1
vote
1answer
45 views

Waveguides Transmission Mode Determination

How do I know if I have TE, TM, or TEM rectangular conductive waveguide? For instance, I am doing a lab where we want maximum magnetic field in the waveguide, does that mean we want the TE because ...
1
vote
0answers
47 views

Do I understand measurement of dispersion relation in a solid correctly?

I'm currently doing an introduction to solid state physics course and have a quick question about measurement of the dispersion relation of phonons in a solid: The way I understood it is the ...
0
votes
0answers
45 views

Has advanced radiation been detected experimentally?

I would like to know whether there has been an experimental detection of advanced radiation. I seem to recall reading about such an experiment but I can't find any reference to it on the interwebs so ...
3
votes
2answers
161 views

Impossible microwave interference?

I was doing a microwave experiment with the following set up: there is a Gunn diode which emmits microwave radiation and a receiver (both work with polarised light). The strange thing is that when ...
3
votes
2answers
301 views

Electromagnetic Momentum

My book says : The fact that electromagnetic radiation of energy carried momentum was known from classical theory and from the experiments of Nichols and Hull in 1903. This relation is also consistent ...
-5
votes
1answer
175 views

home made atom destruction unit [closed]

Today we learnt at school that atoms can be destructed. I believe Physics is a great science to do experiment and I would like to try it at home. Could you tell me what I need to do it? and is it ...
2
votes
1answer
55 views

How does an optic-mechanical laser read and send binary bytes to a CPU?

Thid greatly concerns physics, since a more refined version of my title will be rehearsed below: How is the physical structure of the mechanical eye use a laser to read binary bits held on an optical ...
1
vote
1answer
105 views

william herschel discovering infrared problem

when william herschel conducted the experiment of separating white light with a prism and measuring the different colors, he put a thermometer past the red color as a control finding it to pick up the ...
4
votes
3answers
273 views

Does light really “travel”?

From what I've so far understood about light, a photon is emitted somewhere and after some time it's absorbed somewhere else. Have we had experiments that confirm the path taken or something akin to ...
3
votes
1answer
70 views

Single electron non-perturbing detector

I am designing an experiment where I need to trigger the release of an electron by a radioactive source (Sr-90). The easy way to do it is to use a thin scintillator right after the source collimator. ...
3
votes
3answers
522 views

Magnetic fields and gravitational waves. How far do they reach?

I read that magnetic fields perpendicular to a current shoot out and expand all the way to infinity. Additionally a gravitational wave, no matter how small will also expand to infinity at the velocity ...
2
votes
2answers
3k views

How does Newton's 2-prism experiment help to explain why light does not get dispersed into 7-colors in a parallel glass slab?

In a real parallel glass slide(with two prisms imagined to be touching each other to form a parallel glass slide), The ray of light should pass through the Z in between without any dispersion or ...
4
votes
4answers
1k views

Efficiencies of Coupling Light into a Fiber

I am in AMO Physics and work a lot with optics. I just wanted to get an idea of what coupling efficiencies one "should" get in a "reasonable time"* by coupling light into a fiber using different ...
2
votes
1answer
245 views

Experimental proof of gravitational redshift of light

Has the gravitational red shift been proven for electromagnetic waves only or also for a single photon?
1
vote
0answers
112 views

What narrow-linewidth laser system runs at 2100nm with 1W of power?

For an experiment at our university we need a laser that runs at about 2.1 μm (about 20nm higher or lower would be fine too. We have found a multitude of lasers that achieve this (typically Thulium- ...
2
votes
2answers
1k views

How do you calculate the intensity of light around the focal point from a focused collimated beam of light?

Problem/Purpose of me asking this question to you people who know more than me: So I'm doing a science project where I'm collimating a beam of light to a focus point in a light medium (water vapor or ...
5
votes
2answers
229 views

What reflective media do laser shows use?

I am having a hard time in finding out what exact light media laser shows use. I am trying to build a laser show myself. I know that the laser light is reflected off these particles in such a way that ...
16
votes
5answers
2k views

Home experiments using wireless LAN or mobile phones about electromagnetism?

Are there any nice experiments using wireless LAN access points or routers or mobile phones to demonstrate physical features of electromagnetic fields, especially em-waves? More precisely I am ...
31
votes
4answers
2k views

Scattering of light by light: experimental status

Scattering of light by light does not occur in the solutions of Maxwell's equations (since they are linear and EM waves obey superposition), but it is a prediction of QED (the most significant Feynman ...