With ever-increasing laser power,the requirements for ultraviolet(UV)coatings increase continuously.The fundamental challenge for UV laser-resistant mirror coatings is to simultaneously exhibit a high reflectivity wit...With ever-increasing laser power,the requirements for ultraviolet(UV)coatings increase continuously.The fundamental challenge for UV laser-resistant mirror coatings is to simultaneously exhibit a high reflectivity with a large bandwidth and high laser resistance.These characteristics are traditionally achieved by the deposition of laser-resistant layers on highly reflective layers.We propose a“reflectivity and laser resistance in one”design by using tunable nanolaminate layers that serve as an effective layer with a high refractive index and a large optical bandgap.An Al_(2)O_(3)-HfO_(2) nanolaminate-based mirror coating for UV laser applications is experimentally demonstrated using ebeam deposition.The bandwidth,over which the reflectance is >99.5%,is more than twice that of a traditional mirror with a comparable overall thickness.The laser-induced damage threshold is increased by a factor of ~1.3 for 7.6 ns pulses at a wavelength of 355 nm.This tunable,nanolaminate-based new design strategy paves the way toward a new generation of UV coatings for high-power laser applications.展开更多
基金supported by the National Special Support Program for Young Top-notch TalentNational Natural Science Foundation of China(61975215 and 61505227)+1 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciencesand Shanghai Young Top-notch Talent Program.
文摘With ever-increasing laser power,the requirements for ultraviolet(UV)coatings increase continuously.The fundamental challenge for UV laser-resistant mirror coatings is to simultaneously exhibit a high reflectivity with a large bandwidth and high laser resistance.These characteristics are traditionally achieved by the deposition of laser-resistant layers on highly reflective layers.We propose a“reflectivity and laser resistance in one”design by using tunable nanolaminate layers that serve as an effective layer with a high refractive index and a large optical bandgap.An Al_(2)O_(3)-HfO_(2) nanolaminate-based mirror coating for UV laser applications is experimentally demonstrated using ebeam deposition.The bandwidth,over which the reflectance is >99.5%,is more than twice that of a traditional mirror with a comparable overall thickness.The laser-induced damage threshold is increased by a factor of ~1.3 for 7.6 ns pulses at a wavelength of 355 nm.This tunable,nanolaminate-based new design strategy paves the way toward a new generation of UV coatings for high-power laser applications.
