Light Through Glass
From total internal reflection to wavelength division multiplexing, optical fibers carry the world’s data at the speed of light. These 10 simulations take you inside the fiber: watch rays bounce through step-index and graded-index cores, see pulses broaden from modal dispersion, combine wavelengths with WDM, and explore exotic photonic crystal fibers. Every demo reveals the physics that makes modern telecommunications possible.
The core physics of light guidance—how rays enter, reflect, and propagate through optical fibers.
Drag the light ray to explore Snell’s law at the boundary. Beyond the critical angle, light reflects completely—the foundation of fiber optics.
Visualize the cone of light that a fiber can capture. Rays within the acceptance angle propagate; rays outside leak away through the cladding.
Launch rays into a step-index fiber and watch them zigzag through the core by total internal reflection. Adjust launch angle and core diameter.
A parabolic refractive index profile bends rays in smooth sinusoidal paths. Higher-order modes travel faster at the edges, equalizing transit times.
How multiple propagation modes affect signal quality, and the critical difference between single-mode and multi-mode fibers.
Send a sharp pulse into multimode fiber and watch it broaden. Different modes travel different path lengths, smearing the signal over time.
Side-by-side comparison: a 9 µm single-mode core carries one clean mode while a 50 µm multi-mode core supports hundreds with increasing dispersion.
The technologies that push fiber optics from simple light pipes to the backbone of global telecommunications.
Up to 8 data channels travel simultaneously through one fiber, each at a different wavelength. Toggle channels and see the combined spectrum.
Periodic index variations create a wavelength-selective mirror inside the fiber. Tune the grating period and watch the reflection spectrum shift.
A pump laser excites erbium ions that amplify signal photons through stimulated emission. Explore gain, pump power, and the erbium energy levels.
A microstructured fiber with hexagonal air-hole arrays. Switch between solid-core and hollow-core designs, adjusting hole size and lattice pitch.