Young's double slit interference in 3D

Direct answer

Change λ, d, D and slit width and see the interference pattern, the intensity curve and the fringe width β = λD/d in 3D.

Wavefronts from the two slits overlap. Where they arrive in step the screen is bright; half a wavelength out of step it is dark. The yellow curve is the intensity.

Simulation

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Young's Double Slit Experiment in 3D

Wave optics

Wavelength λ (nm) 550 nm

Slit separation d (mm) 0.5 mm

Screen distance D (m) 1 m

Slit width a (μm) 50 μm

Drag to rotate, two fingers or right-drag to pan, scroll or pinch to zoom. The toolbar has views, cutaway, measure and “show the maths”.

What's happening? Wavefronts from the two slits overlap. Where they arrive in step the screen is bright; half a wavelength out of step it is dark. The yellow curve is the intensity.

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Where it is in NCERT: Class 12 Physics Part II, “Wave Optics” (Huygens Principle, Refraction and Reflection of Plane Waves using Huygens Principle, Coherent and Incoherent Addition of Waves, Interference of Light Waves and Young's Experiment) · ncert.nic.in
Topic notes and formulas: Wave Optics
Printable formula sheet
Chapter-wise JEE Main PYQs (11)