Many hobbies seem to have a subset of participants who just can’t leave well enough alone. Think about hot rodders, who squeeze every bit of power out of engines they can, or PC overclockers, who often go to ridiculous ends to milk the maximum performance from a CPU. And so it goes in the world of lasers, where this avalanche driver module turns Nichia laser diodes into fire-breathing beasts.

OK, that last bit might be a little overstated, but there’s no denying the coolness of what laser jock [Les Wright] has accomplished here. In his endless quest for more optical power, [Les] happened upon a paper describing a simple driver circuit that can dump massive amounts of current into a laser diode to produce far more optical power than they’re designed for. [Les] ran with what few details the paper had and came up with a modified avalanche driver circuit, with a few niceties for easier testing, like accommodation for different avalanche transistors and a way to test laser diodes in addition to the Nichia. He also included an onboard current sensing network, making it easy to hook up a high-speed oscilloscope to monitor the performance of the driver.

For testing, [Les] used a high-voltage supply homebrewed from a Nixie inverter module along with a function generator to provide the pulses. The driver was able to push 80 amps into a Nichia NUBM47 diode for just a few nanoseconds, and when all the numbers were plugged in, the setup produced about 67 watts of optical power. Not one to let such power go to waste, [Les] followed up with some cool experiments in laser range finding and dye laser pumping, which you can check out in the video below. And check out our back catalog of [Les]’ many laser projects, from a sketchy tattoo-removal laser teardown to his acousto-optical filter experiments. Continue reading “Most Powerful Laser Diodes, Now More Powerful” →