摘要
Non-π-conjugated groups have recently emerged as excellent fundamental building blocks(FBUs)for UV nonlinear optical(NLO)crystals,due to their ability to achieve wide transparency.However,their generally high crystallographic symmetry often results in limited optical anisotropy,making few resultant crystals phase-matchable in the UV wavelength range.In this work,we introduce the polar[NH(CH_(2)SO_(3))_(2)]^(2−)dimer as a novel non-π-conjugated FBU,and synthesize the first NLO iminodimethanesulfonate crystal,namely Cs_(2)NH(CH_(2)SO_(3))_(2)·H_(2)O.Experimental results demonstrate that this crystal exhibits second-harmonic generation(SHG)responses with 0.8 times of KDP,moderate birefringence of 0.044@550 nm,and broad UV transparency(<200 nm),enabling phase-matchable SHG at the key UV wavelength of 266 nm.First-principles calculations confirm that polar[NH(CH_(2)SO_(3))_(2)]^(2−)dimers contribute to the optical properties of Cs_(2)NH(CH_(2)SO_(3))_(2)·H_(2)O.This work highlights an excellent UV NLO-active FBU for exploring high-performance UV NLO crystals.
基金
the financial support from the National Natural Science Foundation of China(22193042 and 22405273)
the Natural Science Foundation of Fujian Province(2022J02012)
the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLHO24)
the Postdoctoral Fellowship Program of CPSF under Grant Number GZB20240747
the China Postdoctoral Science Foundation(2023M743498)
Young Elite Scientist Sponsorship Program by CAST(YESS20230117).
