Single Slit Diffraction Calculator
Enter slit width, light wavelength, and screen distance to compute diffraction minima angles, positions, and the central maximum width.
Slit Parameters
Typical lab slit: 10–500 μm
Visible light: 380–700 nm
First Minimum Angle
—
θ₁ = arcsin(λ/a)
Central Max Half-Width
—
y₁ position on screen
Central Maximum Full Width
—
from −y₁ to +y₁ (distance between first minima)
Diffraction Minima
Dark fringe positions where a·sin(θ) = m·λ
| Order (m) | Angle θ (°) | sin(θ) | Position y (mm) |
|---|
Enter parameters above and click Calculate.
Summary
Enter slit width, light wavelength, and screen distance to compute diffraction minima angles, positions, and the central maximum width.
How it works
- Enter the slit width (a) in micrometers — the physical opening the light passes through.
- Enter the light wavelength (λ) in nanometers (visible range: 380–700 nm).
- Enter the screen distance (L) in meters — how far the observation screen is from the slit.
- Select how many minima orders to display using the slider (up to ±10).
- Click Calculate to see each minimum's angle, screen position, and central maximum width.
Use cases
- Solve single-slit diffraction problems in university optics courses.
- Verify lab measurements of dark fringe positions against theory.
- Explore how slit width affects the spread of the diffraction pattern.
- Compare patterns produced by different wavelengths of light.
- Design optical setups where diffraction spread must be controlled.
- Understand the resolution limit imposed by aperture size in imaging systems.
Frequently Asked Questions
Last updated: 2026-07-01 ·
Reviewed by Nham Vu