CN112733375B - Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect - Google Patents

Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect Download PDF

Info

Publication number
CN112733375B
CN112733375B CN202110056317.7A CN202110056317A CN112733375B CN 112733375 B CN112733375 B CN 112733375B CN 202110056317 A CN202110056317 A CN 202110056317A CN 112733375 B CN112733375 B CN 112733375B
Authority
CN
China
Prior art keywords
wavelength
electric field
time domain
film element
thin film
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110056317.7A
Other languages
Chinese (zh)
Other versions
CN112733375A (en
Inventor
王胭脂
张宇晖
贺洪波
陈瑞溢
王志皓
朱晔新
许贝贝
晋云霞
邵宇川
易葵
邵建达
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Institute of Optics and Fine Mechanics of CAS
Original Assignee
Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Institute of Optics and Fine Mechanics of CAS filed Critical Shanghai Institute of Optics and Fine Mechanics of CAS
Priority to CN202110056317.7A priority Critical patent/CN112733375B/en
Publication of CN112733375A publication Critical patent/CN112733375A/en
Application granted granted Critical
Publication of CN112733375B publication Critical patent/CN112733375B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Evolutionary Computation (AREA)
  • Geometry (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Lasers (AREA)

Abstract

A thin film element time domain dynamic electric field simulation method based on a multi-wavelength effect comprises the following steps: and calculating a time domain dynamic electric field of a single wavelength, testing the actually incident laser pulse width and spectrum, and superposing the time domain electric field of each frequency component on the wavelength domain. The method can make up the defects of electric field calculation of the traditional film system design software, accurately obtain the actual electric field distribution of the film element under the action of the ultrashort laser pulse, and provide an effective analysis model for the subsequent design of the film element with high damage resistance.

Description

Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect
Technical Field
The invention belongs to the field of ultrafast laser films, and particularly relates to a method for simulating a time domain dynamic electric field of a thin film element based on a multi-wavelength effect.
Background
The thin film element is an important component in an ultrashort pulse laser system, and the research on the damage behavior of the thin film element under the action of ultrashort pulses is very important. The propagation speed of light is extremely high, the propagation speed in vacuum is 300nm/fs, the propagation speed in a thin film element is generally in the order of femtosecond, and the specific propagation time is related to a film structure and a thin film material. For nanosecond and picosecond lasers, the pulse width is much larger than the propagation time of light between film layers, so even if the laser is pulsed light, the energy input can be approximately considered to be steady state, and when the incident laser is femtosecond laser, the pulse width can be smaller than the propagation time, so that the electric field inside the film layer is constantly changed along with time, namely dynamically distributed. Further, as the pulse width is narrower, the corresponding spectral width is wider, the electric field of each frequency component is different, and the propagation velocity is also different, so that the actual electric field distribution needs to take into account the multi-wavelength effect.
At present, traditional film system design software (TFCalc, Macleod, Optilayer and the like) analyzes and calculates a single-wavelength steady-state electric field of a film layer, so that the electric field calculation result of a thin film element under the action of an ultrashort pulse is limited.
Disclosure of Invention
The invention aims to solve the problems and designs a thin film element time domain dynamic electric field simulation method based on a multi-wavelength effect through multi-physical field coupling software COMSOL.
The technical scheme adopted by the invention for solving the technical problems is as follows:
1) according to the film thickness of the film element, the film material and the optical constant of the material, establishing a film element entity model in the multi-physical-field coupling software COMSOL, and carrying out mesh generation on an input geometric body, wherein the mesh generation comprises the steps of selecting a unit type, setting the mesh size and testing the mesh accuracy;
2) selecting electromagnetic waves (transient state) as a calculation physical field, and setting boundary conditions, wherein the boundary (close to an incident medium) of the outermost layer and the boundary (close to a substrate) of the innermost layer of the thin film adopt scattering boundary conditions, and the two side edges of the thin film element mirror adopt periodic boundary conditions;
3) and loading a Gaussian pulse beam on the boundary of the outermost layer. The beam propagates in the x-direction, with a transverse gaussian intensity in the y-direction and an out-of-plane z-direction for the polarization of the electric field. The time-harmonic Maxwell equation solution of the two-dimensional geometry can be approximated by an analytic solution of the following paraxial wave equation:
Figure BDA0002900991790000021
Figure BDA0002900991790000022
Figure BDA0002900991790000023
Figure BDA0002900991790000024
wherein DEFI (λ)iR, t) is the time domain dynamic electric field at a single wavelength, λiFor a corresponding single wavelength, r is the depth coordinate of the thin film element, t is time, E0Is the peak of the electric field, w0Is the minimum girdling, x0For the Rayleigh range, w is the angular frequency, y is the in-plane abscissa, k is the wave number, t0For pulse delay time, dt is the pulse width and η (x) is the Gouy phase shift. The wavefront shape of the beam is not completely planar; the propagation of the wave is similar to a spherical wave with the radius R (x), and the time domain dynamic electric field DEFI (lambda) of the thin film element at each depth of the single wavelength, which is continuously changed along with the time, is obtainediR, t) and the dwell time t of the pulsed light inside the films；
4) Testing the actual incident laser pulse width dt and the spectrum to obtain the intensity factor I (lambda) of the incident laser in each wave band;
5) calculating the time domain dynamic electric field distribution under all single wavelengths in the actual spectral range of the incident laser
DEFI(λ1,r,t)、DEFI(λ2,r,t)、DEFI(λ3R, t) … …. In order to ensure the calculation precision, the wavelength interval is not more than 5% of the difference value between the maximum wavelength and the minimum wavelength;
6) multiplying all the obtained single-wavelength electric fields by the intensity factors under the wavelength, adding, and dividing by the sum of the intensity factors to obtain a multi-wavelength time domain dynamic electric field DEFI (r, t) of the thin film element, wherein the calculation formula is shown as the following formula:
Figure BDA0002900991790000025
compared with the prior art, the invention has the following technical effects:
1) a wavelength domain. Considering that the transmission speeds of different wavelength components are different, and the electric fields formed by the different wavelength components are different, the obtained result is closer to the actual electric field distribution, and the damage threshold and the damage part of the thin film element can be judged in advance from the electric field distribution;
2) the time domain. The final electric field calculation result is dynamically distributed along with time, and the forming time of the electric field extreme value, namely the damage moment of the thin film element, can be obtained.
Drawings
FIG. 1 is a flow chart of a simulation method according to the present invention.
FIG. 2 shows the electric field distribution at the 800nm center wavelength obtained by conventional film system design software.
Fig. 3 is a laser spectrum during actual testing.
FIG. 4 is a time domain dynamic electric field distribution at multiple wavelengths.
Detailed Description
The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings, but should not be construed to limit the scope of the present invention.
FIG. 1 is a flow chart of a thin film device time domain dynamic electric field simulation method based on multi-wavelength effect according to the present invention.
Example 1: the thin film element is a chirped mirror with a bandwidth of 700-900nm and a dispersion of-150 fs2And the reflectivity is more than 99.5% at an incident angle of 5 degrees.
The detailed steps are as follows:
1) according to the film thickness of the film element, the film material and the optical constant of the material, the refractive index of the material is shown in the following table, a film element entity model is established in the multi-physical-field coupling software COMSOL, and the mesh subdivision is carried out on the input geometric solid, wherein the mesh subdivision comprises the steps of selecting the cell type, setting the mesh size and testing the mesh precision;
A0 A1 A2
SiO2 1.44293 1.16226181e-2 -3.70553295e-4
Nb2O5 2.15786 3.61226445e-2 2.024012e-3
2) selecting electromagnetic waves (transient state) as a calculation physical field, and setting boundary conditions, wherein the boundary (close to an incident medium) of the outermost layer and the boundary (close to a substrate) of the innermost layer of the thin film adopt scattering boundary conditions, and the two side edges of the thin film element mirror adopt periodic boundary conditions;
3) and loading a Gaussian pulse beam on the boundary of the outermost layer. The beam propagates in the x-direction, with a transverse gaussian intensity in the y-direction and an out-of-plane z-direction for the polarization of the electric field. The time-harmonic Maxwell equation solution of the two-dimensional geometry can be approximated by an analytic solution of the following paraxial wave equation:
Figure BDA0002900991790000041
Figure BDA0002900991790000042
Figure BDA0002900991790000043
Figure BDA0002900991790000044
5) wherein DEFI (λ)iR, t) is a single wavelength time domain dynamic electric field, E0Is the peak of the electric field, w0Is the minimum girdling, x0For the Rayleigh range, w is the angular frequency, y is the in-plane abscissa, k is the wave number, t0For pulse delay time, dt is the pulse width and η (x) is the Gouy phase shift. The wavefront shape of the beam is not completely planar; the propagation of the wave is similar to a spherical wave with the radius R (x), and the time domain dynamic electric field DEFI (lambda) of the thin film element at each depth of the single wavelength, which is continuously changed along with the time, is obtainediR, t) and the dwell time t of the pulsed light inside the films；
The parameters used in the calculation are shown in the following table:
name (R) Expression formula Value of Description of the invention
w0 2μm 2E-6m Minimum spot radius of laser beam
Lambda0 800nm 0.8E-6m Incident laser wavelength
E0 6KV/m 6000V/m Peak value of electric field
x0 pi*w0^2/lambda 1.5635E-5m Rayleigh range
k0 2*pi/lambda 7.85E6 1/m Propagation constant
w k0*c_const 2.35E15 1/s Angular frequency
t0 60fs 6E-14s Pulse delay time
dt 30fs 3E-14s Pulse width
4) Testing the actually incident laser pulse width dt spectrum to obtain the intensity factor I (lambda) of the incident laser in each waveband, wherein the actually incident spectrum is shown in FIG. 3, the energy distribution is 750-850 nm, the pulse width is 30fs, and the dwell time ts of the pulsed light in the film is 450 fs;
5) calculating the time-domain dynamic electric field distribution DEFI (lambda) at all single wavelengths in the actual spectral range of the incident laser light1,r,t)、DEFI(λ2,r,t)、DEFI(λ3R, t) … …. In order to ensure the calculation precision, the wavelength interval is 5 nm;
6) multiplying all the obtained single-wavelength electric fields by the intensity factors under the wavelength, adding, and dividing by the sum of the intensity factors to obtain a multi-wavelength time domain dynamic electric field DEFI (r, t) of the thin film element, wherein the calculation formula is shown as the following formula:
Figure BDA0002900991790000051
it can be seen that the conventional electric field peak is located inside the film layer, but actually, because the propagation speeds of different frequency components are different, a time difference exists when the peak is formed inside the film layer, so that the electric field inside the film layer is reduced, and the accurate electric field peak is located on the surface of the film layer, so for the dispersion mirror, the initial damage part is located on the front film layer, and the actual damage test result is consistent with the model calculation result.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (2)

1. A thin film element time domain dynamic electric field simulation method based on multi-wavelength effect is characterized in that: the electric field obtained by the method dynamically changes along with time, and the superposition calculation is carried out on a wavelength domain by considering the multi-wavelength effect under a wide spectrum and combining the intensity distribution of an actual spectrum, wherein the method comprises the following steps:
1) calculating the time domain dynamic electric field distribution under the single wavelength by the COMSOL software to obtain the time domain dynamic electric field DEFI (lambda) of the thin film element under the single wavelength which changes constantly with time at each depthiR, t) and the dwell time t of the pulsed light inside the filmsWherein λ isiIs the corresponding single wavelength, r is the depth coordinate of the thin film element, and t is the time;
2) testing the pulse width dt and the spectrum of the actually incident laser to obtain the intensity factor I (lambda) of the incident laser in each wave bandi )；
3) Calculating the time domain dynamic electric field distribution DEFI (lambda) at all single wavelengths in the actual spectral range of the incident laser1,r,t)、DEFI(λ2,r,t)、DEFI(λ3R, t) … …; in order to ensure the calculation precision, the wavelength interval is not more than 5% of the difference value between the maximum wavelength and the minimum wavelength;
4) multiplying all the obtained single-wavelength electric fields by the intensity factors under the wavelength, adding, and dividing by the sum of the intensity factors to obtain a multi-wavelength time domain dynamic electric field DEFI (r, t) of the thin film element, wherein the calculation formula is shown as the following formula:
Figure FDA0002900991780000011
2. the method for simulating the time domain dynamic electric field of the thin film element under the multi-wavelength effect according to claim 1, wherein: the retention time t of the pulsed light in the film layer in the step 1sIt is greater than the pulse width dt described in step 2.
CN202110056317.7A 2021-01-15 2021-01-15 Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect Active CN112733375B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110056317.7A CN112733375B (en) 2021-01-15 2021-01-15 Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110056317.7A CN112733375B (en) 2021-01-15 2021-01-15 Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect

Publications (2)

Publication Number Publication Date
CN112733375A CN112733375A (en) 2021-04-30
CN112733375B true CN112733375B (en) 2022-05-31

Family

ID=75591703

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110056317.7A Active CN112733375B (en) 2021-01-15 2021-01-15 Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect

Country Status (1)

Country Link
CN (1) CN112733375B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW201224434A (en) * 2010-12-06 2012-06-16 Univ Nat Central Multi-wavelength optical measurement method for thin film device
CN105932533A (en) * 2016-07-13 2016-09-07 中国人民解放军国防科学技术大学 Multi-wavelength mid-infrared optical parametric oscillator based on self-Raman effect of crystal
WO2019095490A1 (en) * 2017-11-15 2019-05-23 西南交通大学 Radio-over-fiber communication beamforming device and method using arrayed waveguide optical grating

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012038805A (en) * 2010-08-04 2012-02-23 Precise Gauges Co Ltd Detector for detecting electric field distribution or carrier distribution based on intensity of higher order harmonic

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW201224434A (en) * 2010-12-06 2012-06-16 Univ Nat Central Multi-wavelength optical measurement method for thin film device
CN105932533A (en) * 2016-07-13 2016-09-07 中国人民解放军国防科学技术大学 Multi-wavelength mid-infrared optical parametric oscillator based on self-Raman effect of crystal
WO2019095490A1 (en) * 2017-11-15 2019-05-23 西南交通大学 Radio-over-fiber communication beamforming device and method using arrayed waveguide optical grating

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
多波长飞秒激光损伤可见光滤光片的实验及机理;朱志武等;《红外与毫米波学报》;20120815(第04期);全文 *

Also Published As

Publication number Publication date
CN112733375A (en) 2021-04-30

Similar Documents

Publication Publication Date Title
CN110640338B (en) Composite pulse laser deep hole processing device based on Bessel light beam
US20160271727A1 (en) Method and device for laser micromachining
CN110125536A (en) A kind of laser processing device and method of thin-film material removal
CN108873322B (en) Method and system for determining curved surface structure of long-focal-depth aspheric reflector
Wang et al. Simulation of femtosecond laser ablation sapphire based on free electron density
CN101615754B (en) Method and device for dynamic compensation and pulse compression of higher harmonics intrinsic chirp
Singh et al. Excimer laser micromachining of indium tin oxide for fabrication of optically transparent metamaterial absorbers
Alexeev et al. Application of Bessel beams for ultrafast laser volume structuring of non transparent media
CN112733375B (en) Thin film element time domain dynamic electric field simulation method based on multi-wavelength effect
Römer et al. Finite-difference time-domain modeling of laser-induced periodic surface structures
CN103928833B (en) A kind of pulse train manipulator based on plated film
Zayarny et al. Nonlinear absorption mechanisms during femtosecond laser surface ablation of silica glass
Heins et al. Shock-induced concentric rings in femtosecond laser ablation of glass
CN112334420A (en) Method for laser processing a substrate stack with one or more transparent workpieces and a black matrix layer
Yang et al. Model development for nanosecond laser-induced damage caused by manufacturing-induced defects on potassium dihydrogen phosphate crystals
CN110927125B (en) Method for setting damage threshold of femtosecond high-power laser to transparent material
Coyne et al. Characterisation of laser ablation of silicon using a Gaussian wavefront and computer generated wavefront reconstruction
CN113946005A (en) Broadband high-laser damage threshold dispersion mirror structure
CN112756777A (en) Laser blackening treatment method for metal surface
Li et al. Experimental investigation and optimization of modification during coaxial waterjet-assisted femtosecond laser drilling
CN101650469B (en) Femtosecond single and double-pulse converting device
Yang et al. Characterization of the transient thermal-lens effect using top-hat beam Z-scan
Yang et al. Detection and simulation of defects on precision optical surface
Tan et al. Repaired morphology of CO2 laser rapid ablation mitigation of fused silica and its influence on downstream light modulation
Orlov et al. Propagation of vector nondiffracting and nondispersive pulsed beams through an air-dielectric planar interface

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant