Open AccessCrystal growth and optical characteristics of beryllium-free polyphosphate, KLa(PO3)4, a possible deep-ultraviolet nonlinear optical crystal
Author(s) -
Pai Shan,
Tongqing Sun,
Hong Chen,
Hongde Liu,
Shaolin Chen,
Xuanwen Liu,
Yongfa Kong,
Jingjun Xu
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep25201
Subject(s) - polyphosphate , beryllium , crystal (programming language) , ultraviolet , crystal growth , nonlinear optical , materials science , optoelectronics , chemistry , crystallography , nonlinear system , physics , computer science , biochemistry , organic chemistry , phosphate , programming language , quantum mechanics
Deep-ultraviolet nonlinear optical crystals are of great importance as key materials in generating coherent light with wavelength below 200 nm through cascaded frequency conversion of solid-state lasers. However, the solely usable crystal in practice, KBe 2 BO 3 F 2 (KBBF), is still commercially unavailable because of the high toxicity of beryllium-containing and the extreme difficulty of crystal growth. Here, we report the crystal growth and characteristics of an beryllium-free polyphosphate, KLa(PO 3 ) 4 . Centimeter-sized single crystals have been easily obtained by the flux method and slow-cooling technique. The second-harmonic generation efficiency of KLa(PO 3 ) 4 powder is 0.7 times that of KH 2 PO 4 ; moreover, the KLa(PO 3 ) 4 crystal is phase-matchable. Remarkably, the KLa(PO 3 ) 4 crystal exhibits an absorption edge of 162 nm, which is the shortest among phase-matchable phosphates so far. These attributes make KLa(PO 3 ) 4 a possible deep-ultraviolet nonlinear optical crystal. An analysis of the dipole moments of the polyhedra and theoretical calculations by density functional theory were made to elucidate the structure-properties relationships of KLa(PO 3 ) 4 .