While most mad scientists are off trying to create a laser that can flatten a city in a single pulse, mostly sane researchers at the National Institute of Standards and Technology (NIST), have created one that does just the opposite of the bright-beamed energy weapons of death we've so often imagined – it makes things darker.
This aptly-named "dark laser" doesn't produce short, intense bursts of light that many of us associate with movies, Star Trek, and our fevered imaginations, but instead manages to create repetitive dips in light intensity compared to the continuous light background.
Warning! Science alert!
For those that aren't in the know, a laser is a device which uses "Light Amplification by Stimulated Emission of Radiation" to produce the beams we're all so fond of. Essentially, energy is inputted into what is known as a "gain medium", which contains a substance of any state - solid, liquid, gas, or plasma, but that is of a specific size, shape and concentration. The energy inputted into the medium causes the excitation to higher states of energy of some of the electrons present, resulting in the emission of light. By itself, this is known as an optical amplifier. If this amplifier is then placed inside a resonant optical cavity, a laser can be created.
The dark laser created by the very smart individuals at NIST uses a similar principle, but with a different end result. This laser uses the new technology of quantum dots or "qdots" as its medium, which are nanostructured semiconductors which can be artificiality produced. These dots act much like atoms in traditional mediums, but have fewer drawbacks. When an electrical current is applied to the qdots, they emit light.
Emit light, you say? But this is a dark laser!
When these qdots used by NIST are electrified, they produce light. The then regain energy very quickly from within their own structure, but take far longer absorbing it again from the outside. Slowly, the energy gained by the dots is matched, and then overcome, by energy losses. This in turn produces a reduction in the continuous light background, rather than a jump as is typically observed, and this effect occurs every 2.5 nanoseconds.
Every 2.5 Nanoseconds: Like Clockwork
Sadly, this technology has no use in making people invisible or creating black holes on top of places that we don't like so much. Like Mercury. What has that planet ever done for us? Nothing. It's just hot and all "I'm so close to the sun." Loser.
Instead, the dark laser may have applications in quantum communication, as its pulses are generally less distorted than a typical light laser, and is also being touted as a potential replacement for large lasers currently used in atomic clocks, since the dark laser with its fancy qdots is only about the size of a small computer chip.
So while its not deadly or doomsday-like, the dark laser may have a number of extremely useful applications. It's just too bad world domination isn't one of them.