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collaminated lens and focus lens

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Oct 13, 2009
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Hi all,

What is the difference between collaminated lens and focus lens? Do I need both lenses for a laser diode?
 





"collaminated" ? ..... do you means "collimated" ?

If yes, the lens is not collimated is the beam passing through it that become collimated (or focused) on a certain point.

Basically, "collimation" and "focusing" can be used as synonims, in laser usage (that is a different meaning from a video / photo field of use, but i suppose that you're speaking only about lasers, right ?)
 
ok so collimation lens and focusing lens are both the same?
yes i'm talking about laser only.
 
You posted this on LC aswell I answered it there. However most red diode lasers pointers, portables, DIY's use a single lens for focusing or collimation. In more complex rigs multiple optics are used if you need to have a really good collimated beam (astigmatism correction + expand + collimate). However for most purposes a single lens is enough.

Focusing is just using the lens to focus the beam to a pinpoint/dot. This is used for burning mostly. How focused the beam can be is determined by the die size of the laser diode in this case and the wavelength of the laser... approximately 1/2 wavelength.

To collimate the beam is to have the beam remain parallel with as close to 0 divergence or convergence as possible (it is not possible to have perfect collimation). Also, a wider beam can be better collimated then a narrow one, thus the use of beam expanders for best collimation).
 
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Where can i find a good DIY on collimating a laser? The information i'm most interested in is where to buy the appropriate lenses to make a collimator. I'm fairly certain I can look up the rest and build it from there, but if you have a good reference i'm definitely interested.
 
If you mean a laser diode, any module that is focusable have this possibility (focusing the diode in a beam, you're collimating it ;))

Aixiz modules with diodes, or DIY modules, are selled from some users also in the forum, on ebay, or from some shops (modwerx, o-like, and so on)

Do you want just the module, or the module with a diode pressed, or a complete assembly including the driver ? .....
 
A collimating lens is just that - a lens used for collimating. A focusing lens is just that - a lens used for focusing. The same convex lens at once distance from a diode may be acting as a collimating lens while at another distance it may be acting as a focusing lens.
 
The short answer is both are positive focal length lenses.
Edmund Optics has a very large selection off the shelf of lenses.
 


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