My Young's slits experiment doesn’t work. I mean I tried to see wave effect of light but I didn’t see any thing expect particles! I’ve sent you a pic of my laser and a short video of the experiment. Is there any problem you think?
[Physics] What’s the problem with the Young slits experiment
double-slit-experimentexperimental-physicsexperimental-techniquehome-experiment
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Best Answer
The angle between maxima in the double-slit pattern is $$ \theta \approx \frac\lambda d $$ for wavelength $\lambda$ and slit separation $d$. I wild-guess that the slits in your photograph are about 5 cm apart, so your diffraction peaks should be separated by $$ \frac\lambda d = \frac{\rm 500\,nm}{\rm50\,mm} = 10^{-5}\rm\,radian $$ which is too small for you to resolve the peaks even if you were illuminating both slits at once (which you're not).
So, your slits are too far apart. Try splitting your beam into two parts by straightening out a staple from a stapler and shining the laser on the staple; that works pretty well. You'll need to jerry-rig some mount for the staple and laser, since the diffraction pattern isn't obvious unless you can get it on the other side of the room.
Here's a quick setup I threw together. I stood a staple up on a pencil eraser and used it to split a laser beam:
The spot is on a wall about four meters away:
From up close, you can see there are about three or four maxima per fingers'-width:
A hair is narrower than a staple, so you'd more distance between maxima if you split the beam with a hair.