Understanding laser diode power consumption.

[thescientist1064]

Hello everyone!

I have a laser diode which generates a 65 W peak power when driven with a 20 A (at 9.5 V) pulse (100 ns, 0.01% duty cycle). Given that the diode is rated for a total electrical power of 20 A x 9.5 V = 190 W, will it draw this much power when operated at a pulsed mode? 

FYI, chat GPT claimed that the current needed would only be 2 mA (= 20 A x duty cycle). So I am confused.

Any help would be greatly appreciated. Thank you!

[Xena E]

Hello everyone!

I have a laser diode which generates a 65 W peak power when driven with a 20 A (at 9.5 V) pulse (100 ns, 0.01% duty cycle). Given that the diode is rated for a total electrical power of 20 A x 9.5 V = 190 W, will it draw this much power when operated at a pulsed mode? 

FYI, chat GPT claimed that the current needed would only be 2 mA (= 20 A x duty cycle). So I am confused.

Any help would be greatly appreciated. Thank you!

2mA is the average current over time. It's irrelevant to the operation of the laser.

The total power consumed over time will be ≈ 19mW.

The PS will still need to be able to pulse the laser at 20A/9.5V. For the rated maximum output power.

Regards,
X

[thescientist1064]

Thank you Xena, for the comment!

Yes, my driver (LDP-V 240-100, manual attached here) is capable of providing up to 240 A pulses.

Its super counterintuitive that the driver only takes in a low electrical power (19 mW) to deliver such a high pulse power (65 W). So if I am understanding it right, I still need a peak current of 20 Amps (at 9.5 V) to drive my diode but the average current drawn from my power supply will be close to 2 mA (20 A x Duty cycle)?

[Xena E]

Yes! You got it.

Making that large current available isn't a great problem of course.

The secret sauce is in the delivery to the laser but that's a well trodden path, and all that's needed is to follow the prior art, and use the components as directed.

A few years back, we used a similar component in a targeting system for a mining application. The emitter was driven almost fully, but the device was powered from a 1604/6F22 disposable battery.