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18 votes
Accepted

In what sense the laser radiation is monochromatic?

Lasers are monochromatic in the sense that they produce a narrow range of frequencies. The difference between a laser and an ordinary light is the optical cavity. Cavity design is complex. For some ...
  • 31.1k
12 votes

On the (non)linearity of electromagnetism

Maxwell equations are linear... but they are also incomplete - they involve sources (i.e., currents and charges) that cannot be determined from these equations. To really solve Maxwell equations these ...
  • 52.1k
10 votes

On the (non)linearity of electromagnetism

Very strong fields lead to vacuum-polarization, i.e. they "create" matter (at the very least electron-positron pairs). Even well before the creation of "real" particles there will ...
  • 1,198
10 votes

In what sense the laser radiation is monochromatic?

One can consider a given laser as a device consisting of three elements: a gain medium, a pump, and a cavity. The laser cavity acts as a frequency (color) selection element. The only light that is ...
  • 511
8 votes

Why do we cool atoms with laser light opposed to normal light

Doppler shift is not a problem, but the essential element in laser cooling mechanism: the laser frequency is chosen in such a way that it is just below the Doppler shifter natural frequency of the ...
  • 52.1k
5 votes

How many cavity round trips typically occur inside laser resonators?

I'll try to address the direct question asked in the title of this question: "How many cavity round trips typically occur inside laser resonators?" The cavity finesse roughly captures the ...
  • 11.9k
3 votes

What are the mechanism of generation of mode-locked pulsed laser?

At the beginning you say: The key mechanism of mode-locking is the generation of multi-frequencies in the cavity. If I got your thought correctly, then it is not true. The mode-locking is used to ...
  • 511
3 votes

What happens to laser power when resonator cavity length increased?

You've left out a lot of details, like the overall cavity design, how the beam is confined, etc. But think of it this way: Assuming the pump power stays constant, it must contribute to either laser ...
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1 vote
Accepted

Is this an accidental interference pattern?

Yes, this is a sort of interference pattern called a diffraction pattern. Most likely it is caused by the aperture of your laser level.
  • 6,295

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