Grating Constant Calculator

This calculator determines the grating constant (d) of a diffraction grating based on wavelength, diffraction order, and incident angle.

Input Parameters

Calculation Results

Calculation Formula

d = λ / (m * sin(θ))

Where:
d = grating constant (in meters)
λ = wavelength (in meters)
m = diffraction order
θ = incident angle (in radians)

Grating Constant Calculator Usage Guide

Learn how to use the Grating Constant Calculator and understand its working principles

How to Use This Calculator

  1. Enter the wavelength (λ) of the light in nanometers (nm). This is typically in the visible spectrum range of 400-700 nm, but can be for other wavelengths too.
  2. Specify the diffraction order (m). This is usually an integer (1, 2, 3, ...), with the first order (m=1) being the most common.
  3. Input the incident angle (θ) in degrees. This is the angle at which the light hits the grating surface relative to the normal (perpendicular line).
  4. Click the "Calculate" button to compute the grating constant.
  5. The results will be displayed in both meters and nanometers.

Understanding the Grating Constant

The grating constant (d) is the distance between adjacent slits in a diffraction grating. It's a critical parameter that determines how the grating disperses light. The formula used is:

d = λ / (m * sin(θ))

Where:
• d = grating constant (the distance between slits, in meters)
• λ = wavelength of light (in meters)
• m = diffraction order (an integer)
• θ = incident angle (in radians)

Example Calculation

Suppose you have a diffraction grating with a wavelength of 500 nm (0.5 × 10-6 meters), using the first order (m=1), and the light hits at an angle of 30 degrees:

d = (0.5 × 10-6) / (1 * sin(30°)) = 1.0 × 10-6 meters = 1000 nm

This means the slits in the grating are 1000 nm apart.