| All-Solid-State with high power puts forward the higher requirement for the mechanical property and the laser induced damage threshold (LIDT) of the coatings in addition to the optical performance.In order to obtain high LIDT antireflective (AR) coatings on the nonlinear optical crystal LiB3O5(LBO), this dissertation focuses its main interests on the following four aspects: Firstly,frequency doubling and tripling AR coatings were designed on the LBO crystal using vector addition method. The acceptable deviation between layer thickness, refractive index and residual reflectance was discussed,which can lead us to fabricate low residual reflectance and highly repeatable AR coatings on the LBO crystal. Then, according to the design results, HfO2 with stable physical and chemical properties, high melting point and high LIDT was chose as high refractive index material. Its performance including refractive index, surface defects, crystalline structure and LIDT was studied under different ion assisted deposition (IAD) parameters. Thirdly, influence of defects and contaminants lying on substrate and coating surface, cleaning of the substrate and deposition technologies on LIDT of AR coatings on the LBO crystal was investigated. Finally, frequency doubling AR coatings—946nm,473nm and 1064nm,532nm were deposited on the LBO crystal with IAD by optimizing process condition. The measurement indicated the coatings had high LIDT, low residual reflection, good adhesion and high environmental stability. According to the damage properties of AR coating on the LBO crystal, the LIDT of the AR coatings were significantly increased by adding barrier layer.Based on above studies, we built stable fabrication process of high LIDT and low residual reflectance frequency doubling AR on the LBO crystal, which satisfied the requirement of the residual reflectance and LIDT of the project《study on All-Solid-State red, green and blue lasers and crystal materials》.
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