Diffraction can be used to measure the wavelength of light by observing the pattern formed when light passes through a diffraction grating or a single slit and analyzing the angles at which bright fringes appear.
In a diffraction grating setup:
- A light source shines through a grating that has many closely spaced slits.
- The light diffracts through the slits, and constructive interference occurs at specific angles.
- These angles correspond to bright fringes on a screen.
By measuring the distance between the fringes on the screen and the distance from the grating to the screen, and knowing the spacing between the slits in the grating, the wavelength of the light can be determined.
This method is precise and commonly used in spectrometers. It relies on the fact that each wavelength produces a unique pattern, so by analyzing the angles of the bright spots, the wavelength can be calculated accurately.