We covered how the speed of light is conditionally constant based on physical medium and we noted that certain materials allow for the illusion that a light pulse is moving faster than light.

Then we have dark light, dark lasers, dark pulses of presumably non-light. Running an electrical current through minuscule quantum dot crystals, causes the crystals to turn into light, projecting a dark light at a particular frequency.

The beams of light are shorter but more stable than the usual sort of lasers, apparently, with the research team claiming that this is because “quantum dots are known for [their] unusual behavior.” Once they emit light, the dots suddenly regain their energy at varying points of extreme quickness. The process is explained like so:

“The new laser depends on the qdots’ unusual energy dynamics, which have the effect of stabilizing dark pulses. After emitting light, qdots recover energy from within rapidly (in about 1 picosecond) but more slowly (in about 200 picoseconds) from energy inputs originating outside the qdots in the laser cavity. This creates a progression of overall energy gains gradually giving way to overall energy losses. Eventually, the laser reaches a steady state of repeated brief intensity dips-a drop of about 70 percent-from the continuous light background.”

It’s pretty complex stuff, but the US National Institute of Standards and Technology, who are working on the research, sees great potential in the dark lasers for “optical atomic ultraclocks and/or superpowered networking and comms kits” in the near future. [Optics Express via The Reg via DVICE]

Around this point my understanding of science, especially energy and light, meets a border.