Which term describes scattering from targets much smaller than the wavelength?

Which term describes scattering from targets much smaller than the wavelength?

• A. Specular Reflection
• B. Rayleigh Scattering
• C. Diffraction
• D. Absorption

Answer: (B)

When the scatterer is much smaller than the wavelength, the wave can’t “resolve” the object as a detailed obstacle. Instead, the incident field induces a tiny dipole in the particle, and this dipole radiates scattered light. This behavior is known as Rayleigh scattering. A hallmark of this regime is a strong dependence on wavelength: the scattered intensity goes roughly as 1/λ^4, so shorter wavelengths scatter much more than longer ones (which explains why blue light is scattered in the atmosphere). Specular reflection describes reflection from large, smooth surfaces where the angle of incidence equals the angle of reflection, not small subwavelength targets. Diffraction is the bending of waves around obstacles and through openings and becomes prominent when features are on the order of the wavelength, not strictly tied to subwavelength scatterers. Absorption involves energy entering the material rather than being re-radiated as scattered light, so it isn’t the scattering process described here.

When the scatterer is much smaller than the wavelength, the wave can’t “resolve” the object as a detailed obstacle. Instead, the incident field induces a tiny dipole in the particle, and this dipole radiates scattered light. This behavior is known as Rayleigh scattering. A hallmark of this regime is a strong dependence on wavelength: the scattered intensity goes roughly as 1/λ^4, so shorter wavelengths scatter much more than longer ones (which explains why blue light is scattered in the atmosphere).

Specular reflection describes reflection from large, smooth surfaces where the angle of incidence equals the angle of reflection, not small subwavelength targets. Diffraction is the bending of waves around obstacles and through openings and becomes prominent when features are on the order of the wavelength, not strictly tied to subwavelength scatterers. Absorption involves energy entering the material rather than being re-radiated as scattered light, so it isn’t the scattering process described here.