Overview: Diffraction of Light

The bending of light round the corners of the obstacles, or apertures, is called 'diffraction’.

“The intensity distribution upon the screen is called the ‘diffraction pattern’ of the aperture.”

e sin θ = ±mλ (m=1,2,3,…)

e sin θ = \[\frac{(2m+1)\lambda}{2}\]

• 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.