Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



what are nm?

pullbangdead

Well-known member
Joined
Aug 25, 2007
Messages
2,045
Points
63
Thanks, yeah crest-to-crest, sorry, was thinking wave amplitude. :p

"Beam size doesn't equal wavelength"? But wavelength determines beam-size (diameter at the focal point).
Seems we are going in circles here. :thinking:

My point in simple terms: You can focus a bluray laser to a smaller point than you can a red laser.
-End
But both of those sizes are way smaller than you'll ever actually be able to foces a laser pointer without multiple lenses and much more complicated optics. It's pretty much a completely moot point for a laser pointer, because you're never going to get it that small anyway. For all intents and purposes, that correlation is irrelavent for all but the applications where you have a full optics table and all the knowledge and resources necessary to construct a good optical system.

But I do see what you're trying to say, that a lower wavelength can be focused to a smaller size. But it isn't in any application I've ever seen on this forum, at all. Wavelength can influence beam size, but it won't influence beam size in any application I've ever seen on this forum because a host of other factors will be limiting the minimum beam size to a number a LOT larger than the wavelength of the laser.
 



Ash

New member
Joined
Mar 3, 2009
Messages
2,073
Points
0
but it won't influence beam size in any application I've ever seen on this forum because a host of other factors will be limiting the minimum beam size to a number a LOT larger than the wavelength of the laser.
Now I understand the confusion. ;)
-I am speaking from a "scientific" point of view (facts, real-life comparisons, physics of light).
-While you were reading from a "practical-to-the-hobby" point of view.

No worries. We are both correct. :beer:
 

chipdouglas

Well-known member
Joined
Dec 23, 2008
Messages
4,008
Points
63
ash pbd was the one being scientifical.. he only made his last referrence as a last ditch effort... laser research is litterally his career..

michael
 
Joined
Apr 26, 2010
Messages
4,177
Points
83
A question I've had for a while, can 808nm be frequency doubled to make 404nm?

And +rep for Ash...damn!
 

pullbangdead

Well-known member
Joined
Aug 25, 2007
Messages
2,045
Points
63
Aye aye aye. :rolleyes: I believe I'll leave this one alone with one last post. Thanks you guys there in the last couple posts



A question I've had for a while, can 808nm be frequency doubled to make 404nm?
Yes and no. In theory, high-quality coherent light output at 808nm, with an appropriate non-linear crystal, can be converted to 404nm light. And in theory, there's no difference between theory and practice.

But in practice, 808nm lasers, and really most any diode lasers, are generally not very spectrally pure, and generally have very bad beam characteristics, such as bad divergence. This makes it very difficult, in practice, to directly-double a diode into another wavelength.

It has been done, companies sell commercial lasers that work this way, but it is not very common and is generally very expensive. It's definitely much more difficult than doubling the output of an optically-pumped Nd:YAG laser that was a very "nice" output.
 
Joined
Apr 26, 2010
Messages
4,177
Points
83
Aye aye aye. :rolleyes: I believe I'll leave this one alone with one last post. Thanks you guys there in the last couple posts





Yes and no. In theory, high-quality coherent light output at 808nm, with an appropriate non-linear crystal, can be converted to 404nm light. And in theory, there's no difference between theory and practice.

But in practice, 808nm lasers, and really most any diode lasers, are generally not very spectrally pure, and generally have very bad beam characteristics, such as bad divergence. This makes it very difficult, in practice, to directly-double a diode into another wavelength.

It has been done, companies sell commercial lasers that work this way, but it is not very common and is generally very expensive. It's definitely much more difficult than doubling the output of an optically-pumped Nd:YAG laser that was a very "nice" output.
Thanks a lot for the responce! I figured if it's something not crazy expensive then it'd be on the forums, so I was just curious. I guess I can scratch 1 WATT blu-ray off the list....
 

chipdouglas

Well-known member
Joined
Dec 23, 2008
Messages
4,008
Points
63
actually bloom a 1 watt blu ray is more doable than you think... i haven't seen any body do it, but why couldn't 2- 12x's be combined?


michael.
 

kevinmassey

New member
Joined
Nov 4, 2009
Messages
1,203
Points
0
Last edited:

chipdouglas

Well-known member
Joined
Dec 23, 2008
Messages
4,008
Points
63
yeah i remember that one.... but there is no way a noob or even most vets could pull that off...


michael
 
Joined
Apr 26, 2010
Messages
4,177
Points
83
actually bloom a 1 watt blu ray is more doable than you think... i haven't seen any body do it, but why couldn't 2- 12x's be combined?


michael.

Yeah, but for $500+ I was talking about doing it on a more feasable budget!
 

Tech_Junkie

Banned
Joined
Jan 2, 2009
Messages
11,871
Points
0
yeah i remember that one.... but there is no way a noob or even most vets could pull that off...


michael
I think a few people here could do it. That guy was from PL, and only here to sell that stuff. They laugh at us over there. :whistle:
 

chipdouglas

Well-known member
Joined
Dec 23, 2008
Messages
4,008
Points
63
if i could spell out the sound that your Curley avatar is making i sure would!!!!!


michael
 




Top