CRC Press eBooks
Quantum Imaging
Yanhua H. Shih
Abstract
Although questions regarding fundamental issues of quantum theory still exist, quantum entanglement has started to play important roles in practical engineering applications. Quantum imaging is one of these exciting areas. Quantum imaging has so far demonstrated three peculiar features: enhancing the spatial resolution of imaging beyond the diffraction limit; reproducing ghost images in a “nonlocal” manner; and dispersion-cancelation or turbulence-free imaging. The enhanced spatial resolution apparently “violates” the uncertainty principle. The ghost imaging is considered as a “nonlocal” phenomenon due to a point-to-point correlation of two interaction-free photons at distance. All the peculiar features are the results of two-photon interference, which involves the superposition of two-photon amplitudes, a nonclassical entity corresponding to different yet indistinguishable alternative ways of creating a joint-detection event. The effect of turbulence on a classic image can be easily seen from the blurring of the images.