Optics: Fraunhofer diffraction - adjustable slit | MIT Video Demonstrations in Lasers and Optics

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12 жыл бұрын

Optics: Fraunhofer diffraction - adjustable slit
Instructor: Shaoul Ezekiel
View the complete course: ocw.mit.edu/RES-6-006S08
License: Creative Commons BY-NC-SA
More information at ocw.mit.edu/terms
More courses at ocw.mit.edu

Пікірлер: 50

@kirknay 4 жыл бұрын

I found this after PBS's latest Spacetime video mentioned using your index and middle fingers over your eye to see something similar.

@prof_hu 4 жыл бұрын

Same for me.

@KartikSharma1607 11 жыл бұрын

relly nice. Helping me a lot in college. Thanks

@jakobberzins3855 2 жыл бұрын

The diffusion must occur at the edges of the slit, which makes diffraction occur for a single slit because of 2 edges. Not many sources explain this well.

@jakobberzins3855 2 жыл бұрын

I wonder if when physicists detect which slit in the double slit experiment if they are just destroying the coherence of the light. Hence no diffraction pattern.

@bellinivernon 11 жыл бұрын

Exelente !

@vishnoinigam1648 7 жыл бұрын

in second video with circular apertures when he vary the distance between pinhole and slit then why it happens so that when he reduces the distance there are larger fringes and when he increases it there are fewer fringes

@siddharthgandhi7937 6 жыл бұрын

Thanks

@sidewaysfcs0718 9 жыл бұрын

when the distance between two null minimums is about 2.5 cm, the slit width is 50 micrometers

@samarthd9948 2 жыл бұрын

Yes sir, you're right

@thewanderers97 4 жыл бұрын

Enlightening

@sussusamogus8860 Жыл бұрын

Brilliant

@pranayreddy007 9 жыл бұрын

fraunhofer diffraction means rays diffractio of ray by using converging lens and and usual diffraction means without any lens

@anshukumar-yn4yn 2 жыл бұрын

Is convex lens used for focussing wave front after passing through slit????

@anupamsuman4037 7 жыл бұрын

is there any specific reason to use reflection of the laser light?

@jhyland87 6 жыл бұрын

I was wondering that as well.

@mielole 6 жыл бұрын

I think the laser was too long to fit in front of the slit and, additionaly, was obstructing the slit. Thus, it was moved and a reflection system was put in place. It works just as well with direct light.

@trk3294 6 жыл бұрын

We use this technique generally to allow the laser beam to diverge and increase its spot size by allowing it to have a longer optical path. This technique is described by the far field radiation pattern which is a region of the electromagnetic field. And the parameters such as Power radiated, radiation intensity, Power pattern, Directivity, Gain etc are calculated from Far field.

@manavshetty4449 6 жыл бұрын

The reason is simple. It is to create a huge distance btw the slits and the source.... as for fraunhofer diffraction huge distances are required

@anshikapal8884 4 жыл бұрын

Laser light is more coherent than ordinary light .

@NikitaNair 3 жыл бұрын

Wow!!!

@shahramshahram412 2 жыл бұрын

Light concentrators make the strips

@rainbow1000ish 10 жыл бұрын

Can anybody tell me what's the difference between Fraunhofer diffraction and the diffraction at a normal way??

@coffeedence1511 9 жыл бұрын

I'm not sure, but I would say that the difference is in the approximation of Fresnel-Kirchoff equation. If I'm not wrong, the Fraunhofer diffraction is an approximation valid when the source (the incident waves are plane waves (in this case the Laser Beam)) and the screen (In this case 200 cm) are very far from the slit. If the screen is near to the slit and the incident waves are spherical, we've got Fresnel Diffraction.

@puhbrox 3 жыл бұрын

All I'm getting from this is that light is really powerful and it's bouncing off the slit in a way that makes it divide (but in reality it's just because the light is not a particle dividing but a wave dividing)

@alcatraz766 2 жыл бұрын

Interesting theory but I'm afraid you're wrong, it actually due to the wave nature of light, the bright spots represent the spots with constructive interference and the blank ones representing the destructive interference.

@zenvir1680 6 жыл бұрын

I did this experiment at home with a lazer and slit made by sticking two razor blades with tape.

@simranbaghla3381 6 жыл бұрын

Zen vir grt

@thorsten8554 4 жыл бұрын

Did this too today ! --> kzfaq.info/get/bejne/ftKjhrCjr5i2d3k.html

@Sushil2k4 2 жыл бұрын

@manjuldahal440 4 жыл бұрын

@parisian9933 2 жыл бұрын

No offense intended but he looks and speaks a bit like Howard Wolowitz xD Great Content btw :)

@jamesprince9041 8 жыл бұрын

How do we know that the interference pattern is not the result of quanta particles following the pattern of gravitational waves between the source and target. If gravitational waves exist, the duality of light quanta as both a wave and particle will be negated, a light particle would only appear as a wave as it traverses the valleys and crests of gravitational waves, because light is bound to gravity. Light is affected by gravity, gravity affects spacetime, and photons must follow a path in spacetime. As spacetime curves the path photons take is changed

@ahmadmuaz5360 3 жыл бұрын

Boleh dh aq belajaq kat mit😤

@jamesovenden3833 7 жыл бұрын

His voice reminds me of the european immigrants that aren't quite american on family guy

@mortirius1 7 жыл бұрын

Im a little confused I thought it was only supposed to have two areas of light intensity when the double slit is observed but here I'm seeing a diffraction pattern thats only supposed to happen when there is no observer. Can someone explain why

@snehalsha6476 5 жыл бұрын

allan J this is not the quantum scale

@aditya_asundi 11 ай бұрын

Aaditya sir if you're watching this, hi 👋

@leewilliam3417 6 ай бұрын

Mmmmm😊

@zenext7764 4 жыл бұрын

Improve video quality , guys.

@anoopkrishna20000 3 жыл бұрын

Vdeo ws 8 yrs ago

@rainbow1000ish 10 жыл бұрын

Can anybody tell me what's the difference between Fraunhofer diffraction and the diffraction at a normal way??

@antiTamtaSquadLeader 2 жыл бұрын

In the case of fraunhofer diffraction the wavefront is a plane wavefront that means the light source is at infinity. If the "normal" case is of diffraction of light of a source at infinity then it is fraunhofer but if there is a finite distance then it's fresnel diffraction

@rainbow1000ish 2 жыл бұрын

@@antiTamtaSquadLeader oh God this comment is 7 years old

@1eV 2 жыл бұрын

@@rainbow1000ish feeling old? XD

@rainbow1000ish 2 жыл бұрын

@@1eV omg this is 7 years old Now i have no idea what i was even asking about 😂🤣🤣

@1eV 2 жыл бұрын

@@rainbow1000ish understandable