CN-122016574-A - Nanometer bubble optical coefficient measurement method based on multilayer spherical shell Mie theory

CN122016574ACN 122016574 ACN122016574 ACN 122016574ACN-122016574-A

Abstract

The application discloses a measuring method of nanometer bubble optical coefficient based on multi-layer spherical shell Mie theory, relating to the technical field of nanometer bubble and nanometer particle optical property measurement, aiming at the problem that the prior method can not measure the optical property of nanometer bubble, the application obtains the energy of nanometer particle for absorbing laser according to the change of nanometer particle transmission light intensity, and (3) bringing the nano bubble into an energy equation, obtaining the temperature and the density of the nano bubble forming process by a lattice Boltzmann method, and further obtaining the optical coefficient of the nano particle wrapped by the nano bubble based on a multi-layer spherical shell Mie theory according to the change condition of the refractive index field with the degree.

Inventors

JI YUKUN
REN YATAO
QI HONG

Assignees

哈尔滨工业大学

Dates

Publication Date: 20260512
Application Date: 20260212

Claims (10)

1. The measuring method is characterized in that the measuring method is realized based on a measuring device, the measuring device comprises a pulse laser, a detection laser, an objective lens, a first photoelectric detector and a second photoelectric detector, high-energy pulse laser emitted by the pulse laser irradiates nanoparticles in an aqueous solution after being focused by the objective lens, and continuous laser with low energy emitted by the detection laser irradiates the nanoparticles at the same time, and the first photoelectric detector and the second photoelectric detector are used for respectively acquiring laser intensity after the pulse laser and the detection laser irradiate the nanoparticles; The measuring method specifically comprises the following steps: Step one, a detection laser is turned on, so that continuous laser emitted by the detection laser irradiates the nano-particles, and meanwhile, laser power of the detection laser after irradiating the nano-particles is obtained through a second photoelectric detector; step two, a pulse laser is turned on, after the pulse laser is fully preheated, the output power of the pulse laser and the position of the pulse laser are adjusted until the signal of a second photoelectric detector changes, and at the moment, the laser emitted by the pulse laser irradiates on the nano particles; recording the output power of the pulse laser, namely the incident laser power, and turning on a first photoelectric detector to record the transmitted laser power after the laser irradiates the nano particles; Subtracting the transmitted laser power from the incident laser power to obtain the laser power absorbed by the nano particles on the incident laser ; Step five, acquiring the volume of the nano particles and utilizing laser power Dividing the volume of the nano particles to obtain the volume heat source density of the nano particles ; Step six, the volume heat source density of the nano particles Bringing into an energy equation to obtain temperature space distribution And according to the nanoparticle and temperature spatial distribution Obtaining the fluid density by using a lattice Boltzmann method; and seventhly, obtaining the refractive index spatial distribution of the fluid by an interpolation method based on the spatial distribution of the fluid density, and obtaining the transient optical coefficient of the nano particles in the nano bubble forming process by utilizing the multi-layer spherical shell Mie theory based on the refractive index spatial distribution of the fluid.
2. The method for measuring optical coefficient of nanometer bubble based on the Mie theory of a multi-layer spherical shell according to claim 1, wherein the optical coefficient in the seventh step comprises absorption Scattering of And extinction coefficient Expressed as: ; ; ; Wherein, the , , The refractive index of the outermost cut-off of the spherical shell, Is the radius of the spherical shell at the outermost layer, Is the wavelength of the incident wave in the vacuum, And In order to be a scattering coefficient, As an intermediate variable, the number of the variables, Is constant.
3. The method for measuring the optical coefficient of the nano bubble based on the multi-layer spherical shell Mie theory according to claim 2, wherein the scattering coefficient is characterized by Expressed as: ; Scattering coefficient Expressed as: ; ; ; ; ; ; ; ; Wherein, the To handle the intermediate amount of the TM wave recursion, To handle the intermediate amount of TE wave recursion, The total number of relative refractive indices is divided for the spherical shell, 、、 And For the Riccati-Bessel function, , The total number of the spherical shells is divided, And Is the logarithmic derivative of the Riccati-Bessel function, Is the first The relative refractive index of the spherical shell of the individual, Is the first The relative refractive index of the spherical shell of the individual, Is the first The dimensional parameters of the spherical shell of each, Is the first The dimensional parameters of the spherical shell of each, 、、 And Is an intermediate variable.
4. The method for measuring the optical coefficient of the nano bubble based on the multi-layer spherical shell Mie theory according to claim 3, wherein the step six is specifically as follows: Step six, the volume heat source density of the nano particles Carrying out an energy equation, and solving by using a finite difference method to obtain the temperature of the nano particles And fluid temperature And utilizes the temperature of the nanoparticles And fluid temperature Constructing a temperature spatial distribution ; Step six, obtaining fluid speed and fluid density according to intermolecular acting force and a distribution function in the lattice Boltzmann method; Step six, judging whether the maximum iteration number is reached, if the maximum iteration number is reached, executing step six, and if the maximum iteration number is not reached, executing step six; Outputting the obtained fluid density; step six five, based on temperature space distribution And obtaining the fluid pressure by using the P-R state equation, taking the fluid pressure and the fluid speed as the fluid pressure and the fluid speed in the energy equation and the distribution function respectively, and repeating the steps from six one to six three.
5. The method for measuring the optical coefficient of the nano bubble based on the multi-layer spherical shell Mie theory according to claim 4, wherein the energy equation is expressed as follows: ; ; Wherein, the 、、 Respectively the density, the heat conductivity coefficient and the specific heat capacity of the fluid, For time, subscript Is noble metal material, subscript Is in the form of an aqueous solution, In the case of a fluid pressure, Is the fluid velocity.
6. The method for measuring the optical coefficient of the nano bubble based on the multi-layer spherical shell Mie theory according to claim 5, wherein the distribution function is expressed as: ; ; Wherein, the As a vector of the position of the object, For the time step size of the time step, Is a matrix of units which is a matrix of units, In the form of a discrete force item, As a source item, a source item is provided, In the form of a diagonal matrix of relaxation parameters, 、、、 Are all a function of the distribution, As a function of the distribution of the equilibrium state, Is a discrete velocity.
7. The method for measuring the optical coefficient of the nano bubble based on the multi-layer spherical shell Mie theory according to claim 6, wherein the source term is characterized in that Expressed as: ; ; ; ; ; ; ; Wherein, the 、、、、、 Is that Is used for the control of the degree of freedom of the composition, Is the speed of sound of the lattice, And As the coefficient of the light-emitting diode, As the coefficient of intermolecular forces of force, As a function of the pseudo-potential, As the force between the molecules of the fluid, 、、 Respectively is Along with 、、 Components of the axis in three directions.
8. The method for measuring the optical coefficient of the nano bubble based on the multi-layer spherical shell Mie theory according to claim 7, wherein the discrete force term Expressed as: ; Wherein, the 、、 Along the velocity of the fluid 、、 Components of the axis in three directions.
9. The method for measuring the optical coefficient of the nano bubble based on the Mie theory of the multilayer spherical shell according to claim 8, wherein the acting force between the fluid molecules is characterized in that Expressed as: ; ; ; Wherein, the As the weight coefficient of the light-emitting diode, Is an intermediate variable.
10. The method for measuring the optical coefficient of the nano bubble based on the multi-layer spherical shell Mie theory according to claim 9, wherein the fluid velocity is as follows Expressed as: ; ; Wherein, the Is a distribution function; the fluid pressure Expressed as: ; Wherein, the Is a gas constant which is a general purpose gas constant, And Is constant.

Description

Nanometer bubble optical coefficient measurement method based on multilayer spherical shell Mie theory Technical Field The application relates to the technical field of nano bubble and nano particle optical property measurement, in particular to a nano bubble optical coefficient measurement method based on a multi-layer spherical shell Mie theory. Background The plasma nanometer bubble is generated based on the light excitation of noble metal nanometer particles, and the special light-heat conversion efficiency and the adjustable optical characteristics of the plasma nanometer bubble draw attention. The technology has been widely used in the fields of biosensing, tissue imaging, targeted gene and drug delivery, disease treatment, material synthesis, and the like. Notably, when the nanostructure is irradiated by laser light at its localized surface plasmon resonance wavelength, the fluid medium undergoes a phase change due to localized overheating, thereby forming nanobubbles. The nano bubbles show important application potential in the multidisciplinary field by virtue of controllable nonlinear optical characteristics, excellent photo-thermal properties and remarkable mechanical effects. For example, in the biomedical field, its light scattering properties make it particularly useful for disease imaging and diagnostic applications. Accordingly, related scholars have devoted much research to elucidate the basic mechanism of plasma nanobubble formation and to explore the transient optical properties of nanoparticles encapsulated by nanobubbles. However, the current nano bubble detection methods, such as dark field microscope, acoustic detection, optical transmission measurement, and the like, can only obtain the size of the nano bubbles, and cannot measure the optical properties of the nano bubbles. Disclosure of Invention The invention aims to provide a method for measuring the optical coefficient of a nano bubble based on a multi-layer spherical shell Mie theory, aiming at the problem that the optical property of the nano bubble cannot be measured by the existing method. The technical scheme adopted by the invention for solving the technical problems is as follows: The measuring method is realized based on a measuring device, the measuring device comprises a pulse laser, a detection laser, an objective lens, a first photoelectric detector and a second photoelectric detector, high-energy pulse laser emitted by the pulse laser irradiates nanoparticles in an aqueous solution after being focused by the objective lens, and continuous laser emitted by the detection laser with low energy irradiates the nanoparticles at the same time, wherein the first photoelectric detector and the second photoelectric detector are used for respectively acquiring the laser intensity of the pulse laser and the laser intensity of the laser emitted by the detection laser after the nanoparticles are irradiated; The measuring method specifically comprises the following steps: Step one, a detection laser is turned on, so that continuous laser emitted by the detection laser irradiates the nano-particles, and meanwhile, laser power of the detection laser after irradiating the nano-particles is obtained through a second photoelectric detector; step two, a pulse laser is turned on, after the pulse laser is fully preheated, the output power of the pulse laser and the position of the pulse laser are adjusted until the signal of a second photoelectric detector changes, and at the moment, the laser emitted by the pulse laser irradiates on the nano particles; recording the output power of the pulse laser, namely the incident laser power, and turning on a first photoelectric detector to record the transmitted laser power after the laser irradiates the nano particles; Subtracting the transmitted laser power from the incident laser power to obtain the laser power absorbed by the nano particles on the incident laser ; Step five, acquiring the volume of the nano particles and utilizing laser powerDividing the volume of the nano particles to obtain the volume heat source density of the nano particles; Step six, the volume heat source density of the nano particlesBringing into an energy equation to obtain temperature space distributionAnd according to the nanoparticle and temperature spatial distributionObtaining the fluid density by using a lattice Boltzmann method; and seventhly, obtaining the refractive index spatial distribution of the fluid by an interpolation method based on the spatial distribution of the fluid density, and obtaining the transient optical coefficient of the nano particles in the nano bubble forming process by utilizing the multi-layer spherical shell Mie theory based on the refractive index spatial distribution of the fluid. Further, the optical coefficient in the seventh step includes absorptionScattering ofAnd extinction coefficientExpressed as: ; ; ; Wherein, the ,,The refractive index of the outermost cut-off of the spheric