optics

Optical Interference & Diffraction

See light waves interfere and diffract in 3D: Young's double slit, single-slit diffraction, and diffraction gratings. Visualize wavefront overlap and the resulting intensity patterns.

Interference

A-Level

When waves overlap, they superpose. Constructive interference occurs when waves are in phase (path difference = nλ); destructive interference when out of phase (path difference = (n+½)λ). Diffraction gratings produce sharp, well-separated maxima.

Wavelength550nm

Slit Width10μm

Lines/mm300

📐 Formulas

d\sin\theta = n\lambdaMaxima condition for gratings

a\sin\theta = n\lambdaMinima condition

\theta = 1.22\frac{\lambda}{D}Resolution limit

📋 Syllabus

AQA3.3.3

EdexcelTopic 5