The Minimum Angular Spread Due to Diffraction

The Concept of Diffraction-Induced Spread

Diffraction-induced spread refers to the phenomenon where waves spread out as they pass through an aperture or around objects. This spreading out of waves occurs when the wavelength of the incident wave is similar in size to the aperture or obstruction it encounters.

When a wave encounters an obstruction or passes through a small aperture, diffraction causes it to spread out. This spreading out results in the wave interfering with itself, leading to various diffraction patterns that can be observed.

Calculating Minimum Angular Spread Due to Diffraction

The formula to calculate the minimum angular spread due to diffraction is given by:

Minimum angular spread due to diffraction (θ) = λ/b

Given:

• Wavelength (λ) = 633 nm = 633×10⁻⁹m
• Beam diameter (b) is 1 mm (converted to meters)

Substitute the values into the formula:

Minimum angular spread due to diffraction (θ) = 633×10⁻⁹m / 1

Minimum angular spread due to diffraction (θ) = 633×10⁻⁹m

Therefore, the minimum angular spread due to diffraction is 633×10⁻⁹m.