All Questions
12
questions
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43
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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
1
answer
79
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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
3
votes
1
answer
1k
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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
0
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0
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49
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How to explain light beams in terms of wave theory?
How can we explain the formation of light beams in terms of wave theory?
According to wave theory, shouldn't the source point of beams emit radiation omnidirectionally, rather than a concentrated ...
- 533
0
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0
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169
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Infinite universe and the impossibility of monochromatic light and infinite plane waves
I recently asked a question relating to this excerpt from the textbook Optics, fifth edition, by Hecht:
Mathematically, the plane wave extends out to infinity in all its directions, and, of course, ...
- 889
-1
votes
1
answer
42
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Laser emission frequencies: does that physically represent the frequencies if it was turned on for infinite time?
Consider you have a laser that has a given emission spectrum.
Does this emission spectrum physically represents the electromagnetic field it would emit if it was turned on for an infinite amount of ...
- 1,450
1
vote
1
answer
455
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Confused about intensity of a laser beam
For normal natural light coming from the sun, the electromagnetic waves emanate from the sun with a spherical wavefront, then we can calculate the intensity of these waves reaching us on Earth by $ I =...
- 753
1
vote
1
answer
1k
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mode-locked laser Repetition Rate
I don't understand how we can produce a laser system with different (lower) repetition rate than the resonant frequency of the cavity?
In other words, when we have different resonating modes, then ...
- 161
11
votes
3
answers
838
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Are non-zero-area pulses of electromagnetic radiation possible?
This is a bit of a long-standing question / bone of contention that I've seen floating around, and which I would like to ask here in the hopes of getting some outside perspectives from a broader ...
- 134k
1
vote
1
answer
1k
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Amplitude of E-M wave (e.g. laser) in meters?
The wavelength of an electromagnetic wave is described in terms of distance (e.g. 633 nm). I understand this physically as the distance over which the repeating peak to peak oscillations occur.
I am ...
- 394
5
votes
3
answers
45k
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What is the amplitude of the electric field in a laser?
I'm looking for reliable informations about the amplitude (not the intensity), in volt/meter, of the electric field in a typical laser.
Or in other words : what are the typical amplitudes of the ...
- 7,592
2
votes
1
answer
3k
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How to calculate loss due to Gaussian beam divergence of a laser going through multiple lenses?
To better explain my question, I will need to give a brief description of the configuration used in 2D MEMS switches.
So, the next figure shows a configuration of a 2D MEMS switch, a light beam ...
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