YDSE

Young's Double Slit Experiment

Wave Optics Simulator · v2.0

WAVE OPTICS

Parameters

Wavelength λ 550 nm

visible spectrum: 380–700 nm

Slit Separation d 0.50 mm

smaller d → wider fringes

Screen Distance D 1.00 m

larger D → wider fringes

Slit Width a 0.05 mm

controls single-slit envelope

Visualisation

Measurements

Fringe Width β

—

Angular Fringe

—

mrad

Max Order n

—

fringes

Path Diff at n=1

—

= λ

01 · Optical Setup

02 · Intensity Profile I(y)

03 · Phasor Diagram

Constructive Interference

Bright fringes occur when path difference equals an integer multiple of wavelength — waves arrive in phase.

Δ = d·sinθ = nλ
y_n = nλD/d

Destructive Interference

Dark fringes occur when path difference is a half-integer multiple of λ — waves cancel exactly.

Δ = (2n+1)λ/2
y_n = (2n+1)λD/2d

Diffraction Envelope

Single-slit diffraction modulates the double-slit pattern, zeroing intensity where sinc²(πay/λD) = 0.

I = I₀·sinc²(β/2)
·cos²(δ/2)