Home▸Physics & Mechanics▸The Talbot Effect: Self-Imaging Without a Lens

🪞 The Talbot Effect: Self-Imaging Without a Lens

Explore how coherent light passing through a diffraction grating spontaneously reproduces its own pattern at regular distances downstream, with no lens involved, and discover the fractal-like Talbot carpet hiding in between.

Physics & Mechanics3DModerate60 FPS

The simulator renders the near-field intensity pattern behind a coherent light source passing through a periodic diffraction grating, showing how the grating's image sharpens, blurs, shifts, and doubles in frequency as propagation distance increases, and it builds up the full two-dimensional Talbot carpet in real time.

🔬 What It Demonstrates

🎮 How to Use

Set the grating period and the wavelength of the illuminating light, then scan the propagation distance slider to watch the intensity pattern evolve. Jump directly to the calculated Talbot length to see the sharp self-image reappear, check the half-Talbot-length point to see the shifted repeat, and check the quarter-Talbot-length point to see the frequency-doubled sub-image. Toggle the Talbot carpet view to see the full distance-versus-position map at once.

💡 Did You Know?

The same self-imaging trick that Henry Fox Talbot noticed with sunlight and a grating in 1836 is now used inside modern hospital-grade X-ray scanners, where a Talbot-Lau grating interferometer extracts phase-contrast detail from soft tissue that a standard absorption X-ray would show as nearly featureless.

⚙ Under the hood

opticsdiffractionwave-physicsnear-fieldinterferencex-ray-imagingphotonics

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install