All Questions
Tagged with electromagnetic-radiation laser
118
questions
11
votes
4
answers
2k
views
Can the laser light, in principle, take any wavelength in the EM spectrum?
Can the laser light, in principle, take any wavelength in the EM spectrum? I don't think there is what prevent this in principle, right?
- 959
0
votes
0
answers
43
views
Spherical laser beam terminology
I am currently seeking the correct terminology for a beam that expands linearly from a fixed point, resulting in its wavefronts forming spherical surfaces. However, the beam does not expand in all ...
- 153
0
votes
2
answers
131
views
Determining Gaussian beam parameters of a laser
The intended output of many lasers in laser scanning is Gaussian. At distance $z$ from the waist, the radius of a Gaussian beam is calculated as
$$w(z) = w_0 \sqrt{1+(z/z_R)^2},$$
where $w_0$ is the ...
- 153
1
vote
1
answer
179
views
Is a neutron deflected sideways by a laser beam?
Is a freely moving neutron deflected sideways when a laser beam is directed at it from the side? It would be great if the question could be considered from the two points of view that the laser beam ...
- 10.6k
0
votes
0
answers
54
views
The Stark-Lo Surdo effect
What does the Stark-Lo Surdo effect consist of in the interaction of the electromagnetic field and the active medium in a laser? I thank those who want to give a clear and concise answer.
In my ...
- 121
2
votes
1
answer
682
views
Why can't we use polychromatic light for making laser?
As far as I have read in my textbooks, we can only use monochromatic light for making a laser. Why can't we use polychromatic one? What if we try to make a laser out of a polychromatic light?
156
votes
1
answer
15k
views
What is an "attosecond pulse", and what can you use it for?
The 2023 Nobel Prize in Physics was announced today, and it was awarded to Pierre Agostini, Ferenc Krausz and Anne L’Huillier, for
“experimental methods that generate attosecond pulses of light for ...
- 134k
0
votes
1
answer
79
views
How can a laser be narrow?
In my understanding, light works as follows: every point in space where there is light, this light works as a point source. When we progress in time, the light spreads out from there in all directions ...
- 1,440
12
votes
2
answers
2k
views
On the (non)linearity of electromagnetism
As a student you are typically told that Maxwell's equations (ME) in vacuum are linear. However, it seems that for extremely high electromagnetic fields the equations for electromagnetism turn out to ...
- 1,211
2
votes
3
answers
266
views
Coherent unpolarized laser light
I notice that in semiclassical treatments of laser light absorption by particles, they treat the laser beam as a coherent oscillating electric field over the form $E_0\cos(kx-\omega t)$, sometimes ...
- 366
2
votes
1
answer
439
views
Laser induced explosion (detonation)
I have a question involving quite the wacky (and silly) hypothetical. It's a part of an ongoing argument I'd like to settle. Of course, I have no background in physics which is why I came here, so I ...
- 21
1
vote
0
answers
57
views
Decoherence of a laser beam via oil emulsion
This is sort of a followup to an earlier question that I posted regarding how to destroy the temporal and/or spatial coherence of a laser beam. It was suggested to me that I could use a rapidly ...
- 366
0
votes
1
answer
101
views
Is there laser operating at megahertz?
I have tried to find a laser with working frequency at megahertz by Google but failed. Is there exist one?
- 1
3
votes
1
answer
1k
views
Is laser light a standing wave?
If I understand it correctly the light waves are standing within the laser cavity as they bounce off the walls. Does that mean they remain standing as they leave the cavity? There is nothing out there ...
- 1,297
2
votes
2
answers
125
views
Is stimulated emission emitted by a rotating classical dipole subject to a resonant oscillating wave beamed?
Consider a dipole, $\pm q$ connected by a rigid rod of length $2L$, spinning around its center in the $x-y$ plane with angular frequency $\omega$, such that the charges follow $\vec{r}_{\pm q}(t) = \...
- 572
1
vote
4
answers
87
views
Seeing trajectory of light
I had gone through a few posts on this topic in this community,however the doubt i have is different from them a bit. There it was said that we do not actually see a laser beam unless they are ...
- 1,179
1
vote
1
answer
75
views
Can fusional nuclear compression theoretically be achieved with a unidirectional compressive force?
In other words, is it theoretically possible to get an energy-profittable nuclear fusion reaction by simply slamming compressive force into some nuclei from a single laser compressing from one ...
- 29
1
vote
1
answer
175
views
Why are pulsed lasers are the main tool used in nonlinear optics applications, instead of CW sources?
Why we often use pulsed lasers for nonlinear optics applications (such as SHG) instead of continuous wave lasers?
- 367
0
votes
1
answer
30
views
How to relate laser pulse characteristics to the degrees of ionization of a target (i.e. how many electrons get removed per atom)?
Say I have a lithium foil as a target for a laser. Li has $3$ protons and $3$ electrons and therefore $3$ degrees of ionization associated with $3$ ionization energies (for removing the first, second ...
- 255
11
votes
1
answer
2k
views
Can a Black Hole be moved by lasers?
I've read that an object colliding with a black hole will move it, as it would any other object. Could a laser continuously fired into a black hole move it?
- 719
1
vote
0
answers
34
views
Why laser pulses are often assumed to have a hyperbolic secant shape [duplicate]
For mathematical simplicity we often assume that the laser pulses have a Gaussian envelope. But many theoretical models still predict hyperbolic secant pulse shapes for the laser. Any particular ...
- 11
1
vote
0
answers
37
views
Role of quantum fluctuation of light in lasers: simple explanation [closed]
Firstly, I am not an expert and have no background in quantum physics and in physics. I am studying laser technology and have found out that the quantum fluctuation of light will be a limitation of ...
- 11
1
vote
1
answer
191
views
Is it possible to “encrypt” laser beams such that they would need to be “decrypted” to be seen?
I was playing a video game that had some guns equipped with laser sights. It had me think if it would be possible to transmit the laser beam in such a way that it is only visible to an observer ...
- 121
1
vote
1
answer
50
views
Idea to Modulate a Laser with a 1/4 Wave Plate
Procedure:
Take a linear polarized red laser beam and send it through a 1/4 wave plate to create elliptically polarized light. Then send this elliptical polarized light through a linear polarized ...
- 4,711
2
votes
1
answer
54
views
Devices for the generation of polarized light
In many papers dealing with the generation of polarized states of light in imaging applications, Photo Elastic Modulators (PEM) is one of the most chosen devices to modulate the polarization of the ...
- 61
0
votes
2
answers
578
views
Is it possible to create a laser in the extremely low frequency radio spectrum?
I have been reading about effort to push lasers into the hard X-Ray and soft Gamma Ray range, been quoted as one of the most important problems in physics according to Vitaly Ginzburg.
However, would ...
- 477
0
votes
1
answer
125
views
How theoretician or experimentalist knows, exactly what is happening in the Laser (He-Ne) gas tube?
Principle of (He-Ne) Laser : Here Helium atoms don’t produce direct laser photons, but instead, the Helium atom is excited by an electric field. Then Helium atoms will collide with Neon atoms while ...
1
vote
2
answers
143
views
Why does increasing radiation frequency produce narrower collimated beams?
In the context of a THz Gaussian beam $(1)$, it is stated:
Terahertz output radiation at higher frequency produced a narrower collimated beam owing
to diffraction effects (...)
What kind of ...
- 753
1
vote
2
answers
106
views
Why do artificial transmissions of coherent EM waves tend to be isotropic at radio frequencies but directional at visible frequencies?
This is a somewhat soft question, and I'm far from an expert on the subject, so it's possible that my premise is factually incorrect.
The practical generation mechanisms for useful real-world coherent ...
- 48.4k
0
votes
0
answers
191
views
Modeling Gaussian Beam Focusing
I am trying to model beam focusing using machine learning algorithms in Python with the goal of building a model that learns to focus the beam to the smallest point possible. However, I am lost as to ...
- 131