Quantum rainbow photon gun (quantum rainbow photon gun!)

Shut the windows, lock the doors, and prepare to use your children as human shields, because the Germans have gone and developed a quantum rainbow photon gun. That shoots quantum rainbow photons. EVERYBODY RAINBOW PANIC!

Just a brief word of warning: if you don't want to be a bit disappointed by reality and science explaining just what exactly a quantum rainbow photon gun is, stop reading now and just go on picturing Rainbow Dash holding a laser cannon.

Now, you remember that piece we wrote about the quantum network, right? Well, the security of that network depends on single photons, but generating single photons is tricky. If you accidentally generate any extra photons, you risk compromising everything, since those photons can be used to extract information about your precious precious data.

The secret to this quantum rainbow gun is, as with all things awesome, lasers. A neodymium-doped yttrium aluminium garnet laser shoots a crystal made of lithium niobate to generate a single pair of entangled photons. One of those photons gets sucked up by a detector so that you know that the photons were generated, and the other one is used to transmit whatever information you're trying to transmit.

Oh, and the "rainbow" bit refers to the fact that the gun can generate photons over a range of wavelengths, from about 1020nm to 1120nm, making this rainbow entirely near-infrared, and therefore only visible if you've got a thermal imaging system. This is disappointing, I know, but the key is that the gun is tunable (by heating or cooling the crystal that generates the photons in the first place), meaning that you can optimize the photons to interact with different atoms on the other end.

The Germans (from the Max Planck Institute for the Science of Light) promise to use their quantum rainbow photon gun for good and not evil, or at least, we assume they have, because otherwise, we're all doomed. Eventually, guns like this might end up inside the guts of quantum supercomputers, or as a vital link in ultra secure quantum data transmission.

Paper (PDF), via MIT

For the latest tech stories, follow DVICE on Twitter
at @dvice or find us on Facebook