Single Slit Diffraction Lab - Physics Simulations

t = 0.00s

Slit Beam Intensity Envelope

Live Telemetry & Summary

Laser Wavelength (λ) & Color Mapping:
The visualization color changes to match the physical visible light spectrum:
• Violet/Blue (400-480nm): Shortest wavelength. The wavelets diffract at narrower angles, resulting in a narrower central maximum envelope.
• Green (490-550nm): Medium wavelength and moderate spread.
• Red (600-700nm): Longest wavelength. The wavelets diffract at wider angles, resulting in a broader central maximum envelope.

What does "Simulate" do?
It animates the propagation of spherical wavelets (Huygens' Principle) traveling outward from the slit aperture to the screen. The diffraction pattern and intensity envelope ($I(\theta)$) show the steady-state, time-averaged distribution.

Central Max Width (2θ₀):0.41°

Slit Width (a):0.15 mm

Wavelength (λ):532 nm

Variable Adjuster

Wavelength (λ)532nm

400700

Slit Width (a)0.15mm

0.050.3

Single-Slit Diffraction

DIFFR

Diffraction occurs when waves encounter an obstacle or pass through an aperture. According to Huygens' Principle, every point on the wavefront inside the slit acts as a source of spherical wavelets. The interference of these wavelets produces a central bright maximum flanked by secondary maxima of rapidly decreasing intensity.

\sin\theta = \frac{m\lambda}{a}, \quad I(\theta) = I_0 \left(\frac{\sin\beta}{\beta}\right)^2

Whiteboard Solver Steps

Step 1

Single-Slit Diffraction Minima Condition

Minima (destructive interference) occur where the path difference between light from top and bottom edges of the slit equals an integer multiple of the wavelength.

a \sin\theta = m \lambda \quad (m = \pm 1, \pm 2, \dots)

Step 2

Central Maximum Angular Width

The central bright maximum propagates outward with a total angular divergence width of approximately 0.406 degrees.

2\theta_0 = 2 \arcsin\left(\frac{\lambda}{a}\right) = 2 \arcsin\left(\frac{532 \text{ nm}}{0.15 \text{ mm}}\right) \approx 0.406^\circ