Nanowire laser radiation channel regulation and control method based on asymmetric coupling

Abstract

The invention relates to a nanowire laser radiation channel regulation and control method based on asymmetric coupling, and aims to solve the problems that a laser is large in size, radiation channel regulation and control are rough, and the cost for realizing radiation channel regulation and control of the laser is high. Comprising the following steps: S1, establishing a single nanoparticle and perovskite semiconductor nanowire side wall asymmetric coupling model, and obtaining a simulation result through finite element analysis; s2, analyzing a simulation result of the S1 by adopting a dual-mode approximation theory, adjusting model parameters, realizing regulation and control on CW and CCW traveling wave components, and iterating for multiple times to finally obtain singular point model parameters only having CW or CCW components; and S3, based on the singular point model parameters obtained in the S2, realizing experimental results of a real space and a momentum space in which the single nanoparticle and the side wall of the single perovskite semiconductor nanowire are asymmetrically coupled in an experiment, and analyzing the experimental results. According to the invention, the out-of-plane radiation of echo wall mode laser supported by the cross section of the perovskite semiconductor nanowire can be regulated and controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano laser radiation channels, and specifically provides a method for regulating a nano-wire laser radiation channel based on asymmetric coupling. Background Art

[0002] Since the 21st century, semiconductor micro-nano lasers have developed rapidly. Micro-nano lasers with adjustable radiation channels are of crucial value and significance to the development of cutting-edge scientific and technological fields such as optical sensing, integrated optics, and photonic chips. Perovskite semiconductor nanowires belong to one-dimensional semiconductor luminescent materials, which are small in volume and good in luminescence, and are preferred for making micro-nano lasers. However, due to their micro-nano scale volume and fragile crystal structure, precise regulation of the laser radiation channel is still a challenge for semiconductor nanowire lasers.

[0003] The existing micro-nano laser radiation channel regulation technologies mainly have the following problems: 1. The volume of the laser is large, more than a dozen micrometers or dozens of micrometers, and the on-chip microdisk laser can even reach more than a hundred micrometers; 2. The regulation of the radiation channel is rough, and most of them are in-plane radiation; 3. To achieve the regulation of the radiation channel, the laser needs to be processed later, and the equipment is expensive, resulting in high costs.

[0004] In view of the above problems, a method for regulating a nano-wire laser radiation channel based on asymmetric coupling is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for regulating a nano-wire laser radiation channel based on asymmetric coupling. By using this method, the problems of large volume of the laser, rough regulation of the radiation channel, and high cost for the laser to achieve radiation channel regulation in the above background are solved.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A method for regulating a nano-wire laser radiation channel based on asymmetric coupling, comprising the following steps: S1: Establish a model of asymmetric coupling between a single nanoparticle and the sidewall of a perovskite semiconductor nanowire, and obtain simulation results through finite element analysis; S2: Analyze the simulation results of S1 using the two-mode approximation theory, adjust the model parameters to achieve the regulation of the CW and CCW traveling wave components, and iterate multiple times to finally obtain the singular point model parameters with only CW or CCW components; S3: Based on the singular point model parameters obtained in S2, realize and analyze the experimental results in real space and momentum space of the asymmetric coupling between a single nanoparticle and a single perovskite semiconductor nanowire sidewall in the experiment.

[0007] Further, the specific steps for establishing a model of asymmetric coupling between a single nanoparticle and the sidewall of a perovskite semiconductor nanowire in S1 and obtaining the simulation results through finite element analysis are as follows: S101: Move a nanoparticle and a perovskite semiconductor nanowire to the coupling point in the CW and CCW optical field modes; S102: Use the nanoparticle as a scattering particle to generate asymmetric scattering interference for the CW and CCW traveling waves.

[0008] Further, the specific steps for analyzing the finite element analysis simulation results obtained in S1 using the two-mode approximation theory described in S2 are as follows: S201: During the process of analyzing the finite element analysis simulation results obtained in S1 using the two-mode approximation theory, adjust the parameters and iterate multiple times to obtain extremely unbalanced CW and CCW traveling wave components, that is, reach the singularity point.

[0009] Further, based on the singularity point model parameters obtained in S2 in S3, the specific steps for implementing and analyzing the experimental results in real space and momentum space of the asymmetric coupling between a single nanoparticle and a single perovskite semiconductor nanowire sidewall in the experiment are as follows: S301: The pure standing wave in the resonant cavity will cause laser radiation to exit from the four vertices; S302: Place the perovskite semiconductor nanowire flat on the substrate; S303: Observe the exit conditions of the four vertices 1, 2, 3, and 4, and only the exits of vertices 1 and 2 can be observed; S304: Observe the real space and momentum space, and the obtained results are as follows: In the real space, it can be observed that after the perovskite semiconductor nanowire is asymmetrically coupled via the nanoparticle, bright laser radiation appears at the left top corner, while the laser radiation on the right is very weak; in the momentum space, most of the radiation energy is shown on the left, and there is almost no radiation in the right channel compared to the left channel.

[0010] Further, the perovskite semiconductor nanowire described in S1 uses MAPbBr 3 single crystal perovskite semiconductor nanowire.

[0011] Further, the cross-section of a single MAPbBr 3 single crystal perovskite semiconductor nanowire can support two types of whispering gallery mode resonances, namely CW and CCW modes.

[0012] Further, the CW mode and the CCW mode are symmetrically balanced resonances when not disturbed.

[0013] Furthermore, when the CW mode and the CCW mode are in symmetric balanced resonance, the CW traveling wave component is consistent with the CCW traveling wave component, and 100% pure standing waves can be formed in the resonant cavity.

[0014] Furthermore, when the CW traveling wave component and the CCW traveling wave component are in an extremely unbalanced state and reach the singularity, only the CW traveling wave component or only the CCW traveling wave component exists in the resonant cavity.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Based on MAPbBr 3 Asymmetric coupling of single-crystalline perovskite semiconductor nanowires and nanoparticles, and 3 Effective radiation channel regulation of the whispering gallery mode laser supported by the cross-section of MAPbBr 3 single-crystalline perovskite semiconductor nanowires enables out-of-plane lasing regulation, and 3 single-crystalline perovskite semiconductor nanowires only need to have asymmetric coupling with a single nanoparticle to achieve the regulation of the out-of-plane radiation of the whispering gallery mode laser supported by the cross-section of MAPbBr BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A three-dimensional view of a MAPbBr 3 single-crystalline perovskite semiconductor nanowire used in the present invention; Figure 2 A three-view drawing of a MAPbBr 3 single-crystalline perovskite semiconductor nanowire used in the present invention; Figure 3 A schematic diagram of the whispering gallery mode resonance and laser emission supported by the cross-section of a single MAPbBr 3 single-crystalline perovskite semiconductor nanowire used in the present invention; Figure 4 A light field simulation diagram of the whispering gallery mode of a cross-section of a MAPbBr 3 single-crystalline perovskite semiconductor nanowire used in the present invention; Figure 5 A schematic diagram of the asymmetric coupling of a nanoparticle and the side wall of a MAPbBr 3 single-crystalline perovskite semiconductor nanowire used in the present invention; Figure 6 A schematic diagram of the resonant cavity in the present invention having both standing wave components and traveling wave components; Figure 7 A schematic diagram of the resonant cavity in the present invention having only CW traveling wave components; Figure 8 For this Figure 7Schematic diagram of the Husimi transform of the CW traveling wave component; Figure 9 MAPbBr flat on the substrate for the present invention 3 Schematic diagram of the cross-sectional radiation channel of a single-crystalline perovskite semiconductor nanowire of the present invention; Figure 10 Schematic diagram of the situation where only the CW traveling wave component exists inside the square cavity and only 1 remains in the output channel after achieving singularity coupling in the present invention; Figure 11 In the present invention for experimental verification of MAPbBr 3 Schematic diagram of the real-space micrograph of lasing from a single-crystalline perovskite semiconductor nanowire; Figure 12 In the present invention for experimental verification of MAPbBr 3 Schematic diagram of the momentum-space photograph of lasing from a single-crystalline perovskite semiconductor nanowire; Figure 13 Overall flowchart of the present invention; Figure 14 In the present invention for nanoparticles and MAPbBr 3 Specific flowchart of the asymmetric coupling of the sidewalls of a single-crystalline perovskite semiconductor nanowire; Figure 15 Specific flowchart of the theoretical analysis results of the two-mode approximation in the present invention; Figure 16 Specific flowchart of the experimental results of observing the real space and momentum space in the present invention. Specific embodiments

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] To solve the technical problems of large laser volume, rough regulation of radiation channels, and high cost for a laser to achieve radiation channel regulation, as Figure 1 - Figure 16 shown, the following preferred technical solutions are provided: A method for regulating the laser radiation channel based on asymmetric coupling, comprising the following steps: S1: Establish a model of the asymmetric coupling of a single nanoparticle and the sidewall of a perovskite semiconductor nanowire, and obtain the simulation results through finite element analysis; S2: Analyze the simulation results of S1 using the two-mode approximation theory, adjust the model parameters to achieve the regulation of the CW and CCW traveling wave components, iterate multiple times, and finally obtain the singular point model parameters with only CW or CCW components. S3: Based on the singular point model parameters obtained in S2, implement and analyze the experimental results in real space and momentum space of the asymmetric coupling between a single nanoparticle and the sidewall of a single perovskite semiconductor nanowire in the experiment.

[0019] The specific steps to establish the model of the asymmetric coupling between a single nanoparticle and the sidewall of a single perovskite semiconductor nanowire described in S1 and obtain the simulation results through finite element analysis are as follows: S101: Propagate a nanoparticle and a perovskite semiconductor nanowire to the coupling point in the CW and CCW optical field modes. S102: Use the nanoparticle as a scattering particle to generate asymmetric scattering interference for the CW and CCW traveling waves.

[0020] The specific steps to analyze the finite element analysis simulation results obtained in S1 using the two-mode approximation theory described in S2 are as follows: S201: During the process of analyzing the finite element analysis simulation results obtained in S1 using the two-mode approximation theory, regulate the parameters and iterate multiple times to obtain extremely unbalanced CW and CCW traveling wave components, that is, reach the singular point.

[0021] The specific steps to implement and analyze the experimental results in real space and momentum space of the asymmetric coupling between a single nanoparticle and the sidewall of a single perovskite semiconductor nanowire based on the singular point model parameters obtained in S2 in S3 are as follows: S301: The pure standing wave in the resonant cavity will cause laser radiation to exit from the four vertices. S302: Place the perovskite semiconductor nanowire flat on the substrate. S303: Observe the exit conditions of the four vertices 1, 2, 3, and 4, and only the exits of vertices 1 and 2 can be observed. S304: Observe the real space and momentum space, and the obtained results are as follows: In the real space, it can be observed that after the perovskite semiconductor nanowire is asymmetrically coupled via the nanoparticle, there is bright laser radiation at the left top corner, while the laser radiation on the right is very weak; in the momentum space, most of the radiation energy is shown on the left, and there is almost no radiation in the right channel compared to the left channel.

[0022] The perovskite semiconductor nanowire described in S1 uses MAPbBr 3 single crystal perovskite semiconductor nanowire.

[0023] Single MAPbBr 3The cross-section of a single-crystalline perovskite semiconductor nanowire can support two types of whispering-gallery mode resonances, namely the CW and CCW modes.

[0024] When undisturbed, the CW mode and the CCW mode are symmetrically balanced resonances.

[0025] When the CW mode and the CCW mode are in symmetrically balanced resonance, the CW traveling-wave component is consistent with the CCW traveling-wave component, and a 100% pure standing wave can be formed in the resonant cavity.

[0026] When the CW traveling-wave component and the CCW traveling-wave component are in an extremely unbalanced state, a singularity point is reached, and only the CW traveling-wave component or only the CCW traveling-wave component exists in the resonant cavity.

[0027] To better illustrate the above embodiments, the specific experimental steps are as follows: This method uses MAPbBr 3 single-crystalline perovskite semiconductor nanowires for experiments. The stereogram and three-view drawings of the MAPbBr 3 single-crystalline perovskite semiconductor nanowires are respectively as Figure 1 and Figure 2 shown; as Figure 3 shown, the cross-section (front view) of a single MAPbBr 3 single-crystalline perovskite semiconductor nanowire can support two types of whispering-gallery mode resonances, namely the CW mode that rotates clockwise and the CCW mode that rotates counterclockwise. Lasers radiate outward from the four vertices 1, 2, 3, and 4 respectively. Without external interference, since the CW mode and the CCW mode are in a symmetrically balanced resonance state, the four radiation channels 1, 2, 3, and 4 are consistent. Since the CW traveling-wave component is consistent with the CCW traveling-wave component, a 100% pure standing wave can be formed in the resonant cavity (the finite element analysis simulation results are as Figure 4 shown).

[0028] Now, a nanoparticle and the side wall of a MAPbBr 3 single-crystalline perovskite semiconductor nanowire are asymmetrically coupled (as Figure 5 shown); the above-mentioned asymmetric coupling means that when a nanoparticle and a MAPbBr 3 single-crystalline perovskite semiconductor nanowire travel to the coupling point in the CW and CCW optical field modes, using the nanoparticle as a scattering particle (or as an externally introduced interference), the scattering interference on the CW and CCW traveling waves is generated, resulting in the CW and CCW traveling-wave components running in the resonant cavity no longer being consistent and presenting an asymmetric coupling phenomenon; the finite element analysis simulation results are as Figure 6As shown, it can be observed that there is no longer a 100% pure standing wave in the resonant cavity, but there is a partial traveling wave component, which is caused by the imbalance between the CW and CCW traveling wave components.

[0029] This method uses the two-mode approximation theory to analyze the phenomenon that there is no longer a 100% pure standing wave in the resonant cavity, and further adjusts the parameters to make the imbalance between the CW and CCW traveling wave components reach the extreme. When the CW and CCW traveling wave components are in the extreme imbalance state, only the CW traveling wave component or only the CCW traveling wave component will exist, that is, the singularity point is reached. Taking the case where only the CW traveling wave component exists as an example, the simulation results of the optical field distribution are as Figure 7 shown, and the corresponding Husimi transform of the optical field is as Figure 8 shown. It can be observed that all the optical field energy is concentrated in the region where sinX is from -1 to 0, that is, the CW component region.

[0030] The 100% pure standing wave formed by the CW mode and CCW mode in the resonant cavity will cause laser radiation to exit from the four vertices 1, 2, 3, and 4 respectively. If the MAPbBr 3 single-crystalline perovskite semiconductor nanowire is placed flat on the substrate, as Figure 9 shown, we will observe the exit from vertices 1 and 2, and the energy exiting from 3 and 4 will leak into the substrate. Therefore, it can be judged that the available energy only comes out from 1 and 2. After the asymmetric coupling of the scattering particles (as Figure 10 shown), only vertex 1 radiates outward. Therefore, the regulation of the laser radiation channel based on the asymmetric coupling of the MAPbBr 3 single-crystalline perovskite semiconductor nanowire and nanoparticles is realized.

[0031] Observing the experimental results in real space ( Figure 11 ) and momentum space ( Figure 12 ), it can be judged that only one channel radiates outward. In real space, it can be observed that after the asymmetric coupling of the MAPbBr 3 single-crystalline perovskite semiconductor nanowire and nanoparticles, bright laser radiation appears at the left top corner, while the laser radiation on the right is very weak; a similar pattern can also be observed in momentum space. The picture in momentum space shows that most of the radiation energy is on the left, and there is almost no radiation energy in the right channel compared to the left channel.

[0032] The discussion on material replacement in the present invention is as follows: Selection of nanoparticles: It can be nanomaterials such as gold particles and single silicon pillars with high refractive index and good scattering performance.

[0033] Replacement of nanowire materials: Such as MAPbBr 3The perovskite semiconductor nanowires can be replaced with other perovskite nanowires or other semiconductor nanowires with direct band gaps, etc.

[0034] Selection of the substrate: It can be common substrates with low refractive indices such as SiO 2 , Al 2 O 3 and so on.

[0035] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0036] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for regulating nanowire laser radiation channels based on asymmetric coupling, characterized in that: The following steps are involved: S1: Establish a model of asymmetric coupling between a single nanoparticle and the sidewall of a perovskite semiconductor nanowire, and obtain simulation results through finite element analysis; S2: Use the dual-mode approximation theory to analyze the simulation results of S1, adjust the model parameters, and achieve the control of CW and CCW traveling wave components. After multiple iterations, finally obtain the singular point model parameters with only CW or CCW components; S3: Based on the singular point model parameters obtained in S2, the experimental results of the asymmetric coupling between a single nanoparticle and the side wall of a single perovskite semiconductor nanowire in real space and momentum space are realized and analyzed.

2. The method for controlling a nanowire laser radiation channel based on asymmetric coupling according to claim 1, characterized in that: The specific steps of establishing the model of asymmetric coupling between a single nanoparticle and the sidewall of a perovskite semiconductor nanowire described in S1 and obtaining the simulation results through finite element analysis are as follows: S101: A nanoparticle and a perovskite semiconductor nanowire are guided to a coupling point in CW and CCW optical field modes; S102: Using nanoparticles as scattering particles to generate asymmetric scattering interference on CW and CCW traveling waves.

3. The method for controlling a nanowire laser radiation channel based on asymmetric coupling according to claim 2, characterized in that: The specific steps of analyzing the finite element analysis simulation results obtained in S1 using the dual-mode approximation theory described in S2 are as follows: S201: In the process of analyzing the finite element analysis simulation results obtained in S1 using the dual-mode approximation theory, the parameters are adjusted and iterated multiple times to obtain extremely unbalanced CW and CCW traveling wave components, that is, to reach the singularity point.

4. The method for controlling a nanowire laser radiation channel based on asymmetric coupling according to claim 3, characterized in that: In S3, based on the singular point model parameters obtained in S2, the specific steps of realizing the experimental results of asymmetric coupling between a single nanoparticle and the side wall of a single perovskite semiconductor nanowire in real space and momentum space and analyzing them are as follows: S301: Pure standing waves in the resonant cavity will cause laser radiation to emerge from the four vertices; S302: placing the perovskite semiconductor nanowire flat on a substrate; S303: Observe the emission conditions of the four vertices 1, 2, 3 and 4, and only the emission of the two vertices 1 and 2 can be observed; S304: Observe the real space and momentum space, and the results are as follows: In the real space, it can be observed that after the perovskite semiconductor nanowires are asymmetrically coupled through nanoparticles, bright laser radiation appears at the left top corner, while the laser radiation on the right is very weak; the left side of the momentum space shows most of the radiation energy, and compared with the left channel, the right channel has almost none.

5. The method for controlling a nanowire laser radiation channel based on asymmetric coupling according to claim 4, characterized in that: The perovskite semiconductor nanowire described in S1 uses MAPbBr3 single crystal perovskite semiconductor nanowire.

6. The method for controlling a nanowire laser radiation channel based on asymmetric coupling according to claim 5, characterized in that: The cross-section of a single MAPbBr3 single-crystal perovskite semiconductor nanowire can support two types of whispering gallery mode resonances, namely CW and CCW modes.

7. The method for controlling a nanowire laser radiation channel based on asymmetric coupling according to claim 6, characterized in that: The CW mode and CCW mode are symmetrical and balanced resonances when not disturbed.

8. The method for controlling nanowire laser radiation channels based on asymmetric coupling according to claim 7, characterized in that: When the CW mode and the CCW mode are in symmetrical balanced resonance, the CW traveling wave component is consistent with the CCW traveling wave component, and a 100% pure standing wave can be formed in the resonant cavity.

9. The method for controlling nanowire laser radiation channels based on asymmetric coupling according to claim 8, characterized in that: When the CW traveling wave component and the CCW traveling wave component are in an extremely unbalanced state, a singular point is reached, and only the CW traveling wave component or only the CCW traveling wave component exists in the resonant cavity.

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