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ArcticMyst Security by Avery

Questions about my first laser

Joined
Feb 12, 2014
Messages
2
Points
0
Hi there,
i'm making my first laser and i need help regarding some stuff
so the laser is an IR 808nm 200mw LD and the driver is this one
i assembled and powered it however it seems not powerful at all (using a camera to see), i checked the current at the driver's output and it is ~90ma @ 2.2v, i tried two power adapters one is 12V 2A though the reading was only ~50ma at the driver's input and the other is a 12V 6A with the same reading on the driver's input and output, what could be the problem? or is it that this LD is just as powerful as this?
also i still haven't put it in a housing and the beam is not focused, could this be the cause to why it seems weak?
other questions:
1.what the third lead on the diode is used for?
2.if i want to power a 520nm green LD can i use the same driver?
3.is there a way to make it pulse at a specific frequency like the IR LED?
 

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Joined
Sep 12, 2007
Messages
9,399
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First connect the TTL+ to 5V. This is a high impedance input, so you can use a resistor divider (from 12V for example) without an issue. TTL- and 12V- can (and in most cases should) be connected. Voltage is not critical - anything between 3.5V and 5V should work. Then adjust the current using one of the blue potentiometers. If one doesn't do anything, try the other one. I highly recommend using a test load for this step.

The third lead can be a case pin which offers a neutral connection to the heat sink. It can also be a photodiode, or not connected to anything at all, and it was easier for the manufacturer to use the same tooling setup as the three-pin design. In your case, my guess would be a photodiode. The photodiode is for light feedback, should you choose to utilize it.

You might be able to power higher Vf diodes with this driver. It's hard to know without having a schematic or at least a picture of the circuit underneath. Use a test load to check.

Yes, the output can be pulsed using the TTL terminals. Any digital signal (probably <10KHz or so) fed into the TTL port will be relayed out of the laser beam. You would need to remove the constant 5V of course.
 
Last edited:
Joined
Feb 12, 2014
Messages
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thanks for the help, i connected the TTL to a 5v and the only thing it does is turn the laser on and off, as for the driver it's this one actually.
i turned the potentiometer to the max but still the laser is not powerful at all
 




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