So if we have a polarizing beamsplitting cube and we send a single photon into it with a polarization angle at 45 degrees to the reflect (and pass through) angles, what happens to it?
Printable View
So if we have a polarizing beamsplitting cube and we send a single photon into it with a polarization angle at 45 degrees to the reflect (and pass through) angles, what happens to it?
Random exit on either face or a small chance of adsorbtion..Quote:
Originally Posted by maxh
conservation of energy says you can't create another one, and there is nothing as far as nonlinear optics goes to split it into two lower energy photons, so your choices are adsorption, or emission down one path.
Steve
where are you going to get one photon?
JDSU works on single photon diode lasers for ultra secure communications. You can't intercept a single photon transmission without disturbing it. There is also the Free Electron Laser. I believe there was one other.
Quote:
Originally Posted by Laser Ben
how much information can you pack into a single photon?
Well, dealing with such small quantities we enter the realm of quantum mechanics. This is a world where strange things happen.Quote:
Originally Posted by maxh
If measured, it will be found that the photon either passes through or is reflected with a 50% probability. If you don't measure it however, the photon will both pass through and be reflected! To further complicate matters, one could perhaps even set up a Stern-Gerlach type experiment.
At least 1 qubit!Quote:
Originally Posted by Laserman532
Thanks Tocket for wasting 30 minutes of work-time for my employer and making my head hurt...again!
" Stern-Gerlach type experiment."
:)
This explains it super easy
http://www.youtube.com/watch?v=VDmbdTtcoPM
Actually...no it didnt. Back in the old days during geometric optics course we had to draw (by pencil i might add) ray traces as particles, then the next year during wave optics course we had to ray trace as wave fronts...Why??? because no one knows whether "photons" are waves or particles (it is an electromagnetic something or other) or....Something else completely!!! (insert scary music here).:pQuote:
Originally Posted by Snilton
But to answer OP question- A single photon going through a PBS cube more than likely will be completely dispursed and absorbed due to scattering effects of the material:)
Isnt that what the video kinda said?Quote:
Originally Posted by Laserman532
You said "this explains it super easy" But it didnt explain what OP asked. This did explain an experiment on how to attempt to decipher / measure how particles worked and later how particles act as waves. My point is that due to a photon being a vague understanding one needs to treat it both ways. His conclusion was not conclusive IMO. Any way...this topic has fallen WAYYYYY outside my circle of concern:)Quote:
Originally Posted by Snilton
I still stick with it will be absorbed (probably at the surface and if not there...shortly thereafter):D
oh yeah, right..
If one photon would be absorbed, wouldnt every be too?
Good Point! - I guess this needs to be explained by someone far beyond my pay grade...and I am un employeed. Tocket probably hit it best so far, I never studied quantum mechanics, it appears tocket has...therefore I go with what he says. (it is still theoritical at best anyway) The trick from what I undersand so far is it if is being watched, it acts differently. What if 10 different people watch it differently at different angles:confused:Quote:
Originally Posted by Snilton
Damn...now I am COMPLETELY in Q4 activity:p
Wasn't there something along the same lines of this with a single electron + Young's slits? You just got a pattern of target dots scattered everywhere... :confused:
I remember watching a program about it on BBC4, presented by some rock stars son of a famous physicist, and they explained it REALLY well.
Dan
Edit: This isn't the clip I meant, but is about the same topic: http://www.youtube.com/watch?v=ZJ-0PBRuthc
As a PhD student I doubt I am far beyond your pay grade. I did study some quantum mechanics, but mostly quantum chemistry. It was about 1½ years ago I took the QM course and this knowledge seems to fade very quickly. :p
Here are some thoughts anyway.
How do you see a photon? Well, you get hit by it... in the eye, of course... how else? A photon/electron/whatever cannot know it is being observed. They can, of course, be measured, but it is impossible to measure anything without changing it. In other words, the act of measurement collapses the wave function. I'm not sure of how they actually determine which slit the particle passes through, but regardless of the method it will interfere with the quantum state of the particle.
I actually like the video. Naturally it is severely simplified and not completely correct from a QM perspective, but I think it does a pretty good job of explaining it. Understanding QM is impossible, so don't try it, unless you want to end up in the loony bin.
In modern quantum mechanics there aren't really any particles, only wave functions. Everything can be described with a wave function!
Now, back to the actual topic. The probability of a single photon being absorbed or scattered by the cube is fairly low. In fact these probabilities are the same as the relative beam losses of the cube.
So what happens if we observe the outcome from behind the slit? If there is a wavefront aberation it would be present then instead of intefering with the initial launch of said materials? What if the target was the observer? What is the theory ofthe Planck constant here? H bar = h/2pi ? Possible that the photon hitting the target created a display of particles from the target making the waves?
Either way, wouldn't you be directly or indirectly measuring it? :confused:
Yes this is true...hard to be a "fly on the wall" if it destroys the outcome.....
I will ponder this while working on coaxing multiple coherent photons from a device I am working with...
0 or 1 I would imagine...Quote:
Originally Posted by Laserman532
-Adam
Well, we may never know the answer and would it really matter if we knew the answer...not likely.
BUT- I give cudos to the OP for an EXCELLENT QUESTION no matter how irrelevant the answer.:)
Thank you, everybody, for the replies to my first post!
I found my way here recently while investigating ways to make a variable-color laser pointer, which is something I've dreamed of for at least a decade. Just recently I picked up a $1 cigarette lighter/laser pointer combo with which to entertain the dog, and it renewed my interest that had waned over the past few years. Luckily, rog8811 became my new hero just weeks before I hit the net with my queries!
Chemistry's my degree, and while I had a fair dose of physics and quantum mechanics, I haven't managed to incorporate them into my thoughts over the past several years... nice and rusty. ;) These days I'd classify myself as more of a mechanical engineer/entrepreneur.
While the first version of my laser is going to be a copy of rog's one, I still want to understand everything about everything that's going on so I can refine and make my own design. So while reading up on polarization on wikipedia, the single photon thought popped into my mind and I thought I'd see how others modeled this stuff in their heads, hence my post.
For the record, the very first response (by mixedgas) happens to be pretty much exactly the answer I had in my mind when I posted the question. But as often happens with a good question, the answer(s) often lead to even more questions, and I've had a great time investigating them!
Thank you, tocket, for your Stern-Gerlach link. And Snilton, your youtube diffraction link http://www.youtube.com/watch?v=VDmbdTtcoPM came at a great time, as I was trying to describe that very subject to my girlfriend last night! ;) I've enjoyed all of your responses.