How to simulate a Laser Diode ?

[ams09]

Hi all,
This is my first thread here, and I ask your indulgence in advance for my bad English.
Here, I am looking to make a dummy load simulating a laser diode, which can be used in two situations (or more):
1 - Check correct operation of a power supply for diode laser (DPSS)
2 - Make a specific power supply with a diode laser which we know all the features (wine, Vrev, Inom, Ithreshold ... etc.)
I tried dummy loads based on several diodes in series with a resistor to simulate the voltage drop, but the behavior at the current level is not good, it is limited to I = V / R (the R of resitance in series with the diodes)
I stumble a bit on the thing, so if someone can help me at first to work on the 808nm IR diode between 2 and 5 watts.

Thank you in advance to all.
Christophe.

( and thanks to google for is partial translation... )

[mixedgas]

Use a 1R0 or 2R0 resistor and three large silicon diodes in series. The resistor acts as a load and the diodes simulate the voltage drop of the laser diode.

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Steve

[JohnYayas]

Does the laser diode voltage vary with current? I always assumed it stayed constant based on how other diodes work.

[Badpip]

Use a 1R0 or 2R0 resistor and three large silicon diodes in series. The resistor acts as a load and the diodes simulate the voltage drop of the laser diode.

I'd rather say 0R1 for a 5W diode - at 5 or 6A the drop across a 1R resistor will most likely be higher than the supply voltage to the driver.

Does the laser diode voltage vary with current? I always assumed it stayed constant based on how other diodes work.

Yes, it changes with current.

/Thomas

[Xytrell]

Does the laser diode voltage vary with current? I always assumed it stayed constant based on how other diodes work.

It varies for all diodes - just very little. It varies about the same for laser diodes, a few hundred mV.

at 5 or 6A the drop across a 1R resistor will most likely be higher than the supply voltage to the driver.

Also, most resistors don't like 30W of heat

[ams09]

Hi all,

I have some resistors that support 100w and more...
... But a diode behaves as a nonlinear load and its equivalent resistance is very low (approximately 0.25R for a 808nm 2W>5W)

@ Steve: this is the first thing I tried (as said above) but in this configuration for up to 2A it far exceeds 2.2V max allowable by the diode, otherwise it remains to 20mA.

I continue research on my side.

Thanks.

[-bart-]

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Pretty accurate model, except for:
ESD sensitivity
Reversed voltage sensitivity.
Emitting coherent light.

[mixedgas]

Try Shottkey diodes with a low Vf.

Maybe mosfets wired as diode?

Steve

[haze]

I'm trying the dummy load to adjust a cheap driver, but something is wrong ...
I tried 3 different testers, but the reading always remains 20\22mv
the driver works correctly with the connected diode I can adjust the power without problems, but I can't read with the tool ...I'm using some 1n4007 and a 1ohm resistor

this is the driver
https://www.ebay.it/itm/650nm-532nm-...72.m2749.l2649