One device where one rather elegant device is called the kinetic inductance detector and it uses a photon assisted pair braking to affect the detection mechanism. It turns out to be essential to use superconductors in order to be able to make this kind of device. It wouldn't be possible to make a similar device out of normal metals. The reason for this is that the surface impedance of a superconductor is very critically dependent on its temperature, which is not true of a normal metal. Kinetic inductance detector is a thin film device, what one typically has is a superducting transmission line operating at a few gigahertz and this winds its way over the surface of the chip. But then, lightly coupled, in fact, capacitively coupled, side of this line are thin film superconducting resonators. What happens here is that an x-ray comes in, it gets absorbed in the tantalum, it breaks superconducting pairs, it produces a large shower of quasi particles, these get then injected into the resonator, the resonator changes frequency and we can detect the presence of that photon. You can think of this as an effective temperature increase in the material. Well, we're looking at signals from a kinetic inductance detector here. What we can see on the left is a phase shift coming from a kinetic inductance detector as a function of temperature. Inductance detector resonates at a particular frequency at a particular temperature, so by changing the temperature, we can monitor the resonance frequency. These kinetic inductance detectors work at about 20 millikelvin, so extremely cold. Absorption of their photon reflects itself in a change of the surface impedance, which means the microwave properties of the film change and it's those microwave properties which have been read out as the read out circuit of the detector itself. The really exciting thing about this device is that in principle we can hang a large number of resonators off the same transmission line and therefore we can start to build up imaging arrays. Each of the green blocks corresponds to a single antenna and what's happening here is that each of these individual antennas have been read out by a transmission line which winds its way all the way around the outside. Ambition is to build imaging arrays which perhaps have many thousands of pixels and then eventually we would put a chip like this in the focal plane of a telescope for the purposes of making images of astronomical sources. The terrahurt's frequency range has lots of important characteristics that it may be used therefore for utilitarian purposes, the things that will affect our everyday lives. There are an exceedingly large number of applications from associated with medical imaging, industrial process control, dentistry or all sorts of topics and you'll see over the next 20 years you'll see this grow, you'll see that terrahurt's cameras, terrahurt's instruments starting to be commonplace in the world around us. One example of this is in imaging for security applications. It turns out that terrahurt's radiation passes through materials like plastics and fabrics really rather easily but of course it doesn't pass through other denser materials like metals. So what one can do is you can take a photograph of somebody at terrahurt's frequencies and you'll see I'm afraid you will see through their clothes and you will reveal any hidden objects beneath.