PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please sub

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I posted this two pages back, although these are designed for 1064nm, they should also work at 532nm as a multiple wavelength for the AR coating, you can check with other members to confirm, but I believe any 1064nm beam expander can also be used at 532nm. Although these are heavy, so that might be a problem unless you are building a laser pointer with a heavy battery end to counter balance it with.

Here's a great price on an otherwise very expensive precision adjustable beam expander. Don't let the 1064nm wavelength AR coating cause you to dismiss these, when coated for 1064nm the AR is also good for 532nm and close enough to 520nm to be used with laser diodes at that wavelength too.

Laser Beam Expander Lens YAG 1064nm 10x for Expander for Laser Engraving Marking | eBay

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Large dichroic disks? Make yellow combining red and green: Point Source Laser Optics Beam Combiner Splitter Used | eBay

and another: http://www.ebay.com/itm/Point-Source-Laser-Optics-Beam-Combiner-Splitter/282122321590

 

[CaliKirk]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Large dichroic disks? Make yellow combining red and green: Point Source Laser Optics Beam Combiner Splitter Used | eBay

and another: Point Source Laser Optics Beam Combiner Splitter | eBay

I'm very curious how they could be incorporated into a build, no space saver there unfortunately. I was looking around for random optics deals probably 3 months ago and I came across those. For the price, it would be cool just to have the second one that's listed, I guess really just as a nice paperweight, lol

Nice find(s), man I wish I had your eb@y searching skills!! :bowdown::bowdown:

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Those round dichro's are fairly large, I was looking at them as a way to combine expanded beams, but why expand the beam before combining? I don't know, but nice plates. I already have a couple of the ones from the second link.

 

[94Z28]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Look at this on eBay New 100 Lumens AAA Stainless Steel Small Mini Stylus Pen Light LED Flashlight BU | eBay

Who's into small stainless pocket hosts? I'm gonna get a couple at only 1.50$ and see if I can fit a LPC-826 in it. Diameter is 13mm it should be a perfect fit or damn close to it

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

CHEAP mirror mounts: 3 Laser Mirrors on Mounts 2 Have Surface Defects 1 on Adjustable Mounts | eBay

 

[paul1598419]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Wow, I could have used that one concave one if it wasn't so badly scratched. Can't make a hologram with that. Dang!

 

[thebouljello]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Fiber Coupled Laser Diode 25W 915nm Checked Verified | eBay Has anyone seen this before? I never worked with IR lasers but it seems powerful for the price.

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I saw that a few days ago, was an interest to me until I saw the atmospheric window for 915nm is very poor, I'm only interested in IR for signaling in the open atmosphere after being expanded so far it isn't a danger to anyone more than 100 feet away. I'm talking BIG lenses.

The auction shows a photo with specs that say the unit is single emitter, and when checking the data sheet (link, below) that statement is also made, but there is additional language which makes me think it isn't single emitter! (see the quote, below):

Link to data sheet: http://www.datasheetlib.com/datasheet/637313/bmu25-975-02-r_avanex-corporation.html

From the above link:

The laser diodes are connected in series to allow for fast current switching. The module includes a feedback protection filter that
protects the laser diodes from harmful fiber laser wavelength feedback light.

OK, but further in the spec's they make reference to the 105μm fiber core, that leads me to believe it is indeed a single emitter.... so confused.

Full five page data sheet: http://www.datasheetlib.com/datasheet/637313/bmu25-975-01-r_avanex-corporation.html#datasheet

Last concern; the seller in Israel states the diode was checked and found to be in "good condition". OK, what does good condition mean to them? Maybe I'm just becoming a grumpy old man and don't trust anything enough, but I went ahead and contacted the seller asking if they put a LPM on it to see if at nominal voltage and current the unit produces 25 watts of output. I probably won't go for it, but if I can confirm the emitter size and it is as small as the fiber, maybe I will. I suppose it is possible to use internal optics to telescope the beam down to fit a smaller fiber diameter than the emitter, but I doubt they would do that in such a small package, but maybe?

 

[thebouljello]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I saw that a few days ago, was an interest to me until I saw the atmospheric window for 915nm is very poor, I'm only interested in IR for signaling in the open atmosphere after being expanded so far it isn't a danger to anyone more than 100 feet away. I'm talking BIG lenses.

The auction shows a photo with specs that say the unit is single emitter, and when checking the data sheet (link, below) that statement is also made, but there is additional language which makes me think it isn't single emitter! (see the quote, below):

Link to data sheet: BMU25-975-02-R Datasheet | DatasheetLib.com

From the above link:



OK, but further in the spec's they make reference to the 105μm fiber core, that leads me to believe it is indeed a single emitter.... so confused.

Full five page data sheet: BMU25-975-01-R Datasheet | DatasheetLib.com

Last concern; the seller in Israel states the diode was checked and found to be in "good condition". OK, what does good condition mean to them? Maybe I'm just becoming a grumpy old man and don't trust anything enough, but I went ahead and contacted the seller asking if they put a LPM on it to see if at nominal voltage and current the unit produces 25 watts of output. I probably won't go for it, but if I can confirm the emitter size and it is as small as the fiber, maybe I will. I suppose it is possible to use internal optics to telescope the beam down to fit a smaller fiber diameter than the emitter, but I doubt they would do that in such a small package, but maybe?

Thanks for the reply. I'm not sure how accurate the datasheet is regarding the 25W power output and fiber diameter.

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

If you want both, don't worry, make him an offer.

 

[Cyparagon]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

...after being expanded so far it isn't a danger to anyone more than 100 feet away. I'm talking BIG lenses.

After a certain point, you should switch to mirrors for your final collimation stage. Lenses don't make much sense larger than a few inches.

 

[RedCowboy]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

How does that work? I know how a parabolic mirror can focus to a point but how could I use mirrors?

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

After a certain point, you should switch to mirrors for your final collimation stage. Lenses don't make much sense larger than a few inches.

From the perspective of weight, let alone cost, about six inches is the cut-off for me, after that diameter I believe parabolic mirrors are better. I have a few large PCX lenses, 9, 10, 11 and 12 inches but all of them are too darn heavy for a hand held beam expander. Parabolic mirrors made for telescopes are cheaper for larger diameters, have better surface accuracy when large and can be lower weight with great spot on focus for multiple wavelengths where refractive lenses must be achromatic to do so.

RedCowBoy, from what I've found searching the net, a parabolic mirror focuses the same way a refractive lens does, just move the source closer or further way like a normal lens and it will do the same thing. Only drawback is the source needs to either come through a hole in the middle of the mirror from behind to a sub-reflector, or hang in front of the mirror. Either way, the center of the beam is obstructed some. I suppose you could get an offset parabolic mirror and go in from the side. The satellite dishes I work on are designed that way.

 

[diachi]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

CHEAP mirror mounts: 3 Laser Mirrors on Mounts 2 Have Surface Defects 1 on Adjustable Mounts | eBay

Cheap because they aren't exactly good mounts...

But yes, you are correct regarding parabolic reflectors - there's a reason telescopes are all reflector telescopes above a certain size. Same principle as satellite dishes, as you already know. Talking of which, you could try out a regular off the shelf reflector telescope as a beam expander! Or just build your own...

Now for some laser p0rn (Apparently the correct spelling is censored...)...

A big TEA CO2 laser reflecting off of a parabolic mirror, focusing to a point and ionizing the air at the focal point:

The guy that set that up was looking into a CO2 pumped dye laser - but the idea wasn't to pump the dye with 10.6um directly, instead he'd use the light produced by laser induced air breakdown to pump the dye.

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Cheap because they aren't exactly good mounts...

But yes, you are correct regarding parabolic reflectors - there's a reason telescopes are all reflector telescopes above a certain size. Same principle as satellite dishes, as you already know. Talking of which, you could try out a regular off the shelf reflector telescope as a beam expander! Or just build your own...

Now for some laser p0rn (Apparently the correct spelling is censored...)...

A big TEA CO2 laser reflecting off of a parabolic mirror, focusing to a point and ionizing the air at the focal point:

The guy that set that up was looking into a CO2 pumped dye laser - but the idea wasn't to pump the dye with 10.6um directly, instead he'd use the light produced by laser induced air breakdown to pump the dye.

That is very cool, I was just watching a 3D "holographic" you tube video of a laser which could produce patterns of spots in the air using ionization. Yes, an off the shelf astronomical mirror telescope is the most accurate and cost effective way to have a large diameter beam expander, I can easily afford up to 12 inches diameter using a Dobsonian type of telescope and then it could double as another toy for me, to look at the stars with, imagine that!