Fresnel diffraction; geometrical shadow

In summary, Fresnel diffraction is a phenomenon where waves bend and spread out when passing through an aperture or around an object. It differs from Fraunhofer diffraction in that the distance between the source and object is comparable to the wavelength of the wave. The geometrical shadow is a region where no light can pass through due to the obstruction of the light source, and it is not affected by Fresnel diffraction. However, the edges of the shadow may exhibit diffraction effects. Fresnel diffraction is used in various real-world applications, such as in astronomy, microscopy, and the design of optical devices.
  • #1
j-lee00
95
0
What is geometrical shadow qualitatively? please don't refer me to hyper physics
 
Science news on Phys.org
  • #2
A geometric shadow is a set of points (or a region of space) where drawing a line between said points and a source always results in the line intersecting some obstacle.

A looser explanation would be that a geometric shadow is the shadow objects would possesses in the absence of diffraction.

Claude.
 
  • #3
Thanks
 

FAQ: Fresnel diffraction; geometrical shadow

What is Fresnel diffraction?

Fresnel diffraction is a phenomenon that occurs when a wave, such as light, passes through an aperture or around an object. It results in the bending and spreading out of the wave, creating a diffraction pattern.

How is Fresnel diffraction different from Fraunhofer diffraction?

Fresnel diffraction occurs when the distance between the source and the diffracting object is comparable to the wavelength of the wave, while Fraunhofer diffraction occurs when the distance is much greater. This results in different patterns of diffraction, with Fresnel diffraction producing a more complex pattern due to the curvature of the wavefront.

What is the geometrical shadow?

The geometrical shadow is the region behind an object where no light can pass through due to the complete obstruction of the light source. It is created when the object blocks the direct path of the light, resulting in a sharp, well-defined shadow.

Can the geometrical shadow be affected by Fresnel diffraction?

No, the geometrical shadow is not affected by Fresnel diffraction as it is a result of the complete obstruction of the light source. However, the edges of the geometrical shadow may exhibit diffraction effects.

How is Fresnel diffraction used in real-world applications?

Fresnel diffraction is used in various applications, such as in astronomy to study the diffraction patterns of stars and in microscopy to enhance the resolution of images. It is also used in the design of optical devices, such as lenses and mirrors, to minimize diffraction effects and improve image quality.

Similar threads

Replies
2
Views
2K
Replies
36
Views
3K
Replies
3
Views
711
Replies
1
Views
930
Replies
1
Views
629
Back
Top