Laser module recommendations

[eightyninewarren]

Hello everyone,

A few years ago I built an Arduino RS232 optical data link using a green LED TX and phototransistor/amplifier RX. I'd like to get some range into the hundreds of meters, so I'll need a laser. I am looking for a module only (laser+lens) or laser+lens+driver, as the laser itself needs to be wired into the TX circuit.

I'm in Canada, which supposedly recently changed its import laws some years just before the Harper government left power in 2015.

This project will be done at night, so I don't need crazy output power: 20 or 30 mW MAX will do fine, even 5 mW should do. I just need a relatively collimated dot beam like you would get even with a crappy pointer.

Has anyone ordered something like this before? Could you steer me in the right direction? Thanks!

 

[diachi]

One of those cheap red diode modules, a driver with TTL modulation and a beam expander (telescope in reverse) would probably do the job. Might even get by without the expander.

Can likely get most of what you need on eBay.

You'll have no problem importing stuff, especially if it's not a pointer. But even then, you'll have no trouble.

 

[BrilliantLasers]

The best watt per dollar I've found is this unit: https://www.ebay.com/itm/PWM-Blue-L...091452&hash=item3d7fd6be2d:g:ucYAAOSwaJ9cPIRy

The divergence is not very good on this one though. I'm sure a beam expander would make it worthy though.

I'm also Canadian, I've ordered several lasers without trouble. Just don't do anything stupid with them.

 

[diachi]

The best watt per dollar I've found is this unit: https://www.ebay.com/itm/PWM-Blue-L...091452&hash=item3d7fd6be2d:g:ucYAAOSwaJ9cPIRy

The divergence is not very good on this one though. I'm sure a beam expander would make it worthy though.

I'm also Canadian, I've ordered several lasers without trouble. Just don't do anything stupid with them.

Even with a beam expander the divergence isn't going to be great on that. That's listed as 8W, meaning big fat, square, blue beam. OP needs a few 10s of mW at most, not 8,000 (assuming it's as advertised, which is doubtful.). Not sure why you'd even suggest that.

A low power red will provide good divergence for a low price.

 

[BrilliantLasers]

Even with a beam expander the divergence isn't going to be great on that. That's listed as 8W, meaning big fat, square, blue beam. OP needs a few 10s of mW at most, not 8,000 (assuming it's as advertised, which is doubtful.). Not sure why you'd even suggest that.

A low power red will provide good divergence for a low price.

I suggested it solely on the fact that it's a really great deal. I bought it, and I can confirm that it's a beast. I will say that it is unlikely it is reaching 8 watts though. 5-7 watts easily though when comparing to other lasers in the same ball park.

Made a laser gun out of it. Made a video of me killing my old Iphone with it. https://www.youtube.com/watch?v=CeTJgzKbqx0&t=20s

 

[icecruncher]

I suggested it solely on the fact that it's a really great deal. I bought it, and I can confirm that it's a beast. I will say that it is unlikely it is reaching 8 watts though. 5-7 watts easily though when comparing to other lasers in the same ball park.

Made a laser gun out of it. Made a video of me killing my old Iphone with it. https://www.youtube.com/watch?v=CeTJgzKbqx0&t=20s

"Be extremely subtle, even to the point of formlessness."

What you are suggesting is dangerous, overkill and won't work very well for his application.

I personally think the HeNe, although slightly more expensive than a red diode would give better results and be easier to align.

If you really wanted to be subtle about it (discreet), an 808 or 1064 would also work, but would be more difficult on the receiving end to align. However it wouldn't be noticed.