Optomechanical analysis and performance optimization of large-aperture KDP frequency converter. (January 2019)

• Record Type: Journal Article
• Authors: Zhang, Zheng; Wang, Hui; Quan, Xusong; Pei, Guoqing; Tian, Menjiya; Liu, Tianye; Long, Kai; Li, Pengda; Rong, Yiming
• Is Part Of: Optics & laser technology. Volume 109(2019)
• Page Start: 633
• Page End: 642
• Publication Date: 2019-01
• Subjects: Optics -- Surface optimization -- Frequency conversion -- Optomechanics; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2018.08.053
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Surface textures greatly influence the frequency conversion of large-aperture KDP crystal. Optical performances of KDP converter are highly correlated with the external forces. Integrated optomechanical method is developed to evaluate mechanical influences on optical performances. The edge-adaptive clamping apparatus is significant in improving the crystal's working performance. Abstract: Surface characteristics of large-aperture potassium dihydrogen phosphate (KDP) frequency converter have direct and significant impacts on the performance of high-power solid-state laser in Inertial Confinement Fusion (ICF) facility. In this study, we analyze the close relationships between the phase gradient and the optical performances including type-I phase matching capacity and focusability of KDP frequency converter theoretically. Moreover, the influences of external forces are studied with field interferometry and finite element method (FEM). An edge-adaptive clamping apparatus with two-stage preload controllers (TSPCs) is proposed to mitigate the gravitational effect. With the proposed integrated optomechanical method and principle verification experiment, new clamping method is proved to be effective to perform offline precision calibration, improve frequency conversion efficiency and has potential for use in online surface control of this large-aperture transmission optics. The coupled effects of preload and gravity on optical performance are analyzed for identifying the characteristics of new clamping method, and the optimal preloads at typical installation attitudes are determined.