Definitions [2]
Definition: Diffraction of Light
The bending of light round the corners of the obstacles, or apertures, is called 'diffraction’.
Definition: Diffraction Pattern
“The intensity distribution upon the screen is called the ‘diffraction pattern’ of the aperture.”
Formulae [2]
Formula: Single Slit Diffraction
e sin θ = ±mλ (m=1,2,3,…)
Formula: Subsidiary Maxima
e sin θ = \[\frac{(2m+1)\lambda}{2}\]
Key Points
Key Points: Fraunhofer's Diffraction
- A single-slit diffraction pattern consists of a bright central band with alternating dark and faint bands on either side.
- The central maximum is the brightest and widest, and most of the incident light is concentrated in it.
- Diffraction becomes more prominent when the slit width is small, especially when it is comparable to the wavelength of light.
- Red light spreads more than blue light in diffraction, showing that diffraction depends on wavelength.
- Narrowing the slit increases the width of the central maximum, while widening the slit reduces diffraction and makes light propagation nearly rectilinear.
