Strain engineering of nonlinear boron phosphate for phase matching in ultraviolet region:a first principles study
Borophosphates,particularly BPO4(BPO)”1,2” crystals,have attracted attention in laser frequency conversion devices due to short ultraviolet cut-off edge and relatively large second harmonic generation(SHG) response with magnitude almost twice that of KH2PO4.Yet the birefringence of BPO(approximately 0.005) is too small to satisfy the phase matching condition”3” in ultraviolet spectral region,restricting the efficiency of laser output.Here we systematically examine the influence of mechanical strains on the atomic structure as well as the electronic and optical properties of BPO by the first-principles calculations applied in the CASTEP package of Materials studio.Interestingly,we find that the birefringence of BPO can be enhanced by～0.06 through the external uniaxial strain along c-axis.Meanwhile,the compressive strain can effectively increase the band gap and SHG coefficients.The refractive-index dispersion is also emphasized in this work.Our results indicate that phase matching in ultraviolet region(266 nm) could be achieved under-10 ％strain(3.9 GPa).This investigation is not only helpful for better understanding the structure-property relationship of BPO under strain,but also presents the possibility of its use as a promising ultraviolet nonlinear optical crystal.
Jinyu Hu Kechen Wu
State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,P.R.China
国内会议
大连
英文
577-578
2016-09-24（万方平台首次上网日期，不代表论文的发表时间）