Diffraction (Fraunhofer and Fresnel) Diffraction is the bending or spreading out of light when it passes through an opening or a curved surface. It's a f...
Diffraction is the bending or spreading out of light when it passes through an opening or a curved surface. It's a fascinating phenomenon that plays a crucial role in shaping the images we see in the real world.
Fraunhofer diffraction is a type of diffraction that occurs when light passes through a single slit. When light passes through the slit, it creates a series of bright and dark bands on the screen behind it. The dark bands are caused by constructive interference, where the light waves constructively interfere with each other, while the bright bands are caused by destructive interference.
Fresnel diffraction is a type of diffraction that occurs when light passes through a curved surface. When light hits a curved surface, it is refracted (bent) at the boundary between the air and the surface. This bending of light creates a series of light and dark bands on the screen behind the surface. The dark bands are caused by destructive interference, while the bright bands are caused by constructive interference.
Key Differences:
Slit diffraction: Single slit, constructive interference
Curved surface diffraction: Curved surface, destructive and constructive interference
Examples:
Slit diffraction: You can observe diffraction patterns on a screen by placing a light source behind a single slit.
Curved surface diffraction: You can observe diffraction patterns on a screen by placing a light source behind a curved lens or mirror