Ln3GaS6 (Ln = Dy, Y): new infrared nonlinear optical materials with high laser induced damage thresholds

Abstract

Two new ternary rare earth chalcogenides, Dy3GaS6 (1) and Y3GaS6 (2), are reported here. They both crystallize in the orthorhombic space group Cmc21 (no. 36). Both are synthesized in pure phase and show phase-matchable second harmonic generation (SHG) of about 0.2 and 0.5 times, respectively for 1 and 2, as strong as that of KTiOPO4 (KTP) based on the powder SHG measurement at the wavelength of 1910 nm. They possess high powder laser induced damage thresholds (LIDTs), respectively, about 14 and 18 times that of AgGaS2 (AGS) based on the powder LIDT measurements under 1064 nm laser irradiation. They both exhibit wide transparency in the IR region (2.5–25 μm). It is believed that the title compounds are new candidates for nonlinear optical (NLO) materials in the IR region. To gain further insights into the NLO and LIDT properties of 1 and 2, the calculations of second-order NLO susceptibility and lattice energy density (LED) were also performed to explain their SHG efficiencies and high LIDTs.

EuHgGeSe4 and EuHgSnS4: Two Quaternary Eu-Based Infrared Nonlinear Optical Materials with Strong Second-Harmonic-Generation Responses

“…We have also investigated the SHG effects, band gap values, and phase matchability of some IR-NLO lanthanides, as displayed in Table S6. The Eu-based members in the M II M′ II M IV Q 4 family, especially EuCdGeQ 4 , possess distinct advantages while other lanthanide-containing IR NLO materials show weak or modest SHG responses (Y 3 GaS 6 , 0.5× that of KTP; La 2 CuSbS 5 , 0.5× that of AGS; YBa 2 InSe 5 , 1× that of AGS) − or are non-phase-matchable (Sm 4 GaSbS 9 , 3.8× that of AGS; La 6 Ga 2 GeS 14 , 4.8× that of AGS; Eu 2 Ga 2 GeS 7 , 1.6× that of AGS). − …”

Computational design of inorganic nonlinear optical crystals based on a genetic algorithm

“…The investigation of new second-order nonlinear optical (NLO) materials has attracted considerable attention due to the important applications of these materials in optoelectronic technologies, such as in optical parametric oscillators (OPO), difference frequency generation (DFG), laser frequency conversion, and signal communication. 1,2 Significant efforts have been made to develop new NLO crystals, and in the past few years many new inorganic NLO crystals have been synthesized, including some metal chalcogenides (e.g., APSe 6 (A = K, Rb), 3,4 AAsQ 2 (A = Li, Na; Q = S, Se), 5,6 AZrPQ 6 7,8 and A 4 GeP 4 Q 12 (A = K, Rb, Cs; Q = S, Se), 9 Ln 4 GaSbS 9 (Ln = Pr, Nd, Sm, Gd-Ho), 10 and Ln 3 GaS 6 (Ln = Dy, Y) 11 ), halides (e.g., Rb 2 CdBr 2 I 2 , 12 Cs 2 HgI 2 Cl 2 , 13 Hg 2 Br 3 I, 14 and HgBrCl 15 ), and borates (e.g., NaSr 3 Be 3 B 3 O 9 F 4 , 16 Na 2 Be 4 B 4 O 11 and LiNa 5 Be 12 B 12 O 33 , 17 Ba 4 B 11 O 20 F, 18 Cd 5 B 3 O 9 F, 19 and K 3 B 6 O 10 Br 20 ). A NLO crystal with excellent performance requires several conditions to be satisfied, including a high coefficient of second-order harmonic generation (SHG), a wide transparent region, good phase matchability, a moderate laser damage threshold, and the availability of the corresponding large-size crystal.…”

Na6MQ4 (M=Zn, Cd; Q=S, Se): Promising New Ternary Infrared Nonlinear Optical Materials

“…Commercial AgGaS 2 powders with the same size were used as references. Along with the increase of the laser energy, the change in color of the powder sample was constantly observed by optical microscopy to evaluate the LDT [66, 67] . To adjust different laser beams, an optical concave lens was added to the laser path.…”