Near-Field Radiative Heat Transfer across Nanometer Vacuum Gaps provides an in-depth description of fundamentals and application of near-field radiative heat transfer. When the vacuum gap between two media is on the order of nanometers, heat transfer can exceed that between blackbodies. This book investigates near-field heat transfer between different materials and geometries highlighting interplay between optics, material thermophysical properties and electromagnetism. The book also highlights the application of near-field thermal radiation in the field of power generation, imaging, and thermal systems as an analog of electronic devices.