Getting started

PhotonLab runs in any current browser. There is no account and nothing to install. Open photonlab-gamma.vercel.app and the double-slit experiment starts on its own.

The first time it opens, the app spends a fraction of a second timing the solver on your device. It uses that measurement to pick a grid size it can run smoothly: 512 × 512 cells on most laptops, smaller on older phones. You can override it later under Simulation → Grid.

Five minutes with it

1. Pause and step. Press Space to pause. Press . to advance a few steps at a time and watch the wavefronts move through the slits.
2. Change the experiment. Open the menu with the flask icon at the top and choose Convex lens. Each experiment comes with its own sources and probes.
3. Look at intensity. Press T. Instead of the oscillating field you now see the time-averaged intensity, which is what a camera or your eye would record. The focus of the lens becomes a bright spot.
4. Draw something. Press R for the rectangle tool, pick Silicon in the inspector on the right and drag a block into the beam. The field reacts immediately; there is no rebuild step.
5. Measure. Press P and click behind your block to place a probe. Press A to open the analysis panel. Signal shows the field at the probe over time, Spectrum shows which wavelengths are present.

Every change can be undone with Ctrl Z.

Install it as an app

PhotonLab is a progressive web app. In Chrome or Edge use Install app in the address bar; on iOS use Share → Add to Home Screen. The installed version works offline.

What you need

• A browser from 2023 or later (Chrome, Edge, Firefox, Safari 16.4+). The solver uses WebAssembly SIMD and the picture is drawn with WebGL 2.
• Any CPU will do. On slower machines the grid is smaller and the status bar shows when the device limits the speed.

If something does not work, the issue tracker is the right place to tell me.