Young's double slit experiment (shallow slit and deep slit)

kevinfr0st

i have posted a video on youtube,where i did the double slit experiment,firstly with a shallow slit,then with a slit approx 35 times thicker,then did the experiment with out lens on laser,i would like to have a chat about what it all shows,and what it says to you (any one)
http://www.youtube.com/watch?v=Zns659ClKtY

Lok

On the thick slit, the abnormality might be explained by reflections between the 2 surfaces. That is usually why slits are thin.

The into the laser photos, is there any slit, aperture anything? how about the cameras aperture it has it's own effects.

Btw. One simple and clear way to see double slit patterns is through your eyelashes. while looking to a small source of light ( light bulb at 5m) close your eyes a bit so you see through your eyelashes. The pattern will appear in rainbow colors as the light has most of the visible in it.

kevinfr0st

thanks for your reply,the banding is no different just more of them,the photos in to the laser was straight in to laser (still had lens in laser) with dig cameras the processer (i think)likes to hex shapes that are round,with the pin hole shot i loaded at end of video it took 8 or 9 times to get the pin hole to look round and not hex,you can see the banding,i had also found out you dont need to shine laser through the slit,shine it on to a wall 5 feet or 10 or 20 and look through the slit at the dot,i also found out if you hold a double slit to your eye and hold up a lens the slit focas the immage,the strange thing is when the lens is removed the experiment dont work,you get banding inside the slit,like you see if you hold the slit to your eyes,
any more comments welcome

Lok

When you say "remove the lens" you mean the lens that focuses the laser? And if so how does the laser look like? I mean does it diverge in a huge angle? Are you sure there are no other patterns "without the lens" as for an unfocused laser they will be extremely faint ( try photographing with a very long exposure time. Plus they might overlap if slit is too big.

The other effects of seeing patterns through slit close to the eye are known and documented.

kevinfr0st

yes the lens that focuses it and the small spring,to look at the minute laser head would need a microscope,seems like a small crystall,iv got a few pic on my pc with photos of the laser on with no lens,if you look at some of my older videos (laser with no lens through a macro mesh) you can see the pattern of laser light on ceeling,iv taken loads of pic in to the laser (older ones iv broke ) they were £1 laser levels (crap but wanted the laser)and still same patterns,i will load some on to my flicker page iv got some taken of sun light through the slit,link here if any one wants to look
http://www.flickr.com/photos/46673813@N06/
will load laser with out lens pic bit later got pop out
thanks for you comments