Single Mode Laser Diodes

[MikeSD]

Anyone have an example of a laser pointer they have made, that uses a single mode diode, to produce a circular spot.

Is it possible to make a handheld class 4 laser using a single mode diode?

What diode did you use?

I'm curious what the build might be like, since most here are using multi mode diodes.

Thanks,

 

[RedCowboy]

Have you tried the search button?
Only diode that gets close to 1w single mode is the BDR-209, it's a 405nm diode from a blue ray writer.

There may be some super expensive exotics, also dpss is single mode, well tem00 is the target mode, but it's the same for practical purposes.

p.s. Before you mess around with any laser over 5mw you need laser safety glasses that attenuate the wavelength you are working with. That's the most important thing you will buy, your eyesight insurance.

 

[Alaskan]

VG? Is that you? Now I suspect every new member, lol... OK, what color of single mode do you want to build? I have red, green and blue single mode diodes and none of them put out a round dot, but at the same time, they can be focused tight enough to look like they are round and have a low enough divergence they don't spread out into a large fan or rake like a multimode diode does.

 

[Alaskan]

Single mode diodes do not produce impressive beams, they are weak in my opinion, but at the same time, they can deliver more power in a tighter spot at a distance than a multimode diode at ten times the power can do, using the same diameter collimation lens, of course.

I always regret it when I neg someone, I negged him about 2 weeks ago and then put it back.

 

[Alaskan]

Too big, too heavy, too weak.... No perfect solution!

 

[MikeSD]

Have you tried the search button?
Only diode that gets close to 1w single mode is the BDR-209, it's a 405nm diode from a blue ray writer.

There may be some super expensive exotics, also dpss is single mode, well tem00 is the target mode, but it's the same for practical purposes.

Yes, google is my friend. I found a 1W diode for $290

But the point of my post was to SEE what others have done, as I stated in my first sentence.

p.s. Before you mess around with any laser over 5mw you need laser safety glasses that attenuate the wavelength you are working with. That's the most important thing you will buy, your eyesight insurance.

I do already. Have multiple of safety glasses going into far infrared. One is

* 190-540nm
* 800-1700nm

The other is OD4 and covers 190-540nm

Probably shouldn't assume. I'm an Electrical Engineer with 40+ years experience in design. Just not in laser. Just looking to save some time, by seeing what others have done.

Single mode diodes do not produce impressive beams, they are weak in my opinion, but at the same time, they can deliver more power in a tighter spot at a distance than a multimode diode at ten times the power can do, using the same diameter collimation lens, of course.

I guess I should have stated why, although I don't think it's really relevant to what I asked. I'm looking to eventually make an IR laser to be used as a sighting device (firearm use). a 10 foot wide line doesn't make a very good sighting device, at 500 meters. But that's the why. I'll probably buy some commercial laser sight and strip the insides and boost it to higher power. That way, I can get distance and have a way to adjust the beam. But right now, Just looking at options.

 

[Pman]

Just ordered a bunch of single modes. Have plenty class 4 things although theres a few 16x 405nm coming too. Time for seeing really great divergence. A bunch more pen builds coming. Almost done building a PLP520b1 in a special CNI pen host.

 

[H2Oxide]

You'd be hard-pressed to find a single mode diode that outputs a ton of power. Most of the people on here still go by the "old" laser class system, so anything >500mW is class IV.

However, DPSS lasers can have very high outputs and good beam quality, mostly due to the fact that you can pump more power into the crystal and not necessarily change the mode.

It is possible to cram a 1W DPSS into a handheld, and if you're going for beam quality it's definitely the way to go.

Also, technically "far IR" is anything from 15 µm to 1 mm. 1700 nm is still NIR/SWIR.

 

[Pman]

You found what 1W diode?

 

[Pi R Squared]

You don't pay $290 for just any 1W diode. Only 2 of the lasers that I have built are single mode and one of them is class 4:

http://laserpointerforums.com/f45/pl520-build-1-3-lasers-very-pic-heavy-88336.html#top

http://laserpointerforums.com/f38/s06j-12x-build-2-3-lasers-very-pic-heavy-89098.html#post1296670

Alan

 

[RedCowboy]

Yes, google is my friend. I found a 1W diode for $290

But the point of my post was to SEE what others have done, as I stated in my first sentence.



I do already. Have multiple of safety glasses going into far infrared. One is

* 190-540nm
* 800-1700nm

The other is OD4 and covers 190-540nm

Probably shouldn't assume. I'm an Electrical Engineer with 40+ years experience in design. Just not in laser. Just looking to save some time, by seeing what others have done.


I guess I should have stated why, although I don't think it's really relevant to what I asked.

Oh dude, it has nothing to do with assumption, I will preach safety to a career safety instructor until I know who he is, besides if anyone reading this sees what we have said it's just good all around, at the risk of insulting I will preach safety first, every time without knowing or asking, just to say it again and again, it's really that important.

 

[MikeSD]

if anyone reading this sees what we have saidt.

You mean "you". I have no problem what others have said. You are not preachy. You are jackassery. I think that is what is obvious in your replies. But no matter. Every forum has them, reputation notwithstanding.

You found what 1W diode?

I found a couple. One was a 405nm on the DTR site, that was listed at single phase and tested to 1.1W, but advertised as 900mW.
I found another on another site, but didn't bookmark it. I'll see if I can find it again.

Thanks to those who at least took my post seriously.

 

[Alaskan]

Amazing Mike, I'm an engineer too, and also have forty years experience, what are the odds? Hey, I just PM'd you, I can send you a diode to build what you need, just PM back a place to send it to.

You mean "you". I have no problem what others have said. You are not preachy. You are jackassery. I think that is what is obvious in your replies. But no matter. Every forum has them, reputation notwithstanding.

Name calling?

 

[RedCowboy]

My mistake Mike, I thought you were a returning banned member so I was jerking you around, I do preach safety a lot because I think it's important.

I would recommend 1550 diodes to be eye safe and use a ccd to view with a phosphor coated lens, our military uses IR targeting every day, but it's going eye safe now, and getting away from 808 and 910nm. They laze targets at night and only they can see the dot via their night vision.

They are available on ebay, you don't need all that much power, you must have seen them.

Apparently the 808nm-910nm being an eye hazard are getting pinched by the alphabet agency that monitors our GMO fed cows.

 

[Alaskan]

A 1500-1550nm diode isn't any good for CCD, they can't see that low.

 

[RedCowboy]

Yea they use a phosphor coating to view 1550nm with ccd's, the gen 4 night vision is simply amazing, they will put thermal in with it next all in one package, likely already have incoming image splitter to divert to thermal and nv, possibly to display in overlay, if it's not in field it will be, that both are stand alone right now.

http://www.edmundoptics.com/lasers/...ution-1550nm-converter-for-ccd-cameras/2418/#!