Some of us are anxiously awaiting the photonics revolution, where photons will band together to overthrow the tyranny of electrons. One of the perpetual problems that’s slowing up the revolution is light sources: you need to have a laser that is coupled to a circuit that is going to do something. All of this has to be on a tiny scale that can compete with electronics. It shouldn’t consume much power either.
That’s a hard collection of hurdles to clear. But there is a loophole: a photonic circuit could have the sort of application that electronic devices don’t do very well.
Now, researchers have used that loophole as an excellent excuse to do a very cool experiment in powering lasers. The researchers showed how to power a laser with a laser—something that