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ArcticMyst Security by Avery

what is TEM00?

L

laserlover

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so i see and hear people talking about TEM00 or TEM01 or TEM02 and TEM03 but i have no idea what it means. i tried looking in the FAQ but i can not find it! am i too stupid to see it directly in front of me or is it not there? if someone could explain what it means i would really appreciate it!

-laserlover
 





daguin

daguin

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laserlover said:
so i see and hear people talking about TEM00 or TEM01 or TEM02 and TEM03 but i have no idea what it means. i tried looking in the FAQ but i can not find it! am i too stupid to see it directly in front of me or is it not there? if someone could explain what it means i would really appreciate it!

-laserlover
Click to expand...

LaserModes.png


Peace,
dave
 
artix

artix

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daguin said:
[quote author=laserlover link=1219609711/0#0 date=1219609711]so i see and hear people talking about TEM00 or TEM01 or TEM02 and TEM03 but i have no idea what it means. i tried looking in the FAQ but i can not find it! am i too stupid to see it directly in front of me or is it not there? if someone could explain what it means i would really appreciate it!

-laserlover
Click to expand...

LaserModes.png


Peace,
dave[/quote]

What does TEM04 look like (Spyder 2 BX)
 
L

laserlover

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so if i look at the dot on the wall and it looks like one of those, that's what TEM mode my laser is?

-laserlover
 
daguin

daguin

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laserlover said:
so if i look at the dot on the wall and it looks like one of those, that's what TEM mode my laser is?
Click to expand...

If it is clearly evident, yes. Sometimes it is necessary to shine the laser through a magnifying glass to "defocus" it a bit to see the TEM mode.

Also remember, it could be "rotated" on center axis from these pictures.

Peace,
dave
 
thesk8nmidget

thesk8nmidget

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yes some times the beam comes out as one of thos and ends up still making adot though so check right out of the laser
 
daguin

daguin

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thesk8nmidget said:
yes some times the beam comes out as one of thos and ends up still making adot though so check right out of the laser
Click to expand...


Also sometimes the mode will change based on temperature changes (usually as the laser warms up) and power input (low or fresh batteries)

Peace,
dave
 
C

climbak

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It also depends on the symmetry of the crystals used as well. The above picture is for crystals with a cylindrical shape. There is a whole other set of TEM mode profiles for rectangular crystals. Wikipedia has pictures of both I believe.
 
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b3nault

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So if it doesnt stay in TEM00, does that mean the laser is damaged goods or something?
 
E

ElektroFreak

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Depends on the laser. Mode-hopping is common with pointers due to the small package being unable to deal with the heat generated. In lower powered green lasers I consider it a defect no matter what, but with blue and yellow DPSS lasers it's nearly unavoidable under certain conditions. Also, there are many lasers that are intended to be multimode, particularly high-powered systems. The more modes, the more power.
 
Last edited:
aryntha

aryntha

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Yes, I have a multimode HeNe, the net result is higher power out of a shorter tube, but worse divergence... But, it was designed that way.

I believe Dave has a "photon cannon" of a multimode HeNe himself. I'd like to see some beamshots from that one; and I wonder what it was used for originally. :)
 
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