Host plus beam expanders?

I have a couple 2W blue lasers and I'm thinking of making one with a beam expander. I've been using the survival laser S4 host. I also have one of the stainless hosts. But I'm not aware of any beam expander (5x or 10x) that work with these.

1) Is there a beam expander that will work with either of the Survival Laser hosts? Link?

2) If not, what is a good (available) host/expander combination? Link where I can purchase.

Thanks,
Mike

Hi Mike,

I am not sure if there is a readily available over the counter Beam Expander for that host but are you open to a member here making you one?

Laser Chick said:

Hi Mike,

I am not sure if there is a readily available over the counter Beam Expander for that host but are you open to a member here making you one?

Click to expand...

No objections at all. Not sure how to spec it. I'm just interested in making a blue or green laser, with an expander (adj. preferable) that allows me to have a smaller dot at distance.

If I can get one to fit my existing lasers that would be great (S4 and Stainless Survival hosts), but if not, I'm not opposed to a full custom job. Doesn't have to be fancy.

I'm looking for a 10x for my corrected nubm44, it's beam is 2mm x 4.5mm and slightly negative divergence to about 8 feet, then slowly diverges positive reaching 3.5mm x 10.5mm at 25 feet so it's not rapidly diverging, I would guess about a 60mm objective lens ? Actually as it's negative out of the can a 50mm objective would likely work, but I'm all ears if you have a builder.

I do want it adjustable, and I would like a good price, but I do not have to have it fast so.....I can have 2 out of 3 right?

Good, fast, cheap I can give up fast.

RCB: To expand the output of a corrected beam you will have to use a conventional beam expander, but I don't think you will find one with an output lens that big (~5-6mm input lens too) very cheap, but you can build one fairly cheaply, if you don't need AR coatings using lenses found on ebay, but maybe you will get lucky and find ones with coatings. Hemlock Mike was telling me about a place to get inexpensive lenses which come from Edmunds optics as overstock or sometihing, I think he said Arrow lenses, or optics, but I can't find it through a google search yet.

Just get a 10mm diameter concave lens which has a negative focal length which is 1/10 the positive FL of your 60mm diameter PCX output lens and you are in business, once mounted in a tube. You can get a zoom focuser off of ebay as the focus mechanism, or just machine the tube holding the lens to allow either the input or output lens to slide in or out relative to the other lens.

Here's a link to the type of focuser I bought on ebay for one of my lasers:

2" Ultrawide Double Helical Focuser 0 02mm Scale F Telescope Guider Photography | eBay

I built a beam expander for my NUBM44 diode using one of the above units, here's the thread:

http://laserpointerforums.com/f49/lazy-mans-beam-expander-445nm-nubm44-6-watt-laser-diode-94802.html

Unfortunately, this kind of setup won't work with a corrected beam output, as the G2 lens (3 element, or what have you) must be out of focus, using a cylinder pair requires the beam to be focused to infinity to work. However, you could simply mount a concave lens in front of your cylinder pair and do the same thing.

To do that, I'd recommend finding a surplus 500mm telephoto lens to give more length inside the tube for your long aluminum platform holding the cylinder pairs to fit inside it. I used one of those to build a beam expander, but the iris inside of the one I used might block your aluminum lens platform from passing through far enough, that and the output lens might need to be changed to another one with a shorter focal length. Here's a link to what I built for the uncorrected output of a pointer:

http://laserpointerforums.com/f49/m...photo-lens-converted-beam-expander-95082.html

Eventually, I changed things around on the above project to use a 4 inch diameter PCX lens on the output instead of the one that was in the 500mm telephoto lens. When I did this, the wing splash I had before went completely away, no more wings! But, I couldn't use the full aperture of the collimating lens, only about half, and the beam is in the shape of a rectangle, but it doesn't spread out like a rake anymore, stays that diameter for as far as I can see it travel outward, below:



If I expanded the focus of the G2 lens inside the aixiz module further so the beam would match the diameter of the output collimation lens, then the wings would come back! So, living with a beam that is 2 inches wide, it sure cures the rake or spreading. Seems kinda silly to have a collimating lens which is four inches wide for two inches of beam width, but I don't like the wings so that's the way it will stay, unless I can come up with something to fix the wing issue using the full amount of expansion this lens is otherwise capable of. All of that said, I bet I can eventually find the right 2 inch diameter lens which wouldn't have wings either, if I keep trying, maybe someday I will try. I could have just kept the original lens on the 500mm telephoto assembly and used the iris to clip off the wings too. I don't fully understand what is happening to cause the wing splash, but I've been told it is due to the wide emitter emission of multimode diodes and is astigmatism.

Here's a link to the type of transition cone I used, they used to have a 2 inch diameter input side with a 3 to 4 inch output but right now only have this 1.5" input to 5" output diameter cone: http://www.ebay.com/itm/1-5-5-Trans...nder-6-Tall-Aluminum-JOD-961600-/231708473737 - If you are looking to find some large diameter PCX lenses, search ebay under the term "condenser lens", they often come in an assembly of two, such as this one: http://www.ebay.com/itm/Enlarger-Ru...user-diameter-71mm-2-8-inches-3-/222004843312 - It's a crap shoot what their focal length is, you can buy it and expect the focal length to be from 3 to 6 inches or more, somewhere inbetween those extremes is common for a 70mm lens like this. Sometimes the seller lists the approximate focal length, but not often.

If you buy a lens that is 6 inches or larger diameter, expect the focal length to be 8 inches or more, almost always longer than the lens is wide. For a focal length to be the lens diameter itself the glass is much thicker, so if you see a fat PCX lens, that means the FL is much shorter than a thin one. Here's a aspherical lens with a focal length that is shorter than its diameter, look at how fat this thing is, really thick.... but don't buy this for a beam expander, I already bought one of these from this guy, the glass is crap, even if edmunds, you can see swirls inside the glass, it isn't BK7 glass or even close to that: http://www.ebay.com/itm/Edmund-Scientific-Aspheric-Condenser-PCX-Lens-/380416373436

Here's a round up of my laser pointers with expanded outputs, none of them have corrective optics inside to round out the shape of the beam, so they all output rectangle shaped beams, except the JetLasers 532nm pointer in the far right which is indeed a round output: