Would a DC-DC buck converter work as a laser driver?

Disclaimer: Despite having goggle, IR laser still scare the shit out of me so I'll be trigger the laser remotely, from another room and watch it through a full spectrum camera. Then physically unplug the battery pack before entering the laser room. Keep your eye balls guys.

I'm planning to drive a 2.3W laser diode, and this is the spec


Using this DC-DC buck converter to drive the diode. The 2 potentiometer control Voltage and Currents.
Powered by 2x 18650 battery (8.4V input)


So far I've only test using it on a red LED which operate in about the same voltage range. I set the Voltage to 2.2 and leave the current at max (5 Ampere). The LED seems to work alright so far.
I also run a few high powered LED at >3V and also max current. Thing seems to work alright.

Would it work the same for a laser diode? My thinking is that as long as the voltage is right, the diode/LED will only take whatever current it needs and don't have to worry about over current. But I want to hear the opinion from people with more experience

On a side note, on Aliexpress I saw a buyer show case his diode test using a 50W resistor connect to the diode in series.

A laser diode wants a constant current source, not constant voltage. If that will operate in CC mode reliably it might work. I'd really want to see how clean its output is with an oscilloscope before risking an expensive laser diode on it.

It's originally designed as a battery charger, so it is constant current mode supply. Yes, it will work fine for a laser diode
As you can see it has a current limit LED

Hello, are there any updates to this?

It is important to limit the current for the diode. Some DC-DC converters can limit both the current and voltage. The load can then be driven in constant current or constant voltage mode, depending on the adjusted limits and the load.
You should test this with a load resistor first, and measure the voltage and current to make sure it regulates correctly. Check that it really limits the current.

For LEDs and laser diodes, you would want to limit the voltage to a reasonable value (not higher than the max operating voltage), and then drive it in CC mode to set the desired current. Start with low current first and slowly ramp it up. The converter will set the appropriate voltage to keep the current at the setpoint value.



Diodes are very nonlinear loads (which means the resistance changes with voltage), and you will see that a small change of voltage will cause a big change of current. Also the resistance depends on the temperature, usually when they heat up, their resistance drops. And if the voltage is kept the same the current will increase, which could damage the diode. That is why we use drivers for the diodes: to control the current.