Each chapter in this book is written by a group of leading experts in one particular type of microprobe technique. They emphasize the ability of that technique to provide information about small structures (i.e. quantum dots, quantum lines), microscopic defects, strain, layer composition, and its usefulness as diagnostic technique for device degradation. Different types of probes are considered (electrons, photons and tips) and different microscopies (optical, electron microscopy and tunneling). It is an ideal reference for post-graduate and experienced researchers, as well as for crystal growers and optoelectronic device makers.