Experimental first build....Now have addiction

Well i am new to this forum and to laser diodes, but I have been silently absorbing information for about a month or so from this forum. The amount of knowledge here is incredible.

I have a decent background in electronics, and I have a tendency to mod any and everything that is capable of being modified. Usually it is firmware, but you get the idea. I'm digressing, but after adjust the pot (hardly a "mod") on a green 5mW ebay pointer from hong kong for some short-lived burning etc., I find myself unable to help myself. Why are lasers so cool? Can anyone explain that? Does anyone even need to explain it?

Now, to the point; after learning a tremendous amount by reading through various threads I had no choice but to order LD's etc. This build was my first, and since I didn't have much to spend, I went for a very crude, rudimentary first build. Was expecting to possibly screw it up on the first try as well. But since I got almost all of my info from this forum I thought I'd contribute a bit by detailing the build and sharing some pics. Maybe this will help someone.

Welcome, Kudos for doing your homework & where is the rest of your post?

As I said, I was going for the bare minimum in terms of bang for buck, and this was a trial run. As a result I chose not to pay the money for a driver. A circuit that I often use for recharging disposable alkaline batteries (yes you read that right) turns out to be just the trick. It is a simple LM317 based current regulator with which I am all too familiar. I set the current with three 10-Ohm resistors connected in parallel (=3.3 Ohms), which comes to approx 375mA. Below the circuit is assembled on a breadboard for testing. The LD has leads soldered directly to the pins, along with a small ceramic disc capacitor to fend off ESD. The leads then attached nicely to the breadboard. A 6-volt lantern battery powers this strange little creature.

Pictures coming, along with other stuff. I need a few minutes cause I'm a human.
Sorry for multiple postings in a row- a bit annoying. I'll see if i can fit most of it in the next.

Take your time

The edit button will allow you to add to your post at any time.

MAN! Browser crashed and i lost several paragraphs with captions. ahhhh
Bear with me.

This is the driver circuit assembled on a breadboard along with a lantern battery.
Note that apparently not all of the resistors are in this pic for some reason.



The housing for the laser is as simple as it gets- 20x red sony diode in Aixiz module. I used a small Dark Horse heatsink and an improvised brass sleeve (leftover from an old 5mW green) along with plenty of arctic silver. I was surprised to learn that the brass sleeve was quite effective. If I didn't already mention this, there is a small ceramic cap across the diode leads to help with ESD.



After testing the whole setup, I soldered the current regulator to a PCB after adding a pot and power switch to the design for adjustment from 27mA to roughly 400mA. Epoxy covers most of the board's components (except the switch and pot obviously) to prevent shorts.



so many edits.....

I'd love to hear opinions/suggestions/tips etc. I'm getting ready to build a few more lasers. I'd like a blu-ray eventually, and I wish I could find a 1/2 watt or bigger diode in a 5.6mm package- if they exist. I am under the impression that IR diodes are cheaper per mW than most of the visible spectrum diodes. This would be perfect for my next build, or the one after it, etc. if I could find such an IR diode less than 900nM (so it will still be slightly visible without using a camera).

My tip would be to give a flex drive/rckstr driver a go, get hold of an aixiz module and a diode and you'll be able to get together a really small little build

If you enjoy the building aspect of the driver, and your good at smd soldering, rckstr drivers to come it kits at modwerx.com

If you want a blu-ray build PHR-803T's put out about 110mW and are very cheap now, about the same as reds. Or if you want to go upto a 6X GGW or SWF diode you can get upto 250mW with the correct lens

As for IR, they are cheaper but the higher end diodes for power tend to be either 9mm or c-mount requiring special optics and a different module to house the diode.

Checkout jayrobs flashlight kits as well with custom heatsinks for your build with an aixiz module

remember the more you read the more you'll learn!

DestonianTheory said:

I'd love to hear opinions/suggestions/tips etc. I'm getting ready to build a few more lasers. I'd like a blu-ray eventually, and I wish I could find a 1/2 watt or bigger diode in a 5.6mm package- if they exist. I am under the impression that IR diodes are cheaper per mW than most of the visible spectrum diodes. This would be perfect for my next build, or the one after it, etc. if I could find such an IR diode less than 900nM (so it will still be slightly visible without using a camera).

Click to expand...

There are plenty of high powered 808nm diodes available. They're slightly visible .

Thanks for the info. As for the homemade driver, i did that just to cut costs down. The main purpose of this build in the first place was practice (among other things) so I could get my feet wet before attempting more costly builds. I'm glad you told me that about rckstr's coming in kits. All surface mount stuff I assume. That might be an option, but that Dr Lava boost convertor driver is pretty impressive. The 5.5 volt max may be a problem with that one in particular though.

As for the 9mm iR diodes you mentioned- i have read that there were 9mm and i think 12mm LD's out there, but I couldn't find out where to get them or what to mount them in. That seems a good option depending on how hard or easy they are to find.

On another note, since I built this little bare-bones unit I have done something else with one of those chinese 200mW red lasers. I will be posting this in the experiments/modifications area.

Nefarious said:

There are plenty of high powered 808nm diodes available. They're slightly visible .

Click to expand...

I've had a bit of trouble finding them. assuming you mean 5.6mm diodes, do you know any good site to buy them from?

DestonianTheory said:

I've had a bit of trouble finding them. assuming you mean 5.6mm diodes, do you know any good site to buy them from?

Click to expand...

Check ebay, or talk to LPF member: heruursciences he sells a lot of diodes and parts