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View Full Version : Diverging an IR laser

Recurve
06-02-2007, 07:12 PM
Right, as got mentioned in another thread, there are IR lasers on that well known auction site for what seems a not unreasonable sum of money. These lasers however suffer from a rather fatal flaw in the NV illumination stakes, and that is that they only project a dot, in conventional visible light stylee.

So, this has got me thinking, how easy would it be to diverge the beam of the laser in such a way as to make it a half decent illuminator?

My thinking so far is along the lines of using a concave lens to first of all diverge the beam, and then a convex lens to then provide some means of control over the amount of spread. Now I must admit that I am not completely au-fait with laser optics, so this idea may fundamentally fall on it's face.

Anyone got any ideas or further thoughts on the subject?

Cheers, Phil.
Ideot Savant
06-02-2007, 07:14 PM
Whats the mw of the £bay lasers?
Recurve
06-02-2007, 07:19 PM
It's not quoted.
Ideot Savant
06-02-2007, 07:50 PM
If its low then I cant see a point. I've looked at ir lasers and you seem to buy them in about 75mw to about 150.
Recurve
06-02-2007, 08:08 PM
But I thought that lasers were more efficient than their LED counterparts mW for mW?
bennyblanco
06-02-2007, 09:24 PM
i experimented this with a visible laser, it was poo:D

most lasers you will get hold of will be <3mw and although very bright when foccused they dont have the intensity needed to illuminate.



just buy a propper one, they are the ********:)


ben
bingo_beans
07-02-2007, 10:26 AM
A single wavelength light source wont diverge through a lens though will it? Paddy'll be along in a minute and he's much brighter than me.
Recurve
07-02-2007, 03:26 PM
It should do, as it is the action of crossing a glass/air interface that causes the beam to bend. Different wavelengths of light bend by different amounts. The fact that the laser is a single wavelength shouldn't alter the action of bending (after all, they use prisms to steer laser beams round optical tables don't they?
Paddy_SP
08-02-2007, 08:56 AM
A single wavelength light source wont diverge through a lens though will it? Paddy'll be along in a minute and he's much brighter than me.

Must be a different Paddy you're talking about here...:o