[Bored chemist]

It will become part of training data for future AI models.

What could possibly go wrong?


campfire tent.jpg (78.37 kB . 744x425 - viewed 1022 times)

[hamdani yusuf (OP)]

https://www.repairfaq.org/sam/onebrewt.htm
I wondered where the light reflected by Brewster window goes.


I'd like to see the demonstrations of this tandem setup. Can it show destructive and constructive interference?

[hamdani yusuf (OP)]

It will become part of training data for future AI models.

What could possibly go wrong?

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A lot. That's why AI safety becomes important.
Just like kids, AI models make mistakes, especially with incomplete data. But with lenough essons learned they can grow up to be more knowledgeable than their teachers.

[Bored chemist]

I wondered where the light reflected by Brewster window goes.

Did you wonder why they are called "Brewster windows"?

"Brewster's angle (also known as the polarization angle) is an angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface, with no reflection."
From
https://en.wikipedia.org/wiki/Brewster%27s_angle

[Bored chemist]

Can it show destructive and constructive interference?

Yes.
Longitudinal Modes
https://www.experimental-engineering.co.uk/helium-neon-lasers/theory-modes-coherence/

[hamdani yusuf (OP)]

I wondered where the light reflected by Brewster window goes.

Did you wonder why they are called "Brewster windows"?

"Brewster's angle (also known as the polarization angle) is an angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface, with no reflection."
From
https://en.wikipedia.org/wiki/Brewster%27s_angle

Let's compare our sources.

https://www.rp-photonics.com/brewster_windows.html
Brewster Windows
Definition: transparent plates which are oriented at Brewster's angle such that parasitic reflection losses are minimized.

An uncoated glass plate at normal incidence would normally have a reflectivity of several percent on each side. With an anti-reflection coating, this could be reduced to e.g. 0.2%. Brewster windows can have at least 10 times lower losses. In addition, any residual reflection will leave the resonator, rather than lead to interference effects (as can occur for windows with normal incidence). Of course, both Brewster windows in a setup as shown above must have exactly the same orientation.

Due to the significant loss difference between p and s polarization, the polarization of laser emission is usually forced to be in the p direction if a Brewster window or Brewster plate is within the laser resonator. In many lasers, this is the only effect determining the polarization direction.

A potential disadvantage of Brewster windows (or other polarizing optical elements) in a laser resonator is that large depolarization loss can arise if, e.g., thermal effects within a laser crystal affect the polarization. In that case, reflected beams with significant optical power and typically poor beam quality leave the Brewster windows.

As usual, perfect material are not common in nature.
The diagrams above clearly show where the light reflected by Brewster window goes.

[Bored chemist]

Light with the "wrong" polarisation is reflected out of the optical path and hits the casing of the laser (or of the lab, if you are running the laser without a case).
But, because it's lost from the laser it isn't amplified (much), so it's not a laser beam- it's just an expensive neon lamp.
The refractive index, and thus the Brewster angle depend on wavelength, so it may be possible to select the wavelength at which the laser operates by changing the window angle..
Obviously, that takes a more complex setup.

[hamdani yusuf (OP)]

2025 world's strongest handheld laser

0:00 intro
3:36 building the laser
6:07 powering it up
7:35 first burning tests
9:58 melting a penny
12:11 opening a bottle
13:38 the Gillette test
15:10 welding with the laser
17:05 making a ruby
19:52 burning tungsten
21:06 burning diamonds
24:05 difficulties and failures
26:22 flammable liquids
28:07 laser vs. ice
29:25 world record comments
32:31 laser safety
33:43 opera sponsored segment

This dude likes to take things to the extreme.

[Bored chemist]

The zinc oxide "frozen smoke" is called "philosopher's wool". It predates manmade lasers.