Data from: Acoustic wave modulation of gap plasmon cavities
Data files
Jul 31, 2025 version files 6.30 GB
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Data_for_Fig_1.zip
986.05 MB
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Data_for_Fig_2.zip
55.45 MB
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Data_for_Fig_3.zip
2.45 GB
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Data_for_Fig_4.zip
873.64 MB
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movie_S1_uncut.avi
1.94 GB
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README.md
9.76 KB
Abstract
The important role of metallic nanostructures in nanophotonics will expand if ways to electrically manipulate their optical resonances at high speed can be identified. We capitalized on electrically driven surface acoustic waves and the extreme light concentration afforded by gap plasmons to achieve this goal. We placed gold nanoparticles in a particle-on-mirror configuration with a few-nanometer-thick, compressible polymer spacer. Surface acoustic waves were then used to tune light scattering at speeds approaching the gigahertz regime. We observed evidence that the surface acoustic waves produced mechanical deformations in the polymer and that ensuing nonlinear mechanical dynamics led to unexpectedly large levels of strain and spectral tuning. Our approach provides a design strategy for electrically driven dynamic metasurfaces and fundamental explorations of high-frequency, polymer dynamics in ultraconfi ned geometries.
Corresponding manuscript: “Acoustic Wave Modulation of Gap Plasmon Cavities,” submitted to Science.
This repository contains all data, code, and simulation files required to reproduce the figures in the manuscript.
Software versions: MATLAB R2023a, COMSOL Multiphysics 5.6.
Units: SI unless otherwise noted.
File and folder names appear in monospace.
Data_for_Fig_1.zip
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Matlab_sigma_sc_plotting.m
MATLAB script that plots the scattering cross section versus gap size and wavelength. -
NPoMsym15_lam_solve_5.3E-7_gap_4E-9_theta_0_facet_size_4E-8.mph
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NPoMsym15_lam_solve_6.7E-7_gap_4E-9_theta_0_facet_size_4E-8.mph
COMSOL 5.6 optical frequency‑domain simulations of the NPoM structure at normal incidence. Each file contains the full solution for a single wavelength, gap size, and facet size (all encoded in the filename). -
NPoMsym15_lam_solve_5p3Em7_gap_4Em9_theta_0_facet_size_4Em8.java
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NPoMsym15_lam_solve_5p3Em7_gap_4Em9_theta_0_facet_size_4Em8.m
Java and MATLAB model files ofNPoMsym15_lam_solve_5.3E-7_gap_4E-9_theta_0_facet_size_4E-8.mph
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NPoMsym15_lam_solve_6p7Em7_gap_4Em9_theta_0_facet_size_4Em8.java
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NPoMsym15_lam_solve_6p7Em7_gap_4Em9_theta_0_facet_size_4Em8.m
Java and MATLAB model files ofNPoMsym15_lam_solve_6.7E-7_gap_4E-9_theta_0_facet_size_4E-8.mph
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sigma_sc_TM__ALL.txt
Numerical optical results for 700 simulations.
Column Description 1 Free‑space wavelength (m) 2 Gap size (m) 3 (unused; all zeros) 4 Facet size (m) — constant 40 nm 5 (unused; all zeros) 6 Scattering cross-section (m²)
Data_for_Fig_2.zip
2D SAW - dispersion with full metal covering.mph
COMSOL eigenfrequency simulation of the Y-Z LiNbO₃ surface-acoustic-wave (SAW) mode with full metal coverage (Fig. 2B).twoD_SAW_dispersion_with_full_metal_covering.java
twoD_SAW_dispersion_with_full_metal_covering.m
Java and MATLAB model files of2D SAW - dispersion with full metal covering.mph
ChirpIDT_PML_230519.mph
COMSOL electro‑mechanical frequency‑domain simulation of the complete device, including the interdigitated transducer (IDT) and metal films.ChirpIDT_PML_230519.java
ChirpIDT_PML_230519.m
Java and MATLAB model files ofChirpIDT_PML_230519.mph
.ChirpedIDT_PML_AllProbeData_230519.txt
Surface-displacement probe data exported from the file above.
Column 7 gives the out‑of‑plane displacement at a point adjacent to the IDT, corresponding to the region probed optically (plotted as the Simulation trace in Fig. 2C).SAW_IDT_transducers_acoustic_sim_plotting_230519.m
MATLAB script that imports experimental surface‑displacement measurements, compares them with the simulated displacements in
ChirpedIDT_PML_AllProbeData_230519.txt
, and generates Fig. 2C.
Data_for_Fig_3.zip
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Time_resolved_spectra_and_peak_plasmon_resonance_V2.m
MATLAB script that plots the time-resolved spectra for the SOR and FOR modes. -
Gap_size_projections_250220.m
Converts the plasmon‑resonance wavelength (λ₁₁) to instantaneous gap size using a COMSOL mapping similar to Fig. 1D. -
time_and_peaks_of_NP133_231106_chop2500.mat
Contains time‑vs‑peak plasmon‑resonance wavelength (λ₁₁) data produced by the time‑resolved spectra plotting script for the SOR. -
time_and_peaks_of_NP133_231106_TCSPC.mat
Contains time‑vs‑peak plasmon‑resonance wavelength (λ₁₁) data produced by the time‑resolved spectra plotting script for the FOR. -
Matlab_spectrum_plotting_RFoff_vs_RFon_231206.m
Plots the time‑averaged spectrum (Fig. 3D). -
sigma_sc_TE__ALL.txt
Numerical optical results for 1,488 simulations.Column Description 1 Free‑space wavelength (m) 2 Gap size (m) 3 (unused; all zeros) 4 Refractive index of gap filler 5 (unused; all zeros) 6 Scattering cross‑section (m²) -
Picoharp T2 data 231106/*.txt
Raw time‑correlated single‑photon counting (TCSPC) data acquired in T2/TTTR mode (SOR). Each file is a text file with four columns. Each row represents the detection of a single sync event or photon. Channel 0 is the sync channel synchronized with the RF power chopping signal. Channel 1 is connected to a single‑photon avalanche detector that detects photons from a single NPoM. Filename parameters: sample name = LNw21s16; NPoM name = NP133; SAW frequency = 670 MHz; SAW power‑chopping frequency = 2,500 Hz; optical illumination wavelength = 500 to 700 with 10nm step size.Column Description 1 Event number 2 (unused; reads “CHN”) 3 Channel number 4 Time at which the event occurred (ps) -
Picoharp T2 data 231106/T2_matlab_analysis_flexable.m
Wraps raw time‑correlated T2 photon events around the sync signals, generating the periodic optical signal, and exportsNP133_SAWfreq_670MHz_chop2500Hz_cycleDiv5000.mat
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Picoharp T2 data 231106/NP133_SAWfreq_670MHz_chop2500Hz_cycleDiv5000.mat
MATLAB data file for the periodic optical signal of a single NPoM (NP133). The variableall_cnts
contains all 21 wavelengths at which the periodic T2 optical signal was acquired. The 400‑µs period (1/2500 Hz) is divided into 5,000 bins. -
Picoharp TCSPC data 231106/*.mat
Raw TCSPC data for the fast optical response (FOR). Each file is a.mat
file with a single variable namedoutput
that contains time in one column and optical counts in the other. Filename parameters: sample name = LNw21s16; NPoM name = NP133; SAW frequency = 670 MHz; optical illumination wavelength = 500 to 700 with 10nm step size. -
Picoharp TCSPC data 231106/NP133_231106_TCSPC.gif
Animated GIF of the optical scattering spectrum (FOR). -
Picoharp TCSPC data 231106/TCSPC_matlab_analysis_flexable.m
Compiles all raw TCSPC.mat
files into a single data file containing all optical wavelengths and signal amplitudes:NP133_TCSPC_SAWfreq_670.mat
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Picoharp TCSPC data 231106/NP133_TCSPC_SAWfreq_670.mat
Data file containing all optical wavelengths and signal amplitudes from the raw.mat
files. -
spectrum data 231106/
Raw time‑averaged spectra (Fig. 3D) acquired with a grating spectrometer. -
spectrum data 231106/ref75_z0_10s_from_231031 015.csv
Time‑averaged spectrum of the lamp. -
spectrum data 231106/dark_100s_from_231031 014.csv
Time‑averaged dark‑current spectrum. -
spectrum data 231106/NP133_rfoff_100s 009.csv
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spectrum data 231106/NP133_rfoff_100s 011.csv
Time‑averaged spectrum of NP133 with the SAW RF power off (no acoustic wave). -
spectrum data 231106/NP133_670MHz_100s 010.csv
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spectrum data 231106/NP133_670MHz_100s 012.csv
Time‑averaged spectrum of NP133 with the SAW RF power on (acoustic wave active). -
spectrum data 231106/NP133_backgnd_100s 013.csv
Time‑averaged spectrum of the planar gold film adjacent to NP133. This is defined as the background spectrum for NP133. -
spectrum data 231106/NP133_670MHz_expNum_12_bckgnd.mat
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spectrum data 231106/NP133_670MHz_expNum_12_no_bckgnd.mat
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spectrum data 231106/NP133_RFoff_expNum_11_bckgnd.mat
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spectrum data 231106/NP133_RFoff_expNum_11_no_bckgnd.mat
Time‑averaged spectra at the 21 wavelengths at which the time‑resolved spectrum was measured.bckgnd
indicates the spectrum includes the background signal;no_bckgnd
indicates the background has been subtracted.
Data_for_Fig_4.zip
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Full_equn_solve_lin_spr_and_lin_asym_vis_240823.m
MATLAB script that implements both the nonlinear and linear spring–dashpot (with asymmetric drag) models used to generate Fig. 4D. -
Matlab_analysis_oneArea_240823.m
Analysis script used to create Fig. 4E. Dark‑field videos of multiple NPoMs
are processed with a 1 Hz lock‑in technique to extract the SOR amplitude versus SAW frequency or power. -
LNw21s14_freq_sweep_100to800MHz_005_ver2.avi
Video of a frequency sweep from 100 MHz to 800 MHz (linear in time). -
LNw21s14_pow_sweep_550MHz_005_stable.avi
Video of a power sweep from –30 dBm to +3 dBm (linear in time, logarithmic power scale). -
Pchip_vs_PznbdBm_550MHz.mat
Calibration table mapping RF‑source output power to the power delivered to the IDT, compensating for amplifier nonlinearity.Helper functions (required by
Matlab_analysis_oneArea_240823.m
):Pznb_dBm_2_Pchip.m
oneArea_noMask_simulStart_240823.m
readAVI.m
movie_S1_uncut.avi
Full-length, raw (unstabilized) Movie S1 acquired as a fast time-lapse in NIS-Elements AR. The surface acoustic wave is toggled on and off at 1 Hz while its frequency is continuously swept from 100 MHz to 1 GHz over ~350 s. The focus was manually adjusted throughout the recording to compensate for drift.
Contact
For questions, please contact the corresponding authors at
selvin@stanford.edu • brongersma@stanford.edu