Double Slit Experiment — Discover Physics

Mode

Wavelength λ (nm) 550 nm

Particle Rate 10 /s

Number of Slits

Slit Width a (μm) 50 μm

Slit Separation d (μm) 150 μm

Screen Distance L (m) 2.0 m

Intensity Graph Diffraction Envelope Wavefronts

Fringe Width β—

Central Max Width—

Angular Spread—

Particles Hit0

Fringe Width

β = λL/d

λ: wavelength, L: screen distance, d: slit separation

Double Slit Intensity

I = I₀ cos²(πd sinθ/λ)

Interference pattern from two coherent sources

Single Slit Minima

a sinθ = mλ

a: slit width, m: ±1, ±2, ...

Path Difference

Δ = d sinθ = nλ (maxima)

Constructive when path difference = whole wavelength