The perfect mirror?

MIT researchers have reported a significant advance in mirror technology, discovering an important aspect of dielectric mirrors that has apparently been overlooked until now. A key feature of the new device, which the researchers have dubbed the perfect mirror, is that it traps light for longer than has previously been possible.

This could open up a myriad of technological and research possibilities. The researchers report that their mirror combines the best characteristics of both metallic and dielectric mirrors. It can reflect light from all angles and polarisations, just like metallic mirrors, but can also be as low-loss as dielectric mirrors. In addition, it can be ‘tuned’ to reflect certain wavelength ranges and transmit the rest of the spectrum.

The work is funded in part by the Defence Advanced Research Agency through the US Army Research Office and by the Air Force Office of Scientific Research.