09 Oct '14 21:38>3 edits
Is it possible to make a device that can detect single photons of radio waves with wavelengths of many meters even if they enter the device at a rate of no more than, say, one per second and, if so, how might it basically work?
I tried googling this but got nowhere.
I understand the main reason why radio detectors are not designed to detect single photons of radio waves is because each photon has such a small amount of energy that their energy is indistinguishable from typical thermal energy in the same detector thus there would be the problem of the detector seeing itself! So could, in theory at least, you make a camera (as opposed to a radio dish ) that can detect individual radio photons providing you made it cold enough; say, 0.1K?
I guess it would have to be a huge camera with an aperture many kilometers in diameter else, because of the diffraction limit, the image would be too blurred to be of much use. But perhaps it could have a radio-frequency lens made of a metamaterial to get around that?
I tried googling this but got nowhere.
I understand the main reason why radio detectors are not designed to detect single photons of radio waves is because each photon has such a small amount of energy that their energy is indistinguishable from typical thermal energy in the same detector thus there would be the problem of the detector seeing itself! So could, in theory at least, you make a camera (as opposed to a radio dish ) that can detect individual radio photons providing you made it cold enough; say, 0.1K?
I guess it would have to be a huge camera with an aperture many kilometers in diameter else, because of the diffraction limit, the image would be too blurred to be of much use. But perhaps it could have a radio-frequency lens made of a metamaterial to get around that?