This book provides a series of methods for flexibly and actively manipulating thermal emission and photoluminance by advanced nanostructures—metamaterials. Nanostructures in subwavelength scales can be designed to precisely modulate light-matter interactions and thereby tailoring both thermal radiations and photon emissions. This book explores approaches for designing different kinds of nanostructures, including multilayers, gratings, nanoridges, and waveguides, to improve the flexibility and functionality of micro/nanodevices. With the help of these subwavelength nanostructures, thermal...