Particle Scattering Simulator

ESM: three.js + fft.js

Controls

Image size (pow2 for FFT) [px]: 256

Pixel size [μm]: 0.30

Wavelength $\lambda$ [nm]: 550

NA: 0.80

Imaging mode

PC: plate radius [% pupil]

PC: phase shift [rad]: 1.57

PC: attenuation α: 0.60

DF: inner NA fraction: 0.25

Δn = n_p − n₀: 0.1

κ (absorption): 0.001

Coherent source intensity: 0.5

Fluorescence intensity: 5.00

Focal defocus $z$ [μm]: 0.00

Scatterers: 10

Radius [μm]: 0.50

Depth $z$ std $\sigma_z$ [μm]: 1.00

fBm Hurst $H$ [–]: 0.50

Viscosity $\eta$ [Pa·s]: 1.00e-3

Sim $\Delta t$ [ms]: 20

Max FPS [Hz]: 20

Scale bar [μm]:

Verbose (show checks)

Model: image field $U=\mathcal{F}^{-1}\!\{\, P(\mathbf{f})\,e^{i\pi\, \lambda\, z\, |\mathbf{f}|^2}\, \mathcal{F}\{T(\mathbf{x})\} \}\,$, intensity $I=|U|^2$. Pupil cutoff $f_c=\mathrm{NA}/\lambda$. Particles has depths $z_i \sim \mathcal{N}(0,\sigma_z^2)$. Motion: 3D fBm with step $\propto \eta^{-1/2}\,\Delta t^{H}$.

Key libraries used: three.js from unpkg.com, fft.js from esh.sh

Navigation tips

Scroll the mouse wheel to change the focal plane z (Shift = faster)).
Press spacebar or Pause/Play button to halt microscopy view (simulated Brownian motion continues).
Switch imaging modes to see how contrast differs.