The fringe width in an interference pattern is directly proportional to the wavelength of light.
This means that:
- As the wavelength increases, the fringe width also increases.
- Conversely, if the wavelength decreases, the fringe width becomes narrower.
In practical terms, when using longer-wavelength light (like red), the bright and dark fringes in an interference pattern are spaced farther apart. With shorter-wavelength light (like blue or violet), the fringes appear closer together.
This relationship is important in experiments like Young’s double-slit, where changing the color (and thus the wavelength) of light directly affects the spacing between the interference fringes on the screen.