Physics III applets

Optics Bench

Build optical setups and see what they do.

• Ray optics: objects on a lawn, lenses, apertures and glass prisms. See what an eye and a screen see, ray traced on the GPU.
• Fourier optics (4f): diffraction, spatial filtering and phase contrast with scalar wave optics.
• Dispersion: wave packets in dispersive media, phase and group velocity, and thunder and whistlers to listen to.
• Rainbow: rays in a water drop, why there is a bow, the secondary bow and Alexander's dark band, polarisation.
• Interferometers: build cavities, Michelson, Mach–Zehnder and Sagnac interferometers on an optical table, with beam splitters, polarisation optics and a laser you can sweep. See the free spectral range and the finesse, and watch the field in a cavity build up. A Michelson as a Fourier-transform spectrometer, white-light fringes, and a scanning Fabry–Pérot.
• Gratings: a grating spectrometer with source and reference lamps. Calibrate it, and see why its resolution is set by the path difference across the grating: δλ/λ ≥ λ/2Nd. Includes PS03, exercise 11 (slit, double slit and grating).
• Polarisation: linear, circular and elliptical light as in Saleh & Teich 6.1: the wave along z, the ellipse in the x–y plane and the Poincaré sphere. Add polarisers and λ/2 and λ/4 plates and follow their Jones matrices, as in PS03, exercise 13.

Each name above links straight to that bench. Needs a browser with WebGPU: Chrome or Edge, Safari 26 or newer, or Firefox with WebGPU. There is also a desktop app.