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Help with first build

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jhon57

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I recently bought a TO-18 808nm IR laser diode for 5.8 USD and bought the housing for 4.4 USD. I want to power it using 3 AAA 1.2 Volt rechargeable NiMH cells. I was thinking I could use LM317 and a 3.6 Ohm resistor to get a 347ma constant current source.
I want to know if I'm doing something wrong and if there is a chance of burning my diode before using it.
Also would using a peltier for cooling help increase the life of the diode?
Data sheet attached.
 





diachi

diachi

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Not seeing the attached datasheet.

Do you have any experience with lasers >5mW?
 
J

jhon57

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No I don't have any experience with lasers of power >5mw. I think the datasheet should be there now. I had some issues because I'm posting from android.
 

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  • WSLD-808-300m-1-PD.pdf
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WizardG

WizardG

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You are aware that 808nm isn't really a visible wavelength, right? To my eyes 1 watt of 808nm as a very dim spot on a white wall.

Before you solder anything together get some safety goggles.
 
diachi

diachi

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jhon57 said:
No I don't have any experience with lasers of power >5mw. I think the datasheet should be there now. I had some issues because I'm posting from android.
Click to expand...

I'd advise against 808nm as your first high power laser as it's practically invisible. Easier to get a feel for things with visible first.

That said, yes, an LM317 set up for constant current is what you want. 347mA is almost exactly the specified drive current, that'll be fine.

No need for a TEC, just use a decent sized heatsink for the module and you'll be fine, with forced air if passive cooling isn't enough. This LD won't produce a ton of heat.

If you decide to go with 808nm, proper safety glasses for 808nm are an absolutely must. 300mW at 808nm can instantly do permanent damage to your eyes, and you may not even notice it until a spot shows up in your vision.

WizardG said:
You are aware that 808nm isn't really a visible wavelength, right? To my eyes 1 watt of 808nm as a very dim spot on a white wall.

Before you solder anything together get some safety goggles.
Click to expand...


Yup, ~17W (17,000mW) at 808nm is dimmer than 1mW of 650nm to me.
 
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paul1598419

paul1598419

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Yeah,I don't know why you would want this to be your first laser build. I have a 1 watt and it looks like a dim red spot on a white wall in a dark room. I actually have an IR camera to set focus on it. They make cheap drivers for this diode that can be had on eBay for less than $4.00 shipped. A better choice for your first built would be an LPC 826, 836, 840. These are 650 nm to 660 nm and can be driven to 400 mW quite easily. They are all single mode diodes so you have great beam specs and the color is a pure red.
 
RedCowboy

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Get a 200-400mw 650nm and use your 317, you can focus it to burn paper and it makes a very pretty red beam at night and just beautiful in the rain and fog.

The problem with 808nm is you can't see it, not hardly, yet it penetrates the human eye's lens as visible light does striking the retina, so you could be doing terrible lifelong damage and not even know it until you realize your blindness.

Unless you have a very specific purpose for using 808nm then do yourself a favor and don't.

The beam quality of the 660-650nm diodes is so much better.

CLICK >>>>> mitsubishi 650nm red laser diode | eBay
 
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jhon57

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I know that IR is not visible. But the thing is that I want to make a mechanism to set off fireworks from 10 m away without people realizing how the fireworks are being lit. The beam is going to be parralel to the ground and about 4-5 cm above it. I'm going to be wearing a gear VR while operating the laser so that I can see the beam. And the beam is going to terminate at a rock that is going to be fixed to the groung about 2 m from the fireworks.
 
diachi

diachi

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jhon57 said:
I know that IR is not visible. But the thing is that I want to make a mechanism to set off fireworks from 10 m away without people realizing how the fireworks are being lit. The beam is going to be parralel to the ground and about 4-5 cm above it. I'm going to be wearing a gear VR while operating the laser so that I can see the beam. And the beam is going to terminate at a rock that is going to be fixed to the groung about 2 m from the fireworks.
Click to expand...


So no one else in the area will have eye protection? :thinking::thinking:

Disregarding the safety issues for a minute, that's going to be difficult anyway, you'll have a hard time lighting a fuse at that distance with that power.
 
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lasersbee

lasersbee

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jhon57 said:
I know that IR is not visible. But the thing is that I want to make a mechanism to set off fireworks from 10 m away without people realizing how the fireworks are being lit. The beam is going to be parralel to the ground and about 4-5 cm above it. I'm going to be wearing a gear VR while operating the laser so that I can see the beam. And the beam is going to terminate at a rock that is going to be fixed to the groung about 2 m from the fireworks.
Click to expand...

You have a problem Huston....

Mainly because you can't see the 300mW INVISIBLE 808nm beam
at that distance let alone hit a small target like a fuse at 10 meters.

Like everyone suggested above...
For your own safety I would suggest a VISIBLE Laser wavelength
for your first build and to test out your mechanism...

Jerry
 
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Alien Laser

Alien Laser

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why not use 405nm the 808nm is invisible you will not be able to see it at the distance ,in the video is a 1500mW can barley see it
Safely is imported for you and the people around you :)
 
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E

Encap

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jhon57 said:
I know that IR is not visible. But the thing is that I want to make a mechanism to set off fireworks from 10 m away without people realizing how the fireworks are being lit. The beam is going to be parralel to the ground and about 4-5 cm above it. I'm going to be wearing a gear VR while operating the laser so that I can see the beam. And the beam is going to terminate at a rock that is going to be fixed to the groung about 2 m from the fireworks.
Click to expand...

What everyone else has said above, especially safety --you need laser goggles while you are working on it and testing it.

You did not mention how you were going to focus the 808nm output + even a focused 300mW of 808nm is not going to burn or set off anything at 10 meters away.

Watch this guy struggle to melt black electrical tape at 3 inches with a 300mW 808nm: https://www.youtube.com/watch?v=3eysyhdsQIk
 
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