low-power 445nm diodes? (5-50mW-like)

[Vickal89]

hey

i am just wondering, if there are any low-powered 445nm Laser diodes, or pen-style Laser pointers existing? Like 5mW or 50mW or something. I only see 400mW or the 1W stuff, but this is too dangerous (and expensive) for me.

But since they have a pretty reasonable $ per Watts price (200$ for 1W for example), low powered diodes must be pretty cheap, or am I wrong?

sorry if this question sounds stupid but I am looking for new Laser colors but i have a pretty low budget, and the 593nm and 473nm DPSS lasers are WAY to expensive for me.

Thanks

 

[AJ_Dual]

These diodes are meant to be run pretty high. And there's not really any price savings because the materials are the same. There are no cheaper 445nm diodes for lower power being produced.

IIRC, at about 200mA of driver current, you might get 5mW out of a 445nm diode harvested from a Casio video projector. Although as it warms up the lasing threshold will change.

I don't think the current crop of 445nm diodes we're all using will be stable at anything less than 20mW, over the eye-safe limit. From what I've read, the diode will "chase it's tail", (get warmer, need more current, get even warmer if you give it that extra current... until it settles in around that minimum range where it's happy.) Lower than that, it'll work intermittently. The upside though is underpowering it certainly won't hurt it.

I could be wrong, maybe people are getting 10mW out of 445 diodes. But I'm pretty sure right at 200mA of current and 5mW of output +/- won't be reliable.

And it'll cost you just as much in terms of diode and driver as a 1000mW build would. If you have a host you plan to use already, that would save you a few bucks, like a suitable LED flashlight, or pen-pointer body you plan to poke the guts out of. So that's why everyone is going high mW with these, because it costs the same either way, so might as well have "more".

 

[leukoplast]

The XJ-A140/130 diodes are the only ones available that I am aware of. LTH is ~200mA on them, which might get you something like 25-35mW IIRC.

I am making a pen style build with a 445 (hopefully tonight). I am using a chrome leadlight style host that I got from Jayrob. It's going to have 65mW output and the current might be somewhere around 275 or 300mA. Both Daguin and Jayrob made lower powered 445's, both run at 275mA. Dave's was 50mW, and Jays was 75mW (cause I think Jay used better optics).

Overall the efficiency of these diodes at lower mW ratings is pretty bad. In fact from the power output to mA input, they are about the same as green lasers. I checked out some O-like green modules the other day, and one that takes in 300mA of current puts out 50mW of green. So I would say any 445nm under 200mW or so is just about as efficient as a DPSS green laser.

Which is sort of good news for pen host builds. Cause I have a 50mW green in a pen host (CNI) and it does just fine. No doubt it has 300mA or so of current (which should emit the same heat as the 445 driven at 300mA I hope). But I will see tonight if I can get it finished. I will be posting pics and overall experiences with my 65mW 445nm pen build.

 

[pullbangdead]

A user named kingstonmeo is selling diodes that will be comfortable at lower powers, but they're actually a little bit more money and more of a pain because they're 3.8mm cans instead of 5.6mm.


"Cost" for hobbyists is a weird thing: we only get reasonable costs when the diodes are being used commonly in consumer electronics. So whichever diodes are being used, those are the ones we get for low prices. In this case, the diodes being used in consumer electronics are the ones you see on here. They'll run at low powers, certainly, you'll just have to see how stable they are in your application.

 

[chipdouglas]

from what i have read, running them lower that 50mw will also give you better beam specs too because it is said to be running in single mode.


michael

 

[Benm]

I'm not sure about that, but it sounds interesting... I'll try so current vs pattern tests at lower currents on these.

Running them at low power will not be that easy though, since you're operating basically just above treshold current, and that depends on temperature strongly.

 

[Vickal89]

thank you for your answers

do anyone here in this forums sell low-power 445nm Lasers in a Pen-host?

 

[leukoplast]

thank you for your answers

do anyone here in this forums sell low-power 445nm Lasers in a Pen-host?

None that I know of, which is why I made my own.

http://laserpointerforums.com/f65/445nm-chrome-leadlight-pen-host-65mw-lots-pics-55026.html