Is this possible?

[lazerjules]

Hi all,

I have been reading a thread which many of you have probably seen,

http://www.photonlexicon.com/forums/...ght=polarizing

About 2/3rds down the page is a post from Chad (entry 14), his fantastic renders show beam combining method using a circular array of diodes and some optics. This to me seems like a fantastic way to combine beams of single, and multiple wavelengths.

The question is, is this possible? what would the optics be? Some type of positive converging lens, perhaps a plano-convex lens, although would the sources then have to be positioned normal to the surface? Or what about an achromatic lens?

Perhaps someone out there has already tried this, or there is some other reason why this wont work, perhaps it would affect the phase?

Ideas and thoughts anyone?

[Dr Laser]

Beam expander. Keplerian or Galilean. The last one the most popular.

[lazerjules]

Ah, I see....

So, any idea what sort/size, or where from?

Something like the ones in the awesome picture halfway down this laserfreak page, you cant miss it:

http://www.laserfreak.net/forum/view...r=asc&start=50

[Dr Laser]

Arctos? Aaaahhh... They are my heroes

Beam expender.... well you can do it yourself.Or get one premade..
for example http://www.edmundoptics.com/onlineca...productID=2938

X factor to match your needs has to be calculated... by formula.

[Laserfro]

I love the drawing. I think that challenge would be awesome to overcome.

I have always been told that you can not focus a beam further down in size than its original source size. I believe the different diode positions on the 1st optic to be acting like a fat or larger sized beam if you will. I say this because looking at each diode's position, assuming that each is parallel to one another.

What would make this design no different than that of larger beam source?

[krazer]

There are 2 things to consider with this method-
1. You can change the diameter of a laser beam to any (reasonable) diameter, however the smaller the beam the larger the divergence. Ie, a 2:1 beam shrinker will result in twice the divergence.
2. You can't increase the 'brightness' of a laser beam by using optics like that. You can using different lasers and dichroic optics, a PBS and differently polarized sources, or interference based methods (require lasers that are locked to the same frequency, not easy for hobbyists to say the least). You can however put 4 laser beams next to each other (forming a grid), and have a beam that is 4x as large and 4x the power with the same divergence, and then run it through a 2:1 beam shrinker to get a beam that has the same diameter as one of the sources, 4x the power and 2x the divergence. Keep in mind that such a beam will look like an array of spots if examined closely, however for show applications this isn't an issue.