Fresnel diffraction
Close-range wave spreading
Fresnel diffraction is a type of light diffraction occurring when either the light source or the observation point is close to the diffracting object, so that wavefront curvature matters.
This contrasts with Fraunhofer diffraction, where distances are large enough that waves can be treated as parallel.
Fresnel diffraction produces complex patterns that vary with distance from the aperture or obstacle.
- Huygens' principleWave propagation geometric model
- wavefrontSurface of equal phase
- optical path lengthEffective light travel distance
- near-fieldRegion adjacent to source
- interferenceUnwelcome involvement in affairs
coherence · penumbra · boundary conditions · superposition · phase shift · pinhole cameras · fringes · microscopy · holography · Huygens · slit · pattern · wavelength · intensity · light · phase · optics · illumination