Barrier slit spacing is schematic; the pattern uses the real values
Presets
Wavelength550 nm · green
Fringe spacing5.50 mm
Visible fringes9
Slits2 · a = 0.020 mm
Photons landed0
Relative intensity across the screen. The filled curve is the two-slit pattern I = sinc²(π·a·sinθ/λ)·cos²(π·d·sinθ/λ); the dashed line is the single-slit diffraction envelope that fades the outer fringes. The bracket measures the fringe spacing Δy = λL/d between the central maximum (m = 0) and its neighbour (m = 1).