High-power laser applications, spanning industrial processing, medical devices, and particle acceleration, impose increasingly stringent demands on optical thin-film coatings. However, defining “high power” for optics cannot rely on a single parameter, as survivability is governed by a complex interplay of pulse duration, repetition rate, wavelength, beam geometry, electric field distribution, coating absorption, and angle of incidence. This work redefines high-power optics through the framework of Laser-Induced Damage Threshold (LIDT), emphasizing its dependence on operational regimes and underlying damage mechanisms.

Two primary damage modes are identified: catastrophic failure, driven by deterministic electronic processes in ultrafast (fs–ps) regimes, and gradual degradation such as color-center formation, which reduces effective LIDT over time. In continuous-wave and nanosecond domains, thermal effects dominate, requiring minimization of electric field intensity in high-index layers. In contrast, ultrafast regimes are governed by avalanche ionization and multiphoton absorption, where conventional LIDT scaling laws break down across pulse duration transitions.

Ion Beam Sputtering (IBS) emerges as a critical enabling technology, producing dense, low-defect, near-zero absorption coatings with superior thermal stability. These properties ensure robust performance across both ultrafast and high-average-power regimes. Consequently, high-power optics must be defined relative to application-specific conditions, with IBS coatings providing a reliable foundation for next-generation laser systems.