B Experiment issues (electromagnetism)

[Tyler184]

DaveE; I don’t have a laser as of now but I plan to buy one soon for this. I completely agree this is a complex field, I for one, don’t know much in the grand scheme of physics let alone specific niche fields such as optics. I reviewed the three optic phenomenons you linked, and to be quite frank, Pockels effect and Kerrs effect seem to be more complicated than the Faraday effect. Mostly because the math wasn’t linked so I was going purely based off visuals alone and it seemed like it involved a lot of complex geometry which obviously is beyond my scope. Fardays law seems aswell, however the concept makes a bit more sense as it’s more similar to my own experiment. So correct me if I’m correct in my interpretation; the faraday effect is when a linearly polarized light (that is interpreted as a superposition of opposite polarized circular light for our purposes) goes through a transparent medium that has its own magnetic field somehow although I don’t understand how, but it does and the magnetic field of the transparent medium interacts with the em wave such that on the other side there’s a polarity change labeled β; and depending on the specific circular polarity you were observing(left or right), it appeared to move clockwise or counterclockwise.


Regardless if I interpreted it right or not, I feel it’s best for me todo a first experiment getting used to optics then studying theory and improving my experiment from there rather than deeply studying theory and then attempting to make a complex design without prior experience. I’ve done what your describing with my AM radio and it was a complete disaster as I studied a lot of theory without ever having practical experience and making a simple crystal radio proved to be challenging. That’s why for this one I want to try some of the practical stuff people have already done then I study the theory in as much depth as I can understand. From there I will improve the original experiment. Also, for this experiment could I use this optic fiber and this thin film as a polarizer: fiber optic, polarizer. This article says thin film polarizers can polarize lasers which is where I got it from: Link. For future reference I want to try and add photo multipliers to eliminate the need for expensive polarity preserving optic fiber, as, my logic is the sheer numbers of photons could outweigh the ones that are refracted although then again, that might not work.

Dale; good point, if you want I could make a video explaining things? What you offered is a pretty decent idea but I feel with the trajectory this is going (deeper into optics), the idea of simply producing only horizontally or only vertically polarized light without modulating it to carry a specific information could be a bit sidetracked although correct me if I’m wrong as regardless of your background, you still have much more experience and knowledge in this field then me I’m sure.

 

[Dale]

simply producing only horizontally or only vertically polarized light without modulating it to carry a specific information

To be clear, I am not suggesting that you should stop where I did and only do that. I am suggesting you could start there. Then you can modulate/demodulate at that point using whatever polarization modulation scheme you have in mind.

 

[Tyler184]

Dale; oh alright, I suppose I could do that as a start as the parts needed for what you’re proposing is just as a film polarizer and my radio which are some parts I’m gonna use for my experiment anyway. Perhaps I should add a way of observing to ensure the radio signal is polarized. Also, should I make a video as I suggested or is it not needed?

 

[DaveE]

Photomultipliers will convert light to electrons in a circuit. They won't preserve any of the original wave features like polarization.

 

[Tyler184]

DaveE; I would use the photo multiplier before the polarizer. Also will that thin film polarizer and fiber topic work?

 

[berkeman]

DaleE

In fairness, they do look a lot alike...

 

[Tyler184]

Whoops, my apologies I fixed that lol

 

[Dale]

To me making a video seems like a lot of effort. I wouldn't bother.

 

[DaveE]

I would use the photo multiplier before the polarizer.

Then you won't need any optical devices downstream from that. There will be no light left to use for anything. They make electrons; photons in -> electrons out.

Seriously, take a bit of a time out and read about how some of these devices you are suggesting work; at least the basics. A constant stream of posts about a changing experiment design isn't going to get you good answers nor will you make much progress. Stop and study, read and think a bit.

 

[DaveE]

Then you won't need any optical devices downstream from that. There will be no light left to use for anything. They make electrons; photons in -> electrons out.

OK, sorry, some do output light. But ALL optical information is lost. The process is this: a photon is converted to an electron, the electrons are amplified (multiplied), then the electrons might or might not be used to create light (with a phosphor, usually, like an old TV tube) if that's what the user wants.

 

[Baluncore]

The arrangement of a disparate group of physics terms in a paragraph is possible, but to actually connect those things, to make a useful instrument, or an understandable experiment, is extremely unlikely.

This thread seems to be going every-which-way, with no known destination, apart from the original two phase synchronous motor that might, (if the frequency could be made low enough, say below 400 Hz), continuously rotate a compass needle, at 24,000 RPM.

 

[Tyler184]

DaveE; I do research the concepts you guys mention and I mention. Perhaps not to the extent you guys know it but to some extent nonetheless. I made the mistake previously of studying too much AM theory rather than practicality which is why I want to set up this experiment (which the details are mostly finalized I was just making sure with you guys that the equipment I hope to use isn’t faulty), then afterward I will study theory in more depth and modify my experiment or simply start a new one. Also, yes that’s the specific type of photomultiplier I was talking about. ones used in night vision goggles for instance, with a phosphor layer for the amplified electrons to hit. My logic was, before the laser is polarized, I increase the # of photons that are eventually polarized to increase the chances in case some are refracted by interactions with matter.

Baluncore; yes, my experiment consists of quite the diverse group of physics concepts, however, it is a practical experiment that I can begin to understand the practicality of optics then I can begin to study the complex concepts of polarity optics like meta surfaces or faradays effects or other EOM systems. Therefore, it’s not that I won’t get into this stuff it’s just that want to develop some practicality along with an interesting experiment. The experiment so far ISNT meant to modulate radio signals yet as there are limitations to that as you guys mentioned (the ridiculous speed the magnetic needle would have to spin at). I just want to see the change in the polarity of a laser beam. One BIG thing I forgot to say previously when describing my experiment which I sincerely apologize about was this change in polarity of the laser comes from decaying the fully powered varying inductor(unplugging it from the power source). This results in a change in magnetic field strength interacting with the magnetic needle therefore rotating the needle and the polarizer imbedded in it thus, changing polarity (check diagram from my previous posts). That is it….no rf signals yet. From there I will begin studying more complex concepts and decide if I want to continue with my current experiment (that is if it even worked) and perhaps see if I can implement bytes storage for analog signals like pulse code modulation does or I could start a new one that’s more complex using different modulations techniques like EOM which is the main one you guys were talking about. I hoped this cleared some things up! And once again, Im sincerely sorry I forgot to say the actual methodology of the experiment, I thought I already said it somewhere but I guess I didn’t. You guys likely thought I was using rf signals as a first step but that’s a potential next step if this first step works and even then I might move on to replicating a different EOM technique for an experiment rather than adding rf signals.

 

[DaveE]

I do research the concepts you guys mention

That's not apparent to me in your subsequent postings.

My logic was, before the laser is polarized, I increase the # of photons that are eventually polarized to increase the chances in case some are refracted by interactions with matter.

OK then, you are the first person I ever heard suggest that the solution to a laser that isn't powerful enough is to put an image intensifier in front of it.

I hoped this cleared some things up!

Not really. But, no, I don't need another explanation. It sounds like word salad featuring technical terms that you don't really understand yet. I think you will make more progress if you stop typing and either study more or design something. We may be able to help if you have specific technical questions, but this sort of dialog is pretty pointless. It seems to an engineer like me that you want the dialog more than the content. Lots of words, but to steal from Gertrude Stein, "there's no there there".