Many applications of fluorescence require the sensitive and selective detection of fluorescence near interfaces. Highly surface-confined and efficient fluorescence collection can be achieved by the detection of near-field mediated supercritical angle fluorescence. This approach allows for undercritical angle fluorescence from the far-field to be detected from deeper axial planes separately at the same time. The book covers applications of parallel near and far-field fluorescence to sub-diffraction sub-diffraction imaging and fluorescence correlation spectroscopy. The application of supercritical angle fluorescence is extended to highly sensitive and fast biosensing.