Laser Power

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Laser Power

Post by jwax » Wed May 10, 2006 3:48 am

Bought a "Wicked Laser"- 100 mw, red, 650 nm. Yes, very potent!
Topic has been touched on before, but what's the thoughts on pulsing it instead of driving it with continuous 3 volts? Without knowing what the diode max volts rating is, could I get by with say, 6 volts, with a 50-50 duty cycle?
Rather be safe- this "toy" cost over $200! :shock:

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Post by JPKNHTP » Wed May 10, 2006 4:12 am

-God Bless

Michael J
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Post by Michael J » Wed May 10, 2006 8:39 am

A LASER Diode does not work quite like an ordinary LED.
They usually need a constant current to function correctly.
If you didn't get a Specs Sheet on the unit I would be doing
a search on it or similar units and see exactly what supply they
require. As you said they are expensive, would hate to see
one go up in a flash with the wrong supply, would ruin your
morning I would think.

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Post by dyarker » Wed May 10, 2006 8:44 am

Depends on how the laser diode is being driven now. Doubling the input voltage may more than double the current to the laser diode; so 50-50 would still be too much.

Or ...

The current to the laser may stay the same with the driver circuit dropping the increased input voltage.

I'd bet the driver circuit is a little more complicated than just a resistor.

(added: like Michael J said)

Dale Y

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Post by Externet » Wed May 10, 2006 9:22 am

Hey Jwax... if you aim that laser to clouds at night, can you see the glow or dot?
Do you think that power can do cloudwriting, as by rapidly moving the beam?
And do you have a net link for it?
Thanks, :smile:

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Post by haklesup » Wed May 10, 2006 2:15 pm

If you want to increase output, think increasing current not voltage.

Secondly, pulsing might work but better heatsinking would be a way to preserve the diode.

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Post by Chris Smith » Wed May 10, 2006 5:59 pm

Pulsing [CW] laser diodes can damage them, quickly!

The way a diode is modulated is using a inductor into the feed line and varrying the power by about 10% of the over all signal,.... with a induced signal.

Those little green buggers are too expensive to "play with" and from my more than 20 years experience with all types of LDs, I have figured every way to Sunday on how to make toast out of them.

I have done everything from super cooling them and driving them with lots of amps, pulsing them to new limits, and designing dozens of power supplies,........ and one thing that is common and is certain, ......they are sensitive to their PS and they are not forgiving for even a millisecond.

Your main problem would be “over shoot, and Ringingâ€

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Post by jwax » Wed May 10, 2006 6:14 pm

Thanks all. More research needed I see!
No, it will not put a dot on a cloud, several hundred meters yes, but not the thousands of feet of cloud height. Great in fog though!

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