High-energy lasers is a specialized field within optics and photonics focused on the study, development, and application of laser systems designed to produce beams with exceptionally high pulse energy (measured in joules) or average power (measured in watts). This research domain investigates the fundamental physics and engineering challenges associated with generating, propagating, and controlling such intense electromagnetic radiation, as well as its unique interactions with various forms of matter, including plasmas and dense materials. Key characteristics include achieving peak or average power levels significantly exceeding those of conventional lasers, enabling applications in areas such as inertial confinement fusion, particle acceleration, advanced manufacturing, and directed energy systems, thereby pushing the boundaries of scientific and technological capability.