Method and device for multi-wavelength excitation micro-nanocrystal luminescence modulation

Abstract

The application provides a method and device for multi-wavelength excitation micro-nano crystal luminescence regulation, which comprises the following steps: determining the wavelength of continuous laser for capturing a single micro-nano crystal according to the absorption spectrum of a rare earth doped micro-nano crystal; determining the wavelength of each pulse excitation laser corresponding to the absorption spectrum of each type of doped ion; emitting the continuous laser to the micro-nano crystal to capture a single micro-nano crystal; regulating the excitation sequence and time interval of each pulse excitation laser emitted to the micro-nano crystal through timing to obtain the electron population process and fluorescence emission timing of the micro-nano crystal under the excitation of each pulse excitation laser. Different fluorescence appearance sequences reflect different electron population processes and electron accumulation conditions on different energy levels in the micro-nano crystal.

Description

Technical Field

[0001] This invention belongs to the field of transient emission spectroscopy detection technology of micro-nano-sized materials based on optical tweezers, and specifically relates to a method and device for multi-wavelength excitation of micro-nano crystal luminescence modulation. Background Technology

[0002] With the development of micro / nano crystal synthesis technology, micro / nano luminescent materials are increasingly finding wide applications in fields such as bioimaging, anti-counterfeiting, temperature detection, and laser materials. Lanthanide-doped micro / nano crystals, due to the energy resonance phenomenon between lanthanide ions, exhibit multidimensionally tunable luminescence properties. However, current theoretical models are not yet fully developed and cannot completely predict the luminescence of lanthanide-doped micro / nano crystals. The limited acquisition of kinetic spectral information for lanthanide-doped micro / nano crystals is one of the important reasons for the incompleteness of prediction models. Furthermore, the small size of lanthanide-doped micro / nano crystals results in relatively weak luminescence, making the characterization of their related kinetic processes crucial for materials research and applications.

[0003] In 1986, Ashkin, a scientist at Bell Labs in the United States, invented optical tweezers. Optical tweezers utilizes the momentum transfer during the interaction between light and matter. By focusing a beam of light to create a localized hotspot in three-dimensional space, and under the influence of gradient forces, it enables the manipulation of the three-dimensional spatial position of tiny materials near this hotspot. This technology has significant advantages for achieving three-dimensional control of micro- and nano-crystals. High time-resolution transient emission spectrum acquisition technology refers to the acquisition of the time spectrum of the analyte after pulsed laser excitation, specifically the spectrum of one or more time intervals following excitation. High time resolution is reflected in the minimum interval of this time interval, also known as the sampling gate width. A characterization platform combining optical tweezers technology with high time-resolution transient excitation spectrum acquisition technology can effectively obtain the dynamic spectral information of micro- and nano-crystals. Summary of the Invention

[0004] Based on the current state of the technology, this invention provides a novel method and apparatus for controlling the luminescence of micro / nano crystals through multi-wavelength excitation.

[0005] To achieve the above-mentioned technical objectives, the technical solution proposed by this invention is as follows:

[0006] On one hand, the present invention provides a method for controlling the luminescence of micro / nano crystals through multi-wavelength excitation, comprising:

[0007] Based on the absorption spectrum of the micro / nano crystal, the wavelength of continuous laser light used to capture a single micro / nano crystal is determined.

[0008] Based on the type of doped ions in the micro / nano crystal, determine the wavelength of each pulse excitation laser corresponding to the absorption spectrum of each type of doped ion.

[0009] A continuous laser beam is emitted onto the micro / nano crystal to capture a single micro / nano crystal.

[0010] By controlling the timing of the excitation sequence and time interval of each pulse of excitation laser emitted onto the micro / nano crystal, the order in which different fluorescence appears under the excitation of each pulse of excitation laser is obtained.

[0011] Furthermore, the principle for determining the continuous laser wavelength in this invention is that the micro / nano crystal does not absorb continuous laser light of that wavelength.

[0012] Furthermore, the number of pulsed excitation lasers and the wavelength of each pulsed excitation laser are determined by the type of doping ions in the micro / nano crystal. The determination principle is that each pulsed excitation laser is absorbed by at least one type of doping ion in the micro / nano crystal, and each type of doping ion in the micro / nano crystal absorbs at least one wavelength of pulsed excitation laser.

[0013] Furthermore, the micro / nano crystal described in this invention is a micro / nano crystal doped with rare earth Yb-Er ions.

[0014] Furthermore, for micro / nano crystals doped with rare-earth Yb-Er ions, the continuous laser described in this invention uses a laser with a wavelength of 1342 nm.

[0015] Furthermore, the pulsed excitation laser of the present invention includes an 808nm pulsed laser. When the 808nm pulsed laser excites the micro / nano crystal doped with rare earth Yb-Er ions, the Er ions absorb the 808nm light and obtain different fluorescence appearance times. The different fluorescence appearance times reflect the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

[0016] Furthermore, the pulsed excitation laser of the present invention includes a 976nm pulsed laser. When the 976nm pulsed laser excites the micro / nano crystal doped with rare earth Yb-Er ions, both Er ions and Yb ions absorb the 976nm light, resulting in different fluorescence appearance times. The different fluorescence appearance times reflect the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

[0017] On the other hand, the present invention provides a device for multi-wavelength excited micro / nano crystal luminescence modulation, comprising:

[0018] The sample chamber is used to hold micro / nano crystals.

[0019] A continuous laser emission optical path is used to emit a continuous laser beam to the micro / nano crystal to capture a single micro / nano crystal, wherein the wavelength of the continuous laser beam used to capture the single micro / nano crystal is determined based on the absorption spectrum of the micro / nano crystal.

[0020] The pulsed laser emission and control optical path is used to control the excitation order and time interval of each pulsed excitation laser emitted onto the micro / nano crystal, thereby obtaining the order in which different fluorescence appears under the excitation of each pulsed excitation laser. The wavelength of each pulsed excitation laser is determined according to the type of doped ions in the micro / nano crystal and the absorption spectrum of each type of doped ion.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] In this invention, continuous laser is used to locate micro / nano crystals, i.e., continuously captured laser is used as optical tweezers to control micro / nano crystals in three dimensions. Pulsed excitation laser is used to excite doped ions in the micro / nano crystal to produce fluorescence with different temporal attributes, i.e., to obtain the order in which different fluorescence appears under the excitation of pulsed excitation laser. The order in which different fluorescence appears reflects the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

[0023] This invention provides a device for controlling the luminescence of micro / nano crystals through multi-wavelength excitation. Under the action of optical tweezers, it can realize the control and real-time monitoring of the three-dimensional spatial position of micro / nano-sized materials (i.e., micro / nano crystals), obtain the temporal sequence of different fluorescence under the excitation of pulsed laser, and also collect transient excitation spectra and continuous excitation spectra with high time resolution and high wavelength resolution. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a flowchart of an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of a structure according to an embodiment of the present invention;

[0027] Numbering on the map:

[0028] 1. Continuous capture laser; 2. First plano-convex lens; 3. Second plano-convex lens; 4. First half-wave plate; 5. First plane mirror; 6. First pulse-excited laser; 7. Third plano-convex lens; 8. Fourth plano-convex lens; 9. Second half-wave plate; 10. Second plane mirror; 11. Second pulse-excited laser; 12. Fifth plano-convex lens; 13. Sixth plano-convex lens; 14. Third half-wave plate; 15. First beam combiner; 16. Second beam combiner; 17. Quarter-wave plate; 18. Dichroic mirror; 19. First objective lens; 20. Second objective lens; 21. Illumination device; 22. Three-dimensional displacement platform; 23. Beam splitter; 24. Color CMOS camera; 25. Seventh plano-convex lens; 26. Spectrometer; 27. Digital delay synchronization trigger; 28. Computer. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the spirit of the disclosed content will be clearly explained below with reference to the accompanying drawings and detailed description. Any person skilled in the art, after understanding the embodiments of the present invention, can make changes and modifications based on the techniques taught in the present invention without departing from the spirit and scope of the present invention. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0030] Reference Figure 1 According to one embodiment of the present invention, a method for controlling the luminescence of micro / nano crystals by multi-wavelength excitation is provided, comprising:

[0031] Based on the absorption spectrum of the micro / nano crystal, the wavelength of continuous laser light used to capture a single micro / nano crystal is determined.

[0032] Based on the type of doped ions in the micro / nano crystal, determine the wavelength of each pulse excitation laser corresponding to the absorption spectrum of each type of doped ion.

[0033] A continuous laser beam is emitted onto the micro / nano crystal to capture a single micro / nano crystal.

[0034] By controlling the timing of the excitation sequence and time interval of each pulse of excitation laser emitted onto the micro / nano crystal, the order in which different fluorescence appears under the excitation of each pulse of excitation laser is obtained.

[0035] In the above embodiments, the principle for determining the continuous laser wavelength is that the micro / nano crystal does not absorb continuous laser light of that wavelength.

[0036] In the above embodiments, the number of pulsed excitation lasers and the wavelength of each pulsed excitation laser are determined by the doping ion type of the micro / nano crystal. The determination principle is that each pulsed excitation laser is absorbed by at least one type of doping ion in the micro / nano crystal, and each type of doping ion in the micro / nano crystal absorbs at least one wavelength of pulsed excitation laser.

[0037] In another embodiment, a method for modulating the luminescence of micro / nano crystals using multi-wavelength excitation is provided, comprising:

[0038] The micro / nano crystal is a micro / nano crystal doped with rare earth Yb-Er ions. Based on the absorption spectrum of the micro / nano crystal, the wavelength of the continuous laser used to capture a single micro / nano crystal is determined, wherein the continuous laser is a laser with a wavelength of 1342 nm.

[0039] Based on the doping ion type of the micro / nano crystal, the wavelengths of each pulsed excitation laser corresponding to the absorption spectra of each type of doping ion are determined. The pulsed excitation lasers include 808nm pulsed lasers and 976nm pulsed lasers. Er ions absorb 808nm light, while both Er and Yb ions absorb 976nm light.

[0040] A continuous laser beam is emitted onto the micro / nano crystal to capture a single micro / nano crystal.

[0041] By controlling the timing of the excitation sequence and time interval of each pulse of excitation laser emitted onto the micro / nano crystal, the order in which different fluorescence appears under the excitation of each pulse of excitation laser is obtained.

[0042] When the micro / nano crystal doped with rare-earth Yb-Er ions is excited by an 808nm pulsed laser, the Er ions absorb the 808nm light and obtain different fluorescence appearance times. The different fluorescence appearance times reflect the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

[0043] When the micro / nano crystal doped with rare-earth Yb-Er ions is excited by a 976nm pulsed laser, both Er and Yb ions absorb the 976nm light, resulting in different sequences of fluorescence appearance. The sequence of fluorescence appearance reflects the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

[0044] In one embodiment, a device for multi-wavelength excited micro / nano crystal luminescence modulation is provided, comprising:

[0045] The sample chamber is used to hold micro / nano crystals.

[0046] A continuous laser emission optical path is used to emit a continuous laser beam to the micro / nano crystal to capture a single micro / nano crystal, wherein the wavelength of the continuous laser beam used to capture the single micro / nano crystal is determined based on the absorption spectrum of the micro / nano crystal.

[0047] The pulsed laser emission and control optical path is used to obtain the order in which different fluorescence appears under the excitation of each pulsed excitation laser by controlling the excitation sequence and time interval of each pulsed excitation laser onto the micro / nano crystal.

[0048] The design of continuous laser emission optical path and pulsed laser emission and control optical path can be realized by those skilled in the art based on existing technology. Furthermore, by designing the optical path transmission path, a portion of the continuous laser emission optical path and pulsed laser emission and control optical path can be provided to reduce the use of optical devices. The specific design method is not limited.

[0049] Reference Figure 2 One embodiment provides a device for controlling the luminescence of a multi-wavelength excited micro / nano crystal, comprising: a sample manipulation module, a continuous laser emission optical path, an illumination light device, a pulsed laser emission module, a dichroic mirror, a beam splitter prism, a timing control module, a data recording module, a color CMOS camera, and a spectral analysis module.

[0050] The sample manipulation module includes a sample cavity, a three-dimensional displacement platform 22, a first objective lens 19 and a second objective lens 20. The micro-nano crystal is placed in the sample cavity, which is located on the three-dimensional displacement platform 22.

[0051] The continuous light excitation module includes a continuous capture laser 1, which emits a continuous laser beam, expands the beam, adjusts the polarization angle, and directs it onto a first objective lens 19. The first objective lens 19 focuses the laser onto a micro / nano crystal within the sample cavity on a three-dimensional displacement platform 22. The continuous laser beam is expanded to the size of the entrance pupil of the first objective lens. The continuous laser is used to capture a single micro / nano crystal. The wavelength of the continuous laser used to capture the single micro / nano crystal is determined based on the absorption spectrum of the micro / nano crystal, with the principle that the micro / nano crystal does not absorb the continuous laser of that wavelength.

[0052] The illumination device 21 is used to emit illumination light and focus the illumination light into a large spot through the second objective lens 20 to illuminate the sample cavity; the continuous sample fluorescence generated by continuous laser focusing and the illumination light enter the color CMOS camera 24 through the first objective lens 19, the dichroic mirror 18 and the beam splitter prism 23, and image the micro-nano crystal in the sample cavity onto the color CMOS camera 24.

[0053] The pulsed laser emission module emits pulsed excitation lasers of different wavelengths. A timing controller precisely controls the excitation sequence and time interval of each pulsed excitation laser emitted onto the micro / nano crystal. Specifically, based on the type of dopant ions in the micro / nano crystal, the wavelength of each pulsed excitation laser corresponding to the absorption spectrum of each type of dopant ion is determined. The principle is that each pulsed excitation laser is absorbed by at least one type of dopant ion in the micro / nano crystal, and each type of dopant ion in the micro / nano crystal absorbs at least one wavelength of pulsed excitation laser.

[0054] Reference Figure 1 The continuous light excitation module includes a continuous-wave laser 1 with a low-absorption wavelength from a micro / nano crystal, a first beam-expanding lens group, and a first half-wave plate 4. The continuous laser emitted from the continuous-wave laser 1 is expanded by the first beam-expanding lens group, its polarization angle is adjusted by the first half-wave plate 4, and then it passes through a second beam combiner 16, a quarter-wave plate 17, and a dichroic mirror 18 before being incident on a first objective lens 19. The first objective lens 19 focuses the laser beam onto the micro / nano crystal within the sample cavity on a three-dimensional displacement platform 22, expanding the continuous laser beam to the size of the entrance pupil of the first objective lens. The continuous laser is used to capture individual micro / nano crystals. The wavelength of the continuous laser used to capture individual micro / nano crystals is determined based on the absorption spectrum of the micro / nano crystals. The first beam-expanding lens group consists of a first plano-convex lens 2 and a second plano-convex lens 3 arranged coaxially and opposite to each other.

[0055] Reference Figure 2 , Figure 2 The device shown includes a first pulse excitation laser 6 and a second pulse excitation laser 11. The first pulse excitation laser emitted by the first pulse excitation laser 6 is expanded by the second beam expander lens group, and then its polarization is adjusted by the second half-wave plate 9. After passing through the second plane mirror 10, the first beam combiner 15, the second beam combiner 16, and the quarter-wave plate 17, it is incident on the first objective lens 19 and focused by the first objective lens 19. The focal point is located on the micro-nano crystal in the sample cavity on the three-dimensional displacement platform 22. The second beam expander lens group consists of a third plano-convex lens 7 and a fourth plano-convex lens 8 that are coaxial and arranged opposite each other.

[0056] The second pulse excitation laser emitted by the second pulse excitation laser 11 is expanded by the third beam expanding lens group, and then its polarization is adjusted by the third half-wave plate 14. After passing through the first beam combiner 15, the second beam combiner 16, the quarter-wave plate 17, and the dichroic mirror 18, it is incident on the first objective lens 19 and focused by the first objective lens 19. The focal point is located on the micro-nano crystal in the sample cavity on the three-dimensional displacement platform 22. The third beam expanding lens group consists of a fifth plano-convex lens 12 and a sixth plano-convex lens 13 that are coaxial and arranged opposite to each other.

[0057] The spectral analysis module includes a seventh plano-convex lens 25 and a spectrometer 26. The light beam incident on the seventh plano-convex lens 25 is focused by the seventh plano-convex lens 25 onto the entrance slit of the spectrometer 26.

[0058] The timing control module controls the activation timing, duration, and interval of the spectrometer 26, the continuous capture laser in the continuous light excitation module, and the pulsed excitation lasers in the pulsed laser emission module. This ensures that the spectrometer 26 collects the transient excitation spectra of the micro / nano crystal at different times after being excited by the pulsed laser. In some embodiments, the timing control module employs a digital delay synchronization trigger 27 to achieve synchronous triggering of the spectrometer and the pulsed excitation laser. The data recording module uses a computer 28. By controlling the spectrometer 26 and the pulsed excitation laser through the timing control module, the excitation light collection module collects the spectrum for a specific time period after the desired pulse excitation. By precisely setting the timing control and data recording modules, the fluorescence spectrum process can be recorded segment by segment through multiple excitations, ultimately obtaining the time spectrum of fluorescence decay within a certain wavelength band. This ultimately achieves 1-micron three-dimensional spatial manipulation of the micro / nano crystal, a minimum spectral integration gate width of 2 ns, a step size of 10 ps, ​​a real-time imaging monitoring image resolution of 500 nm, and a maximum spectral resolution of 0.01 nm.

[0059] In one embodiment, the first objective lens 19 is a 100x objective lens. The second objective lens 21 is a 20x objective lens.

[0060] In one embodiment, the illumination device 21 is a white LED, and the white light is focused into a large spot by a 20x objective lens to illuminate the sample cavity.

[0061] In one embodiment of the present invention, based on Figure 2 The apparatus provided in the illustrated embodiment offers a method for modulating the luminescence of micro / nano crystals using multi-wavelength excitation, comprising the following steps:

[0062] A micro / nanocrystal is prepared and placed in a sample cavity located on a three-dimensional displacement platform. The micro / nanocrystal is doped with rare-earth Yb-Er ions. Based on the absorption spectrum of the micro / nanocrystal, the wavelength of the continuous laser used to capture a single micro / nanocrystal is determined. The continuous laser output is a 1342 nm laser. The 1342 nm laser acts as optical tweezers to capture a single micro / nanocrystal; it has no effect on energy level modulation, primarily because the Yb-Er system absorbs 1342 nm laser light very poorly.

[0063] Based on the doping ion type of the micro / nano crystal, the wavelength of each pulse-excited laser corresponding to the absorption spectrum of each type of doping ion is determined. The first pulse-excited laser outputs an 808nm pulse laser, the second pulse-excited laser outputs a 976nm pulse laser, Er ions absorb 808nm light, and both Er and Yb ions absorb 976nm light.

[0064] The continuous capture laser is turned on and emits a 1342nm laser. The 1342nm laser beam is expanded and the polarization angle is adjusted before it is incident on the first objective lens and focused by the first objective lens. The focal point is located on the micro-nano crystal in the sample cavity on the three-dimensional displacement platform. The continuous laser beam is expanded to the size of the entrance pupil of the first objective lens.

[0065] The illumination device is turned on to emit illumination light, which is focused into a large spot by the second objective to illuminate the sample cavity; the continuous fluorescence generated by the continuous laser focusing and the illumination light enter the color CMOS camera through the first objective, dichroic mirror and beam splitter, and image the micro-nano crystal in the sample cavity onto the color CMOS camera.

[0066] Manipulate the three-dimensional displacement platform to bring the micro / nano crystal into the potential well formed by the continuous laser, and then turn off the continuous trap laser and the illumination device;

[0067] The first pulse excitation laser is activated, outputting an 808nm pulsed laser light to the micro / nano crystal. This 808nm light excites the rare-earth Yb-Er ion-doped micro / nano crystal, specifically the NaYF4:Yb / Er micro / nano crystal. The Er ions primarily absorb the 808nm light, undergoing an electron population process from C-1 to C-7 according to the order in which different fluorescence appears. This electron population process exhibits a sequential emission phenomenon, meaning that fluorescence of different wavelengths appears one after another over time, following the sequence of the electron population process. The transient excitation spectra of the micro / nano crystal at different moments after being excited by the pulsed laser are continuously observed and recorded using a color CMOS camera.

[0068] The second pulse excitation laser is turned on, and a 976nm pulse laser is output to the micro-nano crystal. Both Er and Yb ions absorb the 976nm fluorescence. According to the order of the appearance of different fluorescence, the corresponding electron population process occurs. The transient excitation spectrum of the micro-nano crystal at different times after being excited by the pulse excitation laser is continuously observed and recorded by a color CMOS camera.

[0069] The sequential appearance of different fluorescence spectroscopy events reflects different electron population processes and electron accumulation at different energy levels. By using 976 nm and 808 nm lasers at different excitation times, the electron population process and fluorescence emission sequence within the Yb-Er system can be effectively controlled. Therefore, by controlling the excitation sequence and time interval of the 976 nm and 808 nm lasers, different fluorescence appearance sequences can be regulated, reflecting different electron population processes, thus achieving multi-beam electron population process control.

[0070] The advantages of the method and apparatus provided by this invention are also reflected in:

[0071] (1) The present invention can directly detect the spectral characteristics of a single micro / nano crystal;

[0072] (2) This invention combines high temporal resolution, high spatial resolution and high wavelength resolution to perform comprehensive spectral analysis;

[0073] (3) The present invention can realize real-time dynamic monitoring in the detection process of micro-nano crystals;

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for modulating the luminescence of micro / nano crystals using multi-wavelength excitation, characterized in that, include: Based on the absorption spectrum of the micro / nano crystal, the wavelength of the continuous laser used to capture a single micro / nano crystal is determined, wherein the principle for determining the wavelength of the continuous laser is that the micro / nano crystal does not absorb the continuous laser of that wavelength. Based on the doping ion type of the micro / nano crystal, the wavelength of each pulse excitation laser corresponding to the absorption spectrum of each type of doping ion is determined. The number of pulse excitation lasers and the wavelength of each pulse excitation laser are determined by the doping ion type of the micro / nano crystal. The determination principle is that each pulse excitation laser is absorbed by at least one type of doping ion in the micro / nano crystal, and each type of doping ion in the micro / nano crystal absorbs at least one wavelength of pulse excitation laser. A continuous laser beam is emitted onto the micro / nano crystal to capture a single micro / nano crystal. By controlling the timing of the excitation sequence and time interval of each pulse of excitation laser emitted onto the micro / nano crystal, the order in which different fluorescence appears under the excitation of each pulse of excitation laser is obtained. The order in which different fluorescence appears reflects the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

2. The method for controlling the luminescence of micro / nano crystals with multi-wavelength excitation according to claim 1, characterized in that, The micro / nano crystal is a micro / nano crystal doped with rare earth Yb-Er ions.

3. The method for controlling the luminescence of micro / nano crystals with multi-wavelength excitation according to claim 2, characterized in that, The continuous laser used is a laser with a wavelength of 1342 nm.

4. The method for controlling the luminescence of micro / nano crystals with multi-wavelength excitation according to claim 3, characterized in that, The pulsed excitation laser includes an 808 nm pulsed laser. When the micro / nano crystal is excited by the 808 nm pulsed laser, Er ions absorb the 808 nm light and obtain different fluorescence appearance times. The different fluorescence appearance times reflect the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

5. The method for controlling the luminescence of micro / nano crystals with multi-wavelength excitation according to claim 2, characterized in that, The pulsed excitation laser includes a 976 nm pulsed laser. When the micro / nano crystal is excited by the 976 nm pulsed laser, both Er ions and Yb ions absorb the 976 nm light, resulting in different sequences of fluorescence appearance. The sequence of fluorescence appearance reflects the different population processes of electrons inside the micro / nano crystal and the accumulation of electrons at different energy levels.

6. A device for controlling the luminescence of micro / nano crystals through multi-wavelength excitation, characterized in that, include: The sample chamber is used to hold micro / nano crystals. A continuous laser emission optical path is used to emit a continuous laser beam to the micro / nano crystal to capture a single micro / nano crystal. The wavelength of the continuous laser beam used to capture the single micro / nano crystal is determined according to the absorption spectrum of the micro / nano crystal. The principle for determining the wavelength of the continuous laser beam is that the micro / nano crystal does not absorb the continuous laser beam of that wavelength. The pulsed laser emission and control optical path is used to obtain the temporal order of different fluorescence appearances under the excitation of each pulsed excitation laser on the micro / nano crystal by timing control of the excitation sequence and time interval of each pulsed excitation laser. The wavelength of each pulsed excitation laser corresponding to the absorption spectrum of each type of dopant ion is determined according to the dopant ion type of the micro / nano crystal. The number of pulsed excitation lasers and the wavelength of each pulsed excitation laser are determined by the dopant ion type of the micro / nano crystal. The determination principle is that each pulsed excitation laser is absorbed by at least one type of dopant ion in the micro / nano crystal, and each type of dopant ion in the micro / nano crystal absorbs at least one wavelength of pulsed excitation laser.

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