All Questions
47
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
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
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
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
1
vote
4
answers
86
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
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
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
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
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
1
vote
2
answers
43
views
Area of detectable optical transmission as a function of distance in the context of SETI
The relevant page on SETI's official website states:
The SETI Institute, along with scientists from the University of California's Lick Observatory, UC Santa Cruz, and UC Berkeley has coupled the ...
- 545
0
votes
1
answer
372
views
Why does a shorter-wavelength laser beam diverge less than a longer-wavelength one?
Also, does this phenomenon apply only to lasers, or also to other EM beams?
I wonder if the answer is related to the fact that diffraction limit(s) are proportional to wavelengths...
- 4,509
1
vote
0
answers
72
views
Speckles max intensity paradox
Wikipedia says (link) that in the limit of many interfering waves the distribution of intensities (which go as the square of the vector's length) becomes exponential
$${\textstyle P(I)={\frac {1}{\...
- 11