ABSTRACT
What are the main criteria to classify the fluorescence imaging methods? What are the basic concepts relevant to macroscopic and microscopic imaging methods? These and similar questions are answered in the first part of the chapter. Following this is a detailed description of the two most important macroscopic imaging technologies, namely planar laser-induced fluorescence imaging and fluorescence tomography. The former is discussed with the aid of examples from studies of the mechanisms in flames, combustion, and catalysis, while the latter is exemplified for tumor development in biological tissues. The second half of the chapter is dedicated to superresolution microscopy, the field that revolutionized optical microscopy by breaking the Abbé diffraction limit, leading to the development of the so-called nanoscope (a development recognized by the 2014 Nobel Prize in Chemistry). The topic of superresolution fluorescence microscopy is grouped into methods using spatially patterned excitation (STED, RESOLF, and SIM/SSIM) and those exploiting single molecule imaging (STORM, PALM, and FPALM). For all of them, the underlying physics is sketched, and a range of representative examples is discussed (predominantly from biology and biomedicine). The chapter concludes by highlighting the discovery of the green fluorescent protein as a marker for gene expression, nowadays one of the most powerful tools in the imaging of bio-organisms, and how the revolutionary development of “MINIFLUX” begins to extend superresolution microscopy to well below the 10 nm mark.
