liquid carrying the single-photon source is a colloidal quantum dot or a dye molecule. Or the single photon source in the liquid carrying the single photon source is a single photon source synthesized by other chemical means. Optionally, the colloidal quantum dots are group II-VI quantum dots, such as cadmium selenide (CdSe), zinc sulfide (ZnS) and the like. The single photon source in the liquid carrying the single photon source is not limited to II-VI quantum dots, but can also be other semiconductor quantum dots. In this way, on the one hand, the single photon source used in the embodiment of the present invention does not require harsh environmental requirements, such as requiring extremely low ambient temperature, etc., thereby simplifying the production process; on the other hand, the liquid carrying the single photon source can be made The upper surface of the device for generating single photons provided in the embodiment of the present invention flows, thereby successfully implementing the solution provided in the embodiment of the present invention.

In the specific implementation, when the single photon source is a semiconductor quantum dot, due to the extremely small size of the semiconductor quantum dot, with a diameter of several nanometers (nm) to more than ten nm, the wave function of bound electrons in the three-dimensional direction causes it to have Discrete energy levels, and thus semiconductor quantum dots can be used to generate atomic-like dual-level systems. Exciting electrons in semiconductor quantum dots with pump light of the appropriate wavelength causes them to jump from a lower energy level to a higher energy level. When the electron returns to a lower energy level, it emits a photon of fixed energy. Such semiconductor quantum dots can therefore act as "deterministic" single-photon sources, meaning they emit a single photon whenever they are irradiated with a pump pulse.

In the embodiment of the present invention, the ligands of the single-photon sources included in the liquid carrying the single-photon sources can be flexibly changed, such as setting the ligands of the single-photon sources in the liquid carrying the single-photon sources to be hydrophobic .

Based on the same idea, FIG. 9 exemplarily shows a schematic structural diagram of a single photon generation system. As shown in FIG. 9 , the system includes a device for generating single photons, a laser 110 and a liquid inflow device 111, wherein:

The laser 110 is used to irradiate excitation light at the resonant cavity 103 on the device for generating single photons; the liquid inflow device 111 is used to flow in the surface of the thermosensitive polymer 105 to carry a single photon source liquid 106; wherein, the ligand of the single-photon source 107 in the liquid 106 carrying the single-photon source is hydrophobic; wherein, the laser 109 is used for: increasing the temperature in the resonant cavity 103 , changing the thermosensitive polymer in the laser irradiation area from hydrophilic to hydrophobic, and attracting the liquid 106 carrying the single photon source to stay in the resonant cavity 103 .

Optionally, the properties of the thermally sensitive polymer stimulated to change include but not limited to physical or chemical properties such as hydrophilicity and chemical bonds. That is, the thermosensitive polymer will change from hydrophilic to hydrophobic under the change of temperature. Thermosensitive polymers may also have other modifiable physical or chemical properties, among others. As long as the thermosensitive polymer can absorb the single photon source after the properties change, but cannot absorb the single photon source before the properties change.

Further, optionally, when it is necessary to use the device for generating single photons to generate single photons, the single photon source fixed at the center of the resonant cavity can be irradiated with laser light having an energy greater than the bandgap energy of the photon source, so that it emits single photons , the single photon is coupled into the waveguide for internal transmission.

FIG. 10 exemplarily shows a schematic diagram of direction A in FIG. 9 in an embodiment of the present invention, and will be described in detail below in conjunction with FIG. 9 and FIG. 10 .

As shown in FIG. 9 , laser light 109 emitted by a laser 110 is used to irradiate the resonant cavity 103 , and as shown in FIG. 10 , the laser irradiation area 106 covers the resonant cavity 103 . Afterwards, the liquid 106 carrying the single photon source is carried in the liquid inflow device 111, and the liquid 106 carrying the single photon source carried in the liquid inflow device 111 is poured onto the device for generating single photons, specifically, poured into the The surface of thermosensitive polymer 105 . Optionally, pour the liquid 106 carrying the single photon source from the left side of the resonant cavity 103, so that the liquid 106 carrying the single photon source flows through the entire upper surface of the device for generating single photons, and partially from the right side flow out. Optionally, the liquid 106 carrying the single photon source flowing out from the upper surface of the device for generating single photons can flow into a recycling bucket for recycling again.

Optionally, the resonant cavity is a surface plasmon resonant cavity, and due to the plasmonic resonance on the plasmonic surface, the tip of the nanometer metal in the resonant cavity will generate local enhancement. The electrons in the single photon source placed there will produce the Purcell effect (that is, the relaxation time of the electrons in the transition between high and low energy levels will be greatly reduced), which further enhances the brightness of the single photon source.

Optionally, laser light 109 is irradiated above the resonant cavity 103 . As shown in Figure 10, when the laser 109 is irradiated on the resonant cavity 103, the center of the resonant cavity 103 will increase the temperature in a very small space due to the local enhancement of the electric field, thereby causing thermal polymerization in the resonant cavity 103 Material 105 switches from hydrophilic to hydrophobic. Since the ligand of the single photon source is also hydrophobic, when the liquid 106 carrying the single photon source flows through the resonant cavity 103 , the single photon source inside will be absorbed in the resonant cavity 103 . Since the laser heating range is extremely small, and the thermosensitive polymer 105 outside the laser irradiation area 106 is still hydrophilic, the liquid carrying the single photon source flowing through the hydrophilic thermosensitive polymer is used to generate a single Photons flow off the top surface of the device. Optionally, the irradiation range of the laser light is small, and the resonant cavity is also small, and the number of single photons attracted in the resonant cavity may be one. It can be seen that, through the solutions provided by the embodiments of the present invention, the position of the single photon source is accurately controlled, that is, it is fixed in the resonant cavity.

Further, in the embodiment of the present invention, optionally, the resonant cavity and the fixed single photon source in the resonant cavity are located at the feeding component of the antenna. Next, it propagates along a specific direction, thereby achieving the purpose of controlling the propagation direction of the single photon. As shown in FIG. 10 , the single photon 108 will propagate along the right side of the antenna.

Further, since the refractive index of the waveguide 102 is higher than that of the surrounding medium, the single photons generated from the resonant cavity will be trapped in the waveguide 102 with a higher refractive index, thereby realizing the coupling of the single photon and the waveguide.

In the embodiment of the present invention, the device for generating single photons has a simple structure and is easy to manufacture, which simplifies the manufacturing process of the device for generating single photons.

Second, the single photon source can be fixed at the resonant cavity through the device for generating single photons, and the purpose of fixing single photons is realized.

Thirdly, the single photon source is irradiated with a laser with an energy greater than the band gap energy of the single photon source, and the light intensity of the single photon source is further enhanced due to the Purcell effect of the resonant cavity. Figure 11 exemplarily shows a schematic diagram of the light intensity of a single photon in a resonant cavity and the light intensity in free space in an embodiment of the present invention. As shown in Figure 11, when the excitation intensity of the laser is constant, the single photon The light intensity inside the cavity is much greater than that of the single photon in free space.

Fourth, under the action of the antenna, the single photon generated by the single photon source is transmitted along a specific direction, and the purpose of fixing the direction of the single photon is achieved.

Fifth, the device for generating single photons provided by the embodiments of the present invention can successfully couple single photons into the waveguide.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (10)

1. A device for generating single photons, comprising: waveguide; a resonant cavity located above the waveguide, the resonant cavity being irradiated by laser light; A thermally sensitive polymer, located above the waveguide provided with the resonant cavity, the surface of the thermally sensitive polymer is flowed into a liquid carrying a single photon source; wherein, the thermally sensitive polymer is under the condition of less than a temperature threshold It is hydrophilic, and it is hydrophobic when it is not less than the temperature threshold. 2. The device for generating single photons as claimed in claim 1, further comprising: An antenna is located above the waveguide and below the heat-sensitive polymer; wherein, the resonant cavity is located at a feeding component of the antenna. 3. The device for generating single photons according to claim 2, wherein the antenna is a Yagi antenna. 4. The device for generating single photons according to any one of claims 1 to 3, wherein the resonator is a surface plasmon resonator. 5. The device for generating single photons according to any one of claims 1 to 3, wherein the resonant cavity is composed of two metal pieces. 6. The device for generating single photons according to any one of claims 1 to 3, wherein the resonant cavity is formed by any of the following forms: It is formed by a preset distance between two apex corners of two triangular metal parts; it is formed by a double metal nanowire; it is formed by a double metal nano ball. 7. A method for fixing a single photon source in a device for generating single photons based on any one of claims 1 to 6, characterized in that it comprises: Shining laser light at a resonant cavity on a device used to generate single photons; A liquid carrying a single photon source flows into the surface of the thermosensitive polymer; wherein, the ligand of the single photon source in the liquid carrying the single photon source is hydrophobic; Wherein, the laser is used to: increase the temperature in the resonant cavity, convert the thermosensitive polymer from hydrophilic to hydrophobic, and attract the liquid carrying the single photon source to stay in the inside the resonance cavity. 8. The method according to claim 7, wherein the single photon source in the liquid carrying the single photon source is a colloidal quantum dot or a dye molecule. 9. The method according to claim 7, wherein the difference between the local oscillator frequency of the resonant cavity and the local oscillator frequency of the single photon source is less than the resonance frequency threshold; The device for generating single photons further includes a difference between a local oscillator frequency of the antenna and a local oscillator frequency of the single photon source that is smaller than the resonance frequency threshold. 10. A single photon generation system, characterized in that it comprises the device for generating single photons according to any one of claims 1 to 6, a laser and a liquid inflow device, wherein: said laser for illuminating laser light at a resonant cavity on said device for generating single photons; The liquid inflow device is used to flow into the liquid carrying a single photon source on the surface of the thermosensitive polymer; Wherein, the ligand of the single photon source in the liquid carrying the single photon source is hydrophobic; Wherein, the laser is used to: increase the temperature in the resonant cavity, convert the thermosensitive polymer from hydrophilic to hydrophobic, and attract the liquid carrying the single photon source to stay in the The liquid carrying the single-photon source staying in the resonant cavity emits a single photon under the irradiation of the laser, and the single photon is coupled to the waveguide for transmission.