Diffraction Grating Simulator

Geometric Constraints in Wave Optics

Grating View

Physical grating structure (top view)

Diffraction Pattern

Intensity distribution vs angle

Parameters

Presets

Display Options

Animation

Animation speed: 1.0x

Theory

Diffraction Grating Equation

d·sin(θ) = m·λ

Where d = slit spacing, θ = diffraction angle, m = order (0, ±1, ±2, ...), λ = wavelength

Intensity Distribution

I(θ) = I₀ · [sinc(β)]² · [sin(Nα)/sin(α)]²

Where β = (π·a·sinθ)/λ, α = (π·d·sinθ)/λ, N = number of slits, a = slit width

Key Principles

  • Geometric Constraint: Equally spaced slits create interference pattern
  • Single Slit Envelope: Modulates overall intensity (sinc² function)
  • Multi-Slit Interference: Creates sharp principal maxima
  • Principal Maxima: Occur at angles where path difference = m·λ
  • Secondary Maxima: N-2 smaller peaks between principal maxima

Applications

  • Spectroscopy - separating light into component wavelengths
  • Wavelength measurement - precise determination of light properties
  • Optical communications - wavelength division multiplexing
  • Laser systems - beam shaping and filtering

Measurements

First Order Angle: -
Angular Separation: -
Resolving Power: -
Dispersion: -