Diffraction at an object - diagram?

[ZedCar]

I was wondering if anyone would have a link to, or have, a diagram showing light wave diffraction at an obstacle?

That is, when it collides with an obstacle, then diffracts around the corners.

It's easy to find diagrams for slot experiments, but am having problems finding a good diagram for this.

Thanks!

 

[sophiecentaur]

I was wondering if anyone would have a link to, or have, a diagram showing light wave diffraction at an obstacle?

That is, when it collides with an obstacle, then diffracts around the corners.

It's easy to find diagrams for slot experiments, but am having problems finding a good diagram for this.

Thanks!

As it happens, the diffraction pattern from a slot (aperture) and the pattern from an obstacle the same width, are the same but inverse. This is not altogether surprising when you think that the slot is what you get when you take the obstacle away and vice versa. If you let the light from the slot add to the light from the obstacle, you get an unobstructed uniform resulting field.

So, for a long slot, you get a
sin(x)/x pattern and , for a single rectangular obstruction of the same size, you get a

1-sin(x)/x pattern.

The (optical) diffraction pattern for a slot is, of course, easier to see because your eyes are not blasted by all that unobstructed light that gets past a single obstacle. If you take a receiving antenna round behind a metal obstruction, however, it is often possible to detect a set of maxes and mins right where you'd expect to find a shadow.

http://www.chegg.com/homework-help/questions-and-answers/a-circular-obstacle-produces-the-same-diffraction-pattern-as-a-circular-hole-of-the-same-d-q1168676 and many more. I searched Google for "diffraction pattern obstacle".

 

[ZedCar]

Thanks sophiecentaur.

It was really a flat/straight obstacle, rather than a round obstacle I was looking for.

I should have been more clear on that.

Something like this:
http://www.google.co.uk/imgres?q=diffraction+pattern+obstacle&start=372&um=1&hl=en&tbo=d&biw=1920&bih=890&tbm=isch&tbnid=MMB_5UkCCUwOaM:&imgrefurl=http://fizik-fizik.blogspot.com/2010_01_01_archive.html&docid=XJ_aIqefGFA4cM&imgurl=http://4.bp.blogspot.com/_FAgA6-CHYr8/TUQNdArxW7I/AAAAAAAAAuQ/XQYhajZNTZk/s1600/untitled.bmp&w=840&h=304&ei=aegPUZmvAsWd0AW35oGgDQ&zoom=1&ved=1t:3588,r:92,s:300,i:280&iact=rc&dur=687&sig=111767905124275248331&page=10&tbnh=122&tbnw=317&ndsp=46&tx=98&ty=28
which is the only such diagram of its kind I can find on the internet!

 

[jtbell]

Here's a Java applet that displays diffraction patterns for various shapes. You can vary the size, and switch between apertures and obstacles.

http://www.falstad.com/diffraction/

 

[sardar]

I would be happy to provide a response to your question. Diffraction is a phenomenon that occurs when a wave encounters an obstacle or aperture and bends around it, spreading out into the region beyond. This can be observed with various types of waves, including light waves.

Unfortunately, I do not have a specific diagram to share with you, but I can offer some general information about diffraction at an object. When a wave encounters an obstacle, it will diffract around the edges of the obstacle, creating a pattern of alternating light and dark regions. This is known as the diffraction pattern.

The exact shape and size of the diffraction pattern will depend on the size and shape of the obstacle, as well as the wavelength of the wave. As you mentioned, there are many diagrams available online that show diffraction patterns for various obstacles, such as slits or gratings. These can serve as a good visual representation of the phenomenon.

It is also important to note that diffraction is not limited to just light waves. It can also occur with other types of waves, such as sound waves and water waves. In fact, the study of diffraction is an important aspect of wave physics and has many practical applications, such as in the design of antennas and microscopes.

I hope this information helps to answer your question. If you have any further inquiries about diffraction or other scientific concepts, please do not hesitate to ask. As scientists, we are always happy to share our knowledge and expertise with others. Best of luck in your search for a suitable diagram!