Laser modes

[Abray]

I'm still learning about lasers, so I have another question. :-[

What are the different modes of lasers?

So far, I have heard of TEM00, TEM01, and TEM02 (also stuff like near TEM00)

What exactly does TEM stand for, and how can you tell the difference between the modes?

 

[Things]

http://en.wikipedia.org/wiki/Transverse_mode

 

[Spectrum]

i dont really know alot about them but i do know tem00 is desired and sometimes a laser will mode hop (for various reasons) and the different modes make the dot look different

 

[Abray]

Thanks things, that helped ALOT

I now understand what the modes are, but what makes laser mode hop? What determines what mode the laser is in?

 

[Things]

Temperature, battery voltage, crystal quality/alighnment all comptribute.

 

[Abray]

so, the better quality the crystal (how it is set), the voltage, and the temperature all determine the quality of the laser?

basically the better quality (or better monitered or used) laser creates a better quality beam?

so I'm guessing that when people call lasers from oh.... techlasers...mode hopping pieces of junk, it's probably because the heat isn't dissapated properly or the crystal isn't set right.

 

[Things]

Yeb, basically! If its heatsinked well, and uses good batteries, that will result in no mode hopping, as will quality crystals and proper alighnment(The light passes through freely.

 

[joenobody]

Here are a few pics of some TEM Modes happening to one of my lasers. The above link for modes is good info, but I have another laser that when it goes TEM Hopping, the Second Beam Will Spin in a Circular Motion! Something I could not find any info on???
Anyone heard of that or seen it before? Sorry for the fuzzy pics, my camera sucks!
Enjoy!

 

[joenobody]

pic-2

 

[joenobody]

pic-3
If you look closely, it has split 4 times! Notice how off center the beam exits.

 

[Phazonx]

He Joenobody, I'm sure your camera doesn't suck as much as you think it does. Set it to macro mode. Usually a button indicated by a flower icon. thats usually how it it on a digital camera.

take the close up pictures again with macro mode on.