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What is the temperature of a laser beam ?

brendon7358

brendon7358

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What is the temperature of the photons coming out of a 1W 445nm ? Does anyone know? Or is that just not how it works :thinking: :thanks:

Must remember science class, laser = Light Energy -->Heat Energy ? Is there a formula?
 
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"Heat" is caused by a laser beam hitting a surface and turning from light energy to heat energy. There is no inherent "temperature" to a laser beam, and any assertion of such a measure is generally made by a snake oil salesman. Watch out for any website / person who uses that measure to sell you a laser.

We just measure output power in watts (or, more commonly, milliwatts). :)

Trevor
 
I could be way wrong but I don't see heat as being an energy of a photon, but an energy of interaction with a photon. The beam will heat up things but not because it contains heat. If the total E of a photon is C x planks constant / wavelength, then I don't see any of its energy as heat.
 
No I am wondering because there is a particle simulator kindof game I play and it is possible to make lasers in it but the default photon temp is 922°C it can be heated or cooled I just wanted to know what temp would be most realistic but I guess it does not work that way :undecided:
 
Yeah. Its effectiveness at heating up a material depends more on said material.

Trevor
 
brendon7358 said:
No I am wondering because there is a particle simulator kindof game I play and it is possible to make lasers in it but the default photon temp is 922°C it can be heated or cooled I just wanted to know what temp would be most realistic but I guess it does not work that way :undecided:
Click to expand...

What game?
 
brendon7358 said:
Must remember science class, laser = Light Energy -->Heat Energy ?
Click to expand...

Not enough information is provided. That arrow is a lot more complex than you think it is. It depends on too many other factors to devise a formula that fits all systems.

You begin to realize how ridiculous it is when you carry the implications to other systems :) :

Kerosine has chemical energy. Chemical energy --> heat energy. What is kerosene's temperature?
A projectile has kinetic energy. Kinetic energy --> heat energy. What is a projectile's temperature?
An object on top of a ramp has potential energy. Potential energy --> heat energy. What is this object's temperature?
 
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joeyss said:
Thanks for sharing this thing is really cool...
Click to expand...

If you want to see my "lasers" then type user:Brendon7358 into the search bar :D btw I guess it is a lot more complicated than light --> heat I was just wondering :whistle:
 
I focused my 1W+ 445 laser to a pin point on the tip of a thermal probe and got a max temperature reading around 600 degrees celcius. A laser beam doenst have a temperature, instead, when the beam is absorbed in the form of heat, you can get different temperature readings depending on the object you are aiming at.
 
Think of a ball being thrown against your garage door - it makes a very loud noise...but the ball does not have noise as you throw it..... until it hits the door.;)
The ball KE is converted to noise energy.
ATB
 
Another way to think of it is sunlight; the sun doesn't warm anything up in the shade, yet as soon as you go out into it it warms you right up.

Darker colors also typically warm up faster; hence why most things we burn with lasers are darker colors. It just absorbs more of the photon's energy.

With lower wavelengths though, more energy is absorbed regardless of color... which is why I can burn paper just fine with a 200 mW blu-ray laser, yet it doesn't even so much as smoke with a 200 mW red.
 
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