Setup — Source → Slits → Screen
Screen Pattern & Intensity Curve
Coloured strip = fringe pattern | Solid curve = I(θ) | Dashed = single-slit envelope
Wavelength
380 nm550 nm700 nm
Parameters
Slit separation d4.0μm
1μm12μm
Slit width a1.0μm
0.2μm3μm
Screen distance L50.0cm
10cm100cm
Measurements
Fringe spacingβ = λL/d = 68750.00 mm
Condition (bright)d·sinθ = mλ
Condition (dark)d·sinθ = (m+½)λ
Missing order at md/a = 4.0
Physics
Young's experiment demonstrates wave nature of light. Two coherent sources produce fringes wherever path difference equals a whole number of wavelengths. The slit width a controls the single-slit envelope that modulates the fringe pattern.