Promising Nonlinear Optical Material Research Articles

Theoretical investigation on the second order nonlinear optical properties of heptagon bridged bi-porphyrin derivatives

Porphyrins and their derivatives have drawn extensive attention as promising nonlinear optical (NLO) materials especially for biological applications owing to its large aromatic conjugation and special biological activity and compatibility. However, it is still critical to strategically design porphyrin derivatives materials with high performance in second order NLO applications and disclose the structure property correlation. In the present work, a series of dual-metallic-porphyrin derivatives are designed by incorporating a heptagon between two porphyrins with further addition of heteroatoms and metals. The doping of B and N along the dipole direction induces large static first hyperpolarizability, and strong charge transfer occurs with further introduction of Mg, thus ultimately achieving excellent second order NLO properties including strong sum frequency generation and difference frequency generations under external fields. The doping of heteroatoms and metals synergistically tunes the electronic structure of porphyrin-based derivatives and brings about high performance in biological nonlinear optics.

From CaBaM2F12 to K2BaM2F12 (M = Zr, Hf): Heterovalent Cation-Substitution-Induced Symmetry Break and Nonlinear-Optical Activity.

Designing short-wavelength nonlinear-optical (NLO) crystals is of vital importance for laser applications. Here, the combination of alkaline-earth metals, d0 transition metals, and F atom has generated two new and isostructural fluorides, CaBaZr2F12 (CBZF) and CaBaHf2F12 (CBHF), which adopt centrosymmetric space group I4/mmm. Taking CBZF and CBHF as the parents, two new fluorides, K2BaZr2F12 (KBZF) and K2BaHf2F12 (KBHF), with an Imm2 polar structure were obtained via a heterovalent cation substitution strategy. All four compounds feature ZrF8-dodecahedra-built {[Zr2F12]4-}∞ chains and show short ultraviolet cutoff edges (<200 nm). KBZF and KBHF show phase-matchable behavior with moderate second-harmonic-generation responses [0.6 and 0.35 × KH2PO4 (KDP)] under 1064 nm laser radiation. This work enriches fluorides as promising short-wavelength NLO materials.

Structure‐Prediction‐Oriented Synthesis of Thiophosphates as Promising Infrared Nonlinear Optical Materials

Oriented synthesis of functional materials is a focus of attention in material science. As one of the most important function materials, infrared nonlinear optical materials with large second harmonic generation effects and broad optical bandgap are in urgent need. In this work, directed by the theoretical structure prediction, the first series of non‐centrosymmetric (NCS) alkali‐alkaline earth metal [PS4]‐based thiophosphates LiCaPS4 (Ama2), NaCaPS4 (P21), KCaPS4 (Pna21), RbCaPS4 (Pna21), CsCaPS4 (Pna21) were successfully synthesized. Comprehensive characterizations reveal that ACaPS4 could be regarded as promising IR NLO materials, exhibiting wide bandgap (3.77‐3.86 eV), moderate birefringence (0.027‐0.064 at 1064 nm), high laser‐induced damage threshold (LIDT, ~10 × AGS), and suitable phase‐matching second harmonic generation responses (0.4‐0.6 × AGS). Structure‐properties analyses illustrate that the Ca‐S bonds show non‐ignorable covalent feature, and [PS4] together with [CaSn] units play dominant roles to determine the bandgap and SHG response. This work indicates that Li‐, Na‐ and K‐ analogs may be promising infrared nonlinear optical material candidates, and this is the first successful case of “prediction to synthesis” involving infrared (IR) nonlinear optical (NLO) crystals in the thiophosphate system and may provide a new avenue to the design and oriented synthesis of high‐performance function materials in the future.

Structure-Prediction-Oriented Synthesis of Thiophosphates as Promising Infrared Nonlinear Optical Materials.

Oriented synthesis of functional materials is a focus of attention in material science. As one of the most important function materials, infrared nonlinear optical materials with large second harmonic generation effects and broad optical bandgap are in urgent need. In this work, directed by the theoretical structure prediction, the first series of non-centrosymmetric (NCS) alkali-alkaline earth metal [PS4]-based thiophosphates LiCaPS4 (Ama2), NaCaPS4 (P21), KCaPS4 (Pna21), RbCaPS4 (Pna21), CsCaPS4 (Pna21) were successfully synthesized. Comprehensive characterizations reveal that ACaPS4 could be regarded as promising IR NLO materials, exhibiting wide bandgap (3.77-3.86 eV), moderate birefringence (0.027-0.064 at 1064 nm), high laser-induced damage threshold (LIDT, ~10 × AGS), and suitable phase-matching second harmonic generation responses (0.4-0.6 × AGS). Structure-properties analyses illustrate that the Ca-S bonds show non-ignorable covalent feature, and [PS4] together with [CaSn] units play dominant roles to determine the bandgap and SHG response. This work indicates that Li-, Na- and K- analogs may be promising infrared nonlinear optical material candidates, and this is the first successful case of "prediction to synthesis" involving infrared (IR) nonlinear optical (NLO) crystals in the thiophosphate system and may provide a new avenue to the design and oriented synthesis of high-performance function materials in the future.

Sr2HgGe2OS6: A Hg-Based Oxychalcogenide Infrared Nonlinear Optical Material Exhibiting Favorable Balance between a Large Band Gap and Strong Second Harmonic Generation Response.

Currently, oxychalcogenides with mixed-anion groups that integrate the property advantages of oxides (wide optical band gap) and chalcogenides [strong second harmonic generation (SHG) response] through chemical substitution engineering have attracted widespread interest and are considered to be important candidates for infrared (IR) nonlinear optical (NLO) materials. Herein, the first Hg-based oxychalcogenide Sr2HgGe2OS6 with mixed anion [GeOS3] units has been successfully synthesized through a spontaneous crystallization method, which exhibits a favorable balance between the strong SHG response (0.7 × AgGaS2) and large optical band gap (2.9 eV). In addition, Sr2HgGe2OS6 shows high laser-induced damage threshold (LIDT, 2.1 × AgGaS2) as well as phase-matching (PM) performance. Theoretical calculations indicate that the Sr2HgGe2OS6 encompasses large birefringence of 0.128@2090 nm (3.3 × AgGaS2) and its SHG density mainly comes from [HgS4] tetrahedra and [GeOS3] units. This work not only demonstrates that Sr2HgGe2OS6 is a promising IR NLO material but also provides new ideas for the exploration of Hg-based oxychalcogenide IR NLO materials.

LaMg6Ga6S16: a chemical stable divalent lanthanide chalcogenide

Divalent lanthanide inorganic compounds can exhibit unique electronic configurations and physicochemical properties, yet their synthesis remains a great challenge because of the weak chemical stability. To the best of our knowledge, although several lanthanide monoxides epitaxial thin films have been reported, there is no chemically stable crystalline divalent lanthanide chalcogenide synthesized up to now. Herein, by using octahedra coupling tetrahedra single/double chains to construct an octahedral crystal field, we synthesized the stable crystalline La(II)-chalcogenide, LaMg6Ga6S16. The nature of the divalent La2+ cations can be identified by X-ray photoelectron spectroscopy, X-ray absorption near-edge structure and electron paramagnetic resonance, while the stability is confirmed by the differential thermal scanning, in-situ variable-temperature powder X-ray diffraction and a series of solid-state reactions. Owing to the particular electronic characteristics of La2+(5d1), LaMg6Ga6S16 displays an ultrabroad-band green emission at 500 nm, which is the inaugural instance of La(II)-based compounds demonstrating luminescent properties. Furthermore, as LaMg6Ga6S16 crystallizes in the non-centrosymmetric space group, P−6, it is the second-harmonic generation (SHG) active, possessing a comparable SHG response with classical AgGaS2. In consideration of its wider band gap (Eg = 3.0 eV) and higher laser-induced damage threshold (5×AgGaS2), LaMg6Ga6S16 is also a promising nonlinear optical material.

Stable Q-switched and femtosecond mode-locked erbium-doped fiber laser based on a CuSe nanosheets saturable absorber.

Stable Q-switched and femtosecond mode-locked erbium-doped fiber laser (EDFL) have been achieved using CuSe nanosheets as novel saturable absorber (SA), where the CuSe nanosheets were prepared by a hydrothermal method. The nonlinear optical properties of CuSe nanosheets were measured using an Z-scan setup, revealing nonlinear absorption coefficients of -3.67 ± 0.22 cm GW-1 at 1560 nm. The prepared CuSe nanosheets were mixed with polyvinyl alcohol (PVA) to obtain a CuSe-PVA SA with a modulation depth of 3.8 ± 0.13%, and it was utilized to realize a Q-switched EDFL, obtaining the narrowest pulse duration of 1.29 µs and the maximum output power of 5.96 mW, which corresponds to a pulse energy of up to 103.7 nJ. In addition, CuSe nanosheets were deposited on a D-shaped fiber (DSF) to fabricate a CuSe-DSF SA with a modulation depth of 5.6 ± 0.17%, and it was utilized to realize a mode-locked EDFL. The mode-locked EDFL demonstrated a low threshold of only 42 mW, a pulse duration of 740 fs, and a maximum output power of 9.7 mW. Meanwhile, it exhibited a high signal-to-noise ratio of 72 dB. To the best of our knowledge, this is the first time of CuSe nanosheets as SA in EDFL. The results demonstrate that CuSe nanosheets are a highly promising nonlinear optical material with great potential for applications in ultrafast photonics.

Influence of Polar Solvents on Third-Order Nonlinear Optical Features of Methyl Red Dye.

This study emphasis the solvent effect on third-order nonlinear optical (NLO) features of methyl red (MR) dye dissolved in polar solvents including ethanol, methanol, acetone, 1-propanol, DMF and DMSO using low power diode laser. Z-scan technique operating at 405nm wavelength, is used to estimate the third-order NLO features of MR dye in various solvents. The dye discloses self-defocusing nonlinear index of refraction (n2), which is determined to be the order of 10-7 cm2/W. The nonlinear coefficient of absorption (β) of MR dye displays both negative and positive value owing to saturable absorption (SA) and reverse saturable absorption (RSA), respectively. The real and imaginary components of the third-order NLO susceptibility of MR dye in polar solvents are measured to be the order of 10-6 esu and 10-7 esu, respectively. The dye exhibits a large NLO susceptibility in DMSO, which is estimated to be 1.21 × 10-6 esu. The effect of solvent spectral features on MR dye is determined by applying a multi-parameter scale called Kamlet-Abboud-Taft. The experiment results indicate that MR dye is a promising NLO material that may find applications in photonics and optoelectronics.

Third Harmonic Generation in Thin NbOI2 and TaOI2.

The niobium oxide dihalides have recently been identified as a new class of van der Waals materials exhibiting exceptionally large second-order nonlinear optical responses and robust in-plane ferroelectricity. In contrast to second-order nonlinear processes, third-order optical nonlinearities can arise irrespective of whether a crystal lattice is centrosymmetric. Here, we report third harmonic generation (THG) in two-dimensional (2D) transition metal oxide iodides, namely NbOI2 and TaOI2. We observe a comparable THG intensity from both materials. By benchmarking against THG from monolayer WS2, we deduce that the third-order susceptibility is approximately on the same order. THG resonances are revealed at different excitation wavelengths, likely due to enhancement by excitonic states and band edge resonances. The THG intensity increases for material thicknesses up to 30 nm, owing to weak interlayer coupling. After this threshold, it shows saturation or a decrease, due to optical interference effects. Our results establish niobium and tantalum oxide iodides as promising 2D materials for third-order nonlinear optics, with intrinsic in-plane ferroelectricity and thickness-tunable nonlinear efficiency.

Gap-Free Tuning of Second and Third Harmonic Generation in Mechanochemically Synthesized Nanocrystalline LiNb1−xTaxO3 (0 ≤ x ≤ 1) Studied with Nonlinear Diffuse Femtosecond-Pulse Reflectometry

The tuning of second (SHG) and third (THG) harmonic emission is studied in the model system LiNb 1−xTa xO 3 (0≤x≤1, LNT) between the established edge compositions lithium niobate (LiNbO 3, x=0, LN) and lithium tantalate (LiTaO 3, x=1, LT). Thus, the existence of optical nonlinearities of the second and third order is demonstrated in the ferroelectric solid solution system, and the question about the suitability of LNT in the field of nonlinear and quantum optics, in particular as a promising nonlinear optical material for frequency conversion with tunable composition, is addressed. For this purpose, harmonic generation is studied in nanosized crystallites of mechanochemically synthesized LNT using nonlinear diffuse reflectometry with wavelength-tunable fundamental femtosecond laser pulses from 1200 nm to 2000 nm. As a result, a gap-free harmonic emission is validated that accords with the theoretically expected energy relations, dependencies on intensity and wavelength, as well as spectral bandwidths for harmonic generation. The SHG/THG harmonic ratio ≫1 is characteristic of the ferroelectric bulk nature of the LNT nanocrystallites. We can conclude that LNT is particularly attractive for applications in nonlinear optics that benefit from the possibility of the composition-dependent control of mechanical, electrical, and/or optical properties.

RbPbPS4: a promising IR nonlinear optical material achieved by lone-pair-cation-substitution-induced structure transformation

A novel excellent IR-NLO material RbPbPS4 with superior comprehensive performances is provided, representing the first quaternary Pb-based chalcogenide breaks through the incompatibility between a large Eg and a strong deff.

K(NH4)Zn2(PO4)2: a Beryllium-Free Sr2Be2B2O7 Derivative with Enhanced Interlayer Connectivity.

A novel zinc phosphate derivative of Sr2Be2B2O7 (SBBO), K(NH4)Zn2(PO4)2 (KNZP), featuring [Zn2P2O8]∞2- double layers akin to the [Be2B2O7]∞4- layers in SBBO, was successfully synthesized via a moderate hydrothermal method. Through the substitution of BeO4 and BO3 with ZnO4 and PO4, the issue of toxicity has been effectively resolved, while the enhanced interlayer interactions facilitated by covalent and hydrogen bonding in KNZP overcome the inherent structural instability. Notably, KNZP exhibits a wide transparent window and a moderate second-harmonic generation (SHG) intensity, reaching 0.7 times that of KH2PO4 (KDP), rendering it type-I phase-matchable, indicating that it is a promising UV nonlinear optical (NLO) material.

Structural, spectroscopic and second harmonic generation evaluation of 1,2,4-triazolinium tartrate - tartaric acid as a promising nonlinear optical material

Crystallization of 1,2,4-triazole with (2R,3R)-(+)-tartaric acid (l (+)-tartaric acid) in a 1:2 ratio yields the ionic co-crystals of 1,2,4-triazolium tartrate – tartaric acid (1:1), (C2H4N3) (C4H5O6)‧C4H6O6 – (abbreviated as TATT). TATT crystallizes in the tetragonal system with a non-centrosymmetric P41212 space group of eight molecules per unit cell. Apart from ionic interaction by the building ions and N–H‧‧‧O, the 1,2,4-triazolinium cation and the tartrate anion interact through hydrogen bonds and O–H‧‧‧O with tartaric acid to form a supramolecular complex (C2H4N3) (C4H5O6)‧C4H6O6 (TATT). Hydrogen bonds further organise these supramolecular complexes into a three-dimensional network. The interactions between the building blocks of the co-crystal were analyzed using Hirshfeld surface and 2D fingerprint plots. Normal coordinate force field calculations based on density functional theory (DFT) and structure optimizations were utilized to interpret the molecular structure and fundamental vibrational frequencies. The wave numbers' complete vibrational assignments were determined through potential energy distribution (PED). The HOMO and LUMO energy gap calculations explained the charge transfer interactions within the supramolecular unit. For the TATT co-crystal, the efficiency of the second harmonic generation (SHG) process was investigated under 800 nm irradiation using the Kurtz–Perry powder technique. The ionic co-crystal demonstrated a low SHG efficiency on the order of 10−1 compared to that of KDP.

The structural origin and boundaries of thermal transitions in stillwellite-type LnBSiO5

Stillwellite-type borosilicates, LnBSiO5 represent a family of promising non-linear optical materials. The incorporation of different rare earths into the Ln sites results in complicate patterns of phase transitions. We herein analyze the high-temperature (HT) structural transformations of LnBSiO5 (Ln = Nd, Ce, La) using a suite of in situ HT methods: single-crystal structural study, powder X-ray diffraction and Raman spectroscopy, accompanied by thermal analysis. It is shown that phase transitions between the low- and high-temperature polymorphs of LnBSiO5 originate from the order-disorder in borate chains and are greatly dependent on the nature of the rare earth in the Ln sites. We showed that the high-temperature polymorphs of LnBSiO5 (Ln = Nd, Ce, La) are always metastable at ambient conditions, regardless of lanthanide cation type.

Two‐Dimensional Conjugated Metal‐Organic Framework/Graphene π–π Stacked Heterostructures for Ultrafast Photonics

Abstract2D conjugated metal‐organic frameworks (MOFs) with high in‐plane‐π‐conjugation are attracting significant attention in various fields owing to their outstanding electrical transport property, substantial specific surface areas, and tunable structures. However, their potential in ultrafast photonics has not been extensively explored. Herein, 2D conjugated Ni3(HITP)2 metal‐organic framework (MOF) and graphene (GR) π–π stacked vertical heterostructures (NG‐VHS) are synthesized using an ultrasound‐assisted method. Based on theoretical simulations and characterization analyses, the results suggest that the fast interface charge transfer and the extension of the π‐conjugated electron cloud will significantly enhance the electrical conductivity and the nonlinear optical properties, which is attributed to the π–π stacking interactions between Ni3(HITP)2 and GR. The charge transfer rate of NG‐VHS is given by 6.9 × 1011 s−1. Noticeably, NG‐VHS can serve as an excellent saturable absorber (SA) that can achieve fundamental mode‐locking with a pulse width of 451 fs, harmonic mode‐locking with repetition frequencies up to 1.205 GHz, and tunable dual‐wavelength mode‐locking. These results indicate the potential of NG‐VHS as a promising nonlinear optical material for ultrafast optical applications and a new platform for the design of advanced optoelectronic devices based on 2D conjugated MOFs.

Ln2 F2 (OH2 )(MoO3 )2 (SeO3 )2 : Promising Multifunctional Nonlinear Optical Materials Created by Partial Fluorination Strategy under Corrosion Resistant Supercritical Reactions.

It has historically been exceedingly challenging to create physically and chemically stable lanthanide compounds with strong second harmonic generation (SHG) due to their strong preference to central symmetry. In this work, five new non-centrosymmetric lanthanide selenites, namely, Ln2 F2 (OH2 )(MoO3 )2 (SeO3 )2 (Ln = Sm, Eu, Gd, Tb and Dy), are achieved by partial fluorination of the lanthanide oxygen polyhedron. An HF corrosion resistant supercritical hydrothermal method is developed, which is a facile and universal method for HF corrosion and high-temperature high-pressure environment. The title compounds displayed a novel 3D framework composed of 1D molybdenum selenite chains bridged by Ln2 F2 O12 (OH2 ) dimers. Their powder SHG responses showed a large difference, ranging from 1.0 to 9.0 × KH2 PO4 (KDP) at 1064nm. The half-filled Gd compound exhibited very strong SHG efficiency of up to 1.2 × KTP (KTiOPO4 ) at 2050nm. Compounds Tb and Gd are the first lanthanide selenites with SHG intensity reaching KTP level, which is very rare in this system. Furthermore, these compounds can also possess excellent physicochemical stability and strong luminescence emission, indicating that they are promising multifunctional nonlinear optical materials. This work offered an effective way for design and synthesis of multifunctional and high-performant nonlinear optical materials.

Impact of π-Linkers Modifications on Tuning Nonlinear Optical Amplitudes of Pyridoquinazolinone-Based Aromatic Dyes: A Rational Entry to Novel D-π-A NLO Materials

Developing efficient nonlinear optical (NLO) materials is a cutting-edge field of study. The desirability of promising NLO materials for optoelectronic applications drove us to investigate the pyridoquinazolinone-based D-π-A architectured chromophores for predicting proficient NLO compounds. Pyridoquinazolinone-based dye (WL-O) is chosen as a reference and its nine derivatives (ASH1-ASH9) are quantum chemically modeled by inserting variously reported π-linkers into the D-π-A framework. Simulations using DFT and TD-DFT provide insight into how π-linker alteration affects the NLO properties. The potential use of investigated dyes for NLO response applications is confirmed by evaluating photophysical aspects, frontier molecular orbital (FMO), natural population analysis (NPA), molecular electrostatic potential (MEP), the density of state (DOS), transition density matrix (TDM) analysis, and static, frequency-dependent NLO response properties. FMO analysis shows that all dyes’ energy gaps are lower when compared to the reference, resulting in a strong NLO response. The highest absorption wavelength of the studied dyes was found to be in the visible spectrum, as determined by UV-Vis analysis. NPA-based findings demonstrated the movement of the electrons from D to A through π-linkers resulting in the formation of a charge separation state and active NLO sensitivity of the proposed dyes. Moreover, MEP, LOL, and ELF topological investigations are performed to appraise the charge transfer inside ASH1-ASH9 and high NLO characteristics. The robust NLO response revealed the eye-catching linear polarizability(α0 ), first-hyperpolarizability (β), particularly ASH3, with the highest α0 and β0 computed to be 520.44 a.u. and 26166.79 a.u., respectively. Additionally, frequency-dependent hyperpolarizability SHG β(−2ω,ω,ω) and EOPE β(−ω,ω,0) calculations for commonly used lasers were performed at 1907.21, 532, and 1064 nm. ASH3 with terthiophene linker exhibits a striking EOPE β(−ω,ω,0) and SHG β(−2ω,ω,ω) response of 2.94 × 104 a.u. and 3.80 × 104 a.u. respectively at 1907.21 nm. This theoretical framework confirmed that the investigated dyes have fine NLO potential and are recommended for future NLO applications.

Effective third harmonic generation of 355 nm ultraviolet laser based on the borate-phosphate Ba3(ZnB5O10)PO4 crystal

An effective third harmonic generation (THG) 355 nm laser in a novel Ba3(ZnB5O10)PO4 (BZBP) crystal was demonstrated. Based on the phase matching (PM) calculation, the BZBP crystal has the type-I PM angle of θ = 90°, ϕ = 73.2° for generating the THG 355 nm laser, with a large acceptance angle of 66.3 mrad·mm and a small walk-off angle of 6.06 mrad. Using a nanosecond 1064 nm laser as the pump source, the THG 355 nm laser could achieve the maximum conversion efficiency of 28.4%, and the highest output power of 0.56 W. In addition, BZBP crystal also has a small weak absorption coefficient of 20-40 ppm/cm and a laser damage threshold of 1.04 GW/cm2. The achieved results indicate that the BZBP crystal is a promising UV nonlinear optical material due to its short absorption edge (180 nm), small walk-off effect, large acceptance angle, and non-hygroscopicity.

BaCu2SiS4: A New Member of the AIIBI2MIVQ4 Chalcogenide Family with a Chiral Crystal Structure

AbstractNoncentrosymmetric ternary and quaternary chalcogenides are studied as promising nonlinear optical (NLO) materials in the mid‐infrared region. Here, we report the synthesis of a new material BaCu2SiS4 in the AIIBI2MIVQ4 family (A=divalent metal; B=monovalent metal; M=tetrel, Q=chalcogen), and discuss its crystal structure, thermal stability, optical behavior, and electronic structure. BaCu2SiS4 crystallizes in the noncentrosymmetric chiral space group P3221 with lattice parameters a=6.1440(3) Å, c=15.3542(8) Å, V=501.95(6) Å3, Z=3. The structure features helical channels formed by corner‐sharing [CuS4] and [SiS4] tetrahedral units. Synthesis was carried out in a molten salt flux, as opposed to a traditional solid‐state route from elements, to minimize the formation of a competing ternary phase, Ba2SiS4. BaCu2SiS4 is a semiconductor with an experimentally‐determined direct bandgap of ~2.2 eV. The material exhibits second harmonic generation (SHG) activity, confirming the noncentrosymmetric nature of the structure. Analysis of reported AIIBI2MIVQ4 crystal structures pointed out a correlation among potential structure types and the radii of the constituent elements. Total energy calculations were carried out to explore the relative stability of several reported crystal structures in this family of compounds.

Mixed Anionic Tetrahedra Guided Design of New Infrared Nonlinear Optical Material Cs3Ga8S13Cl with High Laser‐Induced Damage Threshold

AbstractThe development of anti‐laser damage infrared (IR) nonlinear optical (NLO) materials is an urgent need but challenging due to the contradiction between wide bandgap and large NLO coefficient. Herein, by introducing a halogen into the NLO‐active tetrahedral unit, two halogenated metal chalcogenides Cs3Ga8S13Cl and Cs9Ga8Se12Cl9 with unprecedented [GaQ3Cl] (Q = S/Se) tetrahedral units are rationally designed and fabricated in experiments by the flux method, enriching the chemical and structural diversity of chalcogenides. Cs3Ga8S13Cl shows a wide bandgap of ≈3.76 eV, resulting in a high laser‐induced damage threshold of ≈8 × AgGaS2 (AGS) and a moderate NLO response (≈0.6 × AGS) with phase‐matching behavior. The results imply that Cs3Ga8S13Cl is a promising IR NLO material for the high powder laser application and demonstrate the feasibility of the halogenated tetrahedron strategy in regulating the optical properties of chalcogenides.