Take a few of my favourite subjects: quantum dots, satellites, and gold. Mix them together, and what do you get? A breakthrough from Rensselaer Polytechnic Institute that could revolutionise infrared detection. Somewhere, the Predator is jealous.
What the RPI researchers have managed to do—increase detectivity in quantum dot-based IR detectors 20 times over—is particularly remarkable in that they're able to greatly enhance the signal of the detector without also increasing the noise. They've done it by creating a "microlens," that uses nanoscale gold to push light into tiny holes on the surface of the device:
The surface plasmon QDIPs are long, flat structures with countless tiny holes on the surface. The solid surface of the structure... is covered with about 50 nanometers – or 50 billionths of a meter – of gold. Each hole is about 1.6 microns – or 1.6 millionths of a meter – in diameter, and 1 micron deep. The holes are filled with quantum dots, which are nanoscale crystals with unique optical and semiconductor properties.
The interesting properties of the QDIP's gold surface help to focus incoming light directly into the microscale holes and effectively concentrate that light in the pool of quantum dots. This concentration strengthens the interaction between the trapped light and the quantum dots, and in turn strengthens the dots' ability to convert those photons into electrons. The end result is that Lin's device creates an electric field up to 400 percent stronger than the raw energy that enters the QDIP.
But don't worry, paranoiacs! This is an infrared satellite, so it's not like those government satellites trained on your house are suddenly going to be looking at the whites of your eyes.
Instead, the use cases here range from better night-vision goggles, improved medical imaging, and advances in IR telescopes. Also: getting the upper hand against a team of commandos lost in the jungles of Central America, and/or Danny Glover. [Rensselaer Polytechnic Institute via PopSci]