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About this tool
A tool that simulates wave interference patterns, allowing users to visualize how waves interact with each other. Users can adjust parameters such as wave frequency, amplitude, and phase to see how they affect the resulting interference pattern.
Wave Interference Simulator animates the superposition of sinusoidal waves in real time, summing y = A·sin(kx − ωt + φ) with k = 2π/λ and ω = 2πf so you can watch amplitude, wavelength, frequency and phase reshape the combined wave as you drag them. It covers six modes — single wave, two-wave interference, standing waves, 2D ripple tanks, Young's double slit, and a custom formula box — with a phasor diagram and live resultant amplitude alongside. It is built for physics students and teachers who need to see why two identical waves cancel when one is shifted by π.
Open Wave Interference Simulator on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
The rotating phasor diagram shows why the resultant amplitude is what it is, turning the phase difference from an abstract number into a vector sum you can see.
Slit separation, screen distance and wavelength are entered in physical units with 405 nm, 532 nm and 633 nm laser presets, so the fringe pattern matches what a bench setup would produce.
Custom mode compiles an expression in x, t, A, k, w and phi against a restricted maths scope, so you can plot a beat, a chirp or a damped wave that no preset covers.
The travelling-wave form y = A·sin(kx − ωt + φ), where the wavenumber k is 2π divided by the wavelength and the angular frequency ω is 2π times the frequency times the speed setting. Two waves are combined by straight addition of their displacements at each point, which is what linear superposition means.
As the Young two-slit intensity I(y) = cos²(π·d·y / (λ·L)), where d is the slit separation, L the slit-to-screen distance and λ the wavelength; if you give the slits a finite width a, that is multiplied by the single-slit envelope sinc²(π·a·y / (λ·L)). With the built-in 532 nm preset, 0.2 mm separation and a 1.5 m screen distance, the bright fringes come out about 4 mm apart.
Because a phase shift of π is exactly half a wavelength, so every crest of one wave lands on a trough of the other and the displacements sum to zero. Complete cancellation only happens when the two amplitudes are equal — with unequal amplitudes the resultant is the difference between them.
Because the simulator applies a 1/√r amplitude falloff from each point source, matching the way energy on a two-dimensional surface spreads over a circle whose circumference grows with the radius. That is why interference bands stay sharpest near the sources and wash out toward the edges.