标题：Nonlinear optical characteristics of an ADP crystal grown in a defined direction
作者：Lian, Yafei; Wen, Jibin; Wang, Fang; Sui, Tingting; Huang, Jin; Sun, Xun; Jiang, Xiaodong
作者机构：[Lian, Yafei; Sui, Tingting; Sun, Xun] Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Peoples R China.; [Lian, Yafei; Wen, Jibin; Wang, Fan 更多
通讯作者：Sun, X;Sun, X
通讯作者地址：[Sun, X]Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Peoples R China;[Sun, X]Shandong Univ, Key Lab Funct Crystal Mat & Device, Minist Educ 更多
来源：OPTICAL MATERIALS EXPRESS
摘要：Samples in the crystal directions of Z, X(ab) and the non-critical phase matching angle (theta = 90 degrees, phi = 45 degrees) were gained from high-quality ammonium dihydrogen phosphate (NH4H2PO4, ADP) crystals grown in the Z direction and in defined crystallographic direction (theta = 90 degrees, phi = 45 degrees) via the rapid growth method. Z-scan measurements with pico-second pulse laser irradiation at lambda = 355nm were implemented to systematically investigate their nonlinear characters, such as the nonlinear absorption coefficient beta, nonlinear refractive index n(2) and the third order nonlinear susceptibility chi((3).) The results displayed the nonlinear absorption and nonlinear refraction, and the ADP crystals exhibit the reverse saturable absorption and self-focusing effect (n(2)>0). The nonlinear absorption and refraction were anisotropic in the crystal directions of Z, X, and the non-critical phase matching angle (theta = 90 degrees, phi = 45 degrees) sorted as:  < X < Z. The remarkable NLA behaviors at 355 nm are identified to the co-existence of 2PA and 3PA, while 2PA is dominant and the occurrence probability of 3PA is rather low. The anisotropy of the NLA of ADP crystals is closely bound up with the damage anisotropy in our experiments. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.