New diode laser driver available: FlexMod 1!

[MechEng3]

Great work!!

Do you think it's a good idea to use this driver to replace the one of my Lasever 200mW 532nm (just the diode driver, I'll keep the original driver for the TEC part)? Its analog modulation isn't linear at all, there's a big hole at 3V...

I have had the OC in one of these lasers needing adjustment after some time of operation. One of them needed the Yag moved a bit to get back to the sweet spot. It is most likely in the optics train from what I have seen. Heat and time was the culprit and the one laser may have been jarred rather hard......they are working fine now after the repair was made......but then they are 4 years old too.

[drlava]

PMs Sent to those who expressed interest. thanks!

[carmangary]

I was hoping the diode cathode would be at ground due to prevent possibly blowing diodes when shorting out the case. Robin's driver is the same way. Is there some technical reason why you chose not to design it that way? I'm really curious about that. But regardless, it looks like a nice small driver and I might hit you up for some in the future depending on what I end up doing.

[drlava]

That's a valid point, the technical reason (at least mine) is that for higher power diodes such as c-mount the anode is the case. For fast (500kHz +) switching you want to minimise the path inductance, meaning you usually want to modulate the non-case lead. So, for lower current 5.6mm diodes, the driver has no problem modulating the cathode with a reasonable casing as well. For higher current (more difficult to modulate, more sensitive to inductance) c-mount diodes, the non-casing lead is modulated. Also with the more expensive c-mount, if you short the case it shorts the power supply, and won't kill the diode.

A kind of mirror of the circuit could be devised to do what you desire for 5.6mm diodes, but other than the risk of blowing the diode when you short it, there isn't much reason to do so.

[allthatwhichis]

Would two of these be able to run this... MOPA diode?

[drlava]

that thing's 680nm, so it'll be very dim.. and no, that's a common cathode package (2 diodes, 1 cathode) so you would in fact need 2 anode drivers for that one.

[allthatwhichis]

I actualy have a 660nm or 670nm I got off LaserBen. I want to combine it with a maxyzmodule. I just do not know how to power and modulate it.

[drlava]

you mean one of those melles bricks? they are best used with an upgraded diode. This driver would work well with one of those and I think they are case insulated too.

[allthatwhichis]

No, it is the exact diode that is in the eBay auction that needs two drivers.

[drlava]

maybe you sould make another thread about it then


Have posted a thread that contains photos of scans modulated by this driver:
http://www.photonlexicon.com/forums/...ead.php?t=4620