Intensity pattern of the emitted light

In summary: Hi,Thanks for replying! However I have to disagree. So B is perp. to k, which is perp. to E: If the electron is oscillating circularly along B, then looking "edge on", it looks linear. And it is exactly this motion that the E-field excites. So the transitions being driven are delta-m = +/- 1.Does this sound reasonable to you?When I find a moment I will work this out in detail.
  • #1
Niles
1,866
0
Hi

I am looking at a bunch of atoms in a homogeneous magnetic field, irridiated by a monochromatic EM wave. I am trying to figure out how to intensity pattern of the emitted light by the atoms looks.

Case 1) I have attached a picture of the situation called "case_1.jpg". It is very clear that only π-transitions are being driven, i.e. Δm=0 transitions.

Case 2) I have attached a picture of the situation again. The quantization axis points along the magnetic field, but the polarization is orthogonal to it. So somehow I need to decompose the polarization into something in the same plane as the B-field. How can I do that?

I would be very happy to receive some feedback.


Niles.
 

Attachments

  • case_1.jpg
    case_1.jpg
    1.6 KB · Views: 561
  • case_2.jpg
    case_2.jpg
    1.6 KB · Views: 585
Physics news on Phys.org
  • #2
Ah, ok. I think I figured it out entirely by myself. I can of course always decompose it into circularly polarized light along k. So they will drive the Δm=+1 and Δm=-1 transition. But then what happens when B is perpendicular to both k and E? Then my "trick" doesn't work anymore.

Niles.
 
Last edited:
  • #3
Niles said:
Ah, ok. I think I figured it out entirely by myself. I can of course always decompose it into circularly polarized light along k. So they will drive the Δm=+1 and Δm=-1 transition. But then what happens when B is perpendicular to both k and E? Then my "trick" doesn't work anymore.




Niles.
Maybe that is a forbidden transition.
Or maybe you better look at quadropole moments, or magnetic dipole moments.
I thought that the m=0 transition is dipole forbidden, anyway.
 
  • #4
Darwin123 said:
Maybe that is a forbidden transition.
Or maybe you better look at quadropole moments, or magnetic dipole moments.
I thought that the m=0 transition is dipole forbidden, anyway.

I'm pretty sure having E perp. to k perp. to B will still yield a signal. I just don't see how I can ever decompose E into something along B, but I know it is possible.
 
  • #5
You can still decompose the linear polarization into two circular ones. What changes wrt case_1 is the relative phase between the two circular waves.

Therefore you should get the same spectrum as in case_1, i.e. delta-m=0.
 
  • #6
Hi

Thanks for replying! However I have to disagree. So B is perp. to k, which is perp. to E: If the electron is oscillating circularly along B, then looking "edge on", it looks linear. And it is exactly this motion that the E-field excites. So the transitions being driven are delta-m = +/- 1.

Does this sound reasonable to you?
 
  • #7
When I find a moment I will work this out in detail.

You can write the dipole operator ε.r as Ʃ_m |r| ε_m Y_1,m
where m=-1,0,1 and Y_1,m is a spherical harmonic.

The matrix element then reduces to an amplitude prefactor and some
Clebsch-Gordans. If you know the initial and final angular momenta
this is easy to write down exactly.
 

1. What is the intensity pattern of the emitted light?

The intensity pattern of the emitted light refers to the distribution of light intensity across the emitted light beam. This can vary depending on the source of the light and the properties of the medium through which the light travels.

2. How is the intensity pattern of the emitted light measured?

The intensity pattern of the emitted light is typically measured using a photodetector, which is a device that converts light into an electrical signal. The intensity is then recorded and plotted to show the distribution of light intensity.

3. What factors affect the intensity pattern of the emitted light?

The intensity pattern of the emitted light can be affected by several factors, such as the wavelength of the light, the properties of the medium through which it travels, and the characteristics of the light source, such as its shape and size.

4. How does the intensity pattern of the emitted light impact the quality of an image?

The intensity pattern of the emitted light can greatly impact the quality of an image, as it determines the contrast and sharpness of the image. A uniform and consistent intensity pattern can result in a clearer and more detailed image, while irregular patterns can lead to distortion and blurriness.

5. Can the intensity pattern of the emitted light be manipulated?

Yes, the intensity pattern of the emitted light can be manipulated through various techniques, such as using lenses and filters to alter the direction and intensity of the light. This can be useful in enhancing the quality of an image or achieving a specific lighting effect.

Similar threads

  • Atomic and Condensed Matter
Replies
6
Views
861
Replies
22
Views
1K
  • Introductory Physics Homework Help
Replies
25
Views
2K
Replies
3
Views
3K
  • Atomic and Condensed Matter
Replies
1
Views
1K
  • Aerospace Engineering
Replies
5
Views
1K
Replies
10
Views
803
Replies
17
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
1K
Back
Top