Enhancement Of Nonlinear Optical Properties Research Articles

The enhancement of nonlinear optical properties of azulene-based nanographene by N atoms: a finishing touch

Functionalization of graphene-based nanomaterials by proper N-doping provides a new strategy for electronic structure modulation to enhance the second- or third-order nonlinear optical properties of materials.

Cascade amplification of optical absorption on III–V semiconductors via plasmon-coupled graphene

Plasmons in graphene (Gr) show many fascinating characteristics, such as dynamic tunability, strong field confinement of light-matter interaction, and highly responsive, which has been widely exploited for a number of applications, including photodetectors, optical modulators, and sensors. In this paper, graphene plasmons (GPs) were motivated by implanting Au nanoparticles (Au NPs) into Ta2O5 thin layers adjacent to the Gr film, and the strong localized surface plasmon resonance (LSPR) effect has been proposed and demonstrated by placing the GPs structure on a III–V semiconductor quantum well saturable absorber (SA). It has been substantiated that the heightened interaction between light and Gr via LSPR predominantly occurs through the mechanisms of resonant energy transfer and local electromagnetic field enhancement, rather than direct electron transfer. Significant improvement on the nonlinear characteristics of the GPs modulated III–V semiconductor SA has been observed with a 17.1% large modulation depth and obviously improved working stability. A 1550 nm passive mode-locked laser has been successfully constructed with a pulse width down to 523 fs by integrating the SA into the laser cavity. This work lays the foundation for the development of high-performance mode-locked lasers and also demonstrates the substantial enhancement of nonlinear optical properties of various materials not limited to III–V semiconductors provided by this GPs' modulated structure; hence, these findings offer extensive prospects for applications in various photonics and optoelectronic devices.

Bi/Ti3C2Tx composites: Synthesis and enhanced nonlinear optical and electrochemical properties

The Bi/Ti3C2Tx composites were synthesized by a hydrothermal method. Then the Bi/Ti3C2Tx powder was dispersed into methyl methacrylate (MMA) to fabricate the (Bi/Ti3C2Tx)2–6/polymethyl methacrylate (PMMA) organic glasses. The crystalline structure and phase of the Bi/Ti3C2Tx were measured by the X-ray diffraction. The photoluminescence (PL) spectra and the electrochemical impedance spectra (EIS) of the Bi/Ti3C2Tx were measured to prove the enhanced optical and electrical properties. The nonlinear optical (NLO) properties of the (Bi/Ti3C2Tx)2–6/PMMA organic glasses were investigated by the Z-scan technique. The (Bi/Ti3C2Tx)2–6/PMMA organic glasses exhibit the reverse saturable absorption (RSA) and self-defocusing effects. Compared to the (Bi)2/PMMA and (Ti3C2Tx)2/PMMA organic glasses, the (Bi/Ti3C2Tx)2–6/PMMA organic glasses exhibit the enhanced NLO properties. Among three different amount Bi/Ti3C2Tx/PMMA organic glasses, (Bi/Ti3C2Tx)4/PMMA organic glass exhibits the strongest RSA and self-defocusing effects with βeff = (6.34 ± 1.90)× 102 cm·GW−1 and γ = (–3.52 ± 0.07)× 10−4 cm2·GW−1. The enhanced RSA and self-defocusing effect of the (Bi/Ti3C2Tx)2–6/PMMA organic glasses make them exhibit the excellent optical limiting (OL) performance. In addition, the Bi/Ti3C2Tx composites show excellent electrochemical performance as an electrode material for energy storage systems. The resultant Bi/Ti3C2Tx electrode yields a high specific capacity of 68.5 mAh·g−1 at a current density of 1 A·g−1, which is approximately 4.2 and 6.1 times than those of the Bi and Ti3C2Tx electrodes, respectively. The experimental results exhibit the Bi/Ti3C2Tx is highly promising for energy storage and OL devices.

Polar Phosphorus Chalcogenide Cage Molecules: Enhancement of Nonlinear Optical Properties in Adducts.

The inorganic adduct is an emergent class of infrared nonlinear optical (NLO) materials. However, although the reported NLO adducts have sufficient birefringences and significant laser-induced damage thresholds (LIDTs), they commonly suffer from weak second harmonic generation (SHG) responses. In this work, a series of polar phosphorus chalcogenide cage molecules with strong hyperpolarizabilities were theoretically screened out to enhance the SHG responses of adducts. Accordingly, (CuI)3(P4S4), (CuI)3(P4Se4), (CuBr)7(P4S3)3 and (CuBr)7(P4Se3)3 with target polar cage molecules were successfully synthesized. As expected, they exhibit enhanced SHG responses while keeping moderate birefringences and high LIDTs. Notably, (CuBr)7(P4Se3)3 possesses the largest SHG response (3.5×AGS@2.05 μm) among the known inorganic NLO adducts. Our study confirms that introducing NLO-active cage molecules into adducts is an efficient strategy for high-performance NLO materials.

NLO properties and electride characteristics of superalkalis doped all-cis-1,2,3,4,5,6-hexafluorocyclohexane complexes

The designing and synthesis of efficient NLO materials is the demand of the century because of their importance in the development of photo-electronic devices. Herein, we studied the geometric, electronic, and nonlinear properties of superalkalis doped all-cis-1,2,3,4,5,6-hexafluorocyclohexane, Janus type complexes. These complexes have an unprecedented involvement of respective superalkalis as source of excess electrons, which resulted in the enhancement of nonlinear optical properties and electride characteristics. The interaction energies (−13.57 to −16.54 kcal mol−1) indicated the physisorption of superalkalis on C6H6F6. NBO charge analysis is used to predict the charge transfer during the complexation. The highest NLO response (1.68 ×106 au) is observed for Na2F@C6F6H6 complex. The enhancement in second hyperpolarizability (γo) values is seen at various frequencies. Further, to obtain NLO response from an experimental point of view, hyper Rayleigh scattering (βHRS) is also investigated. These complexes, in addition to being a new entry into excess electron compounds, will pave the way for the designing and synthesis of additional NLO materials. The remarkable static first hyperpolarizability (βo) and second hyperpolarizability (γo) responses make them ideal for future NLO materials.

Structural, spectroscopic, FMOs, and non-linear optical properties exploration of three thiacaix(4)arenes derivatives

Computational exploration has been carried out on three p-tertbutylthiacalix[4]arene derivatives, namely cone (a), partial-cone (b), and 1,3-alternate (c). These three compounds are recently synthesized in high yields (80, 95, and 85%, respectively) and characterized by our group, which showed high uptake efficacy of alkali, heavy, and transition metal ions via liquid–liquid extraction. Significantly, these compounds exhibited high uptake capacity for Cu(II) (74.9 %) and Pb(II) (80.0%) upon using cone (a), and partial-cone (b), respectively. In this study, in order to optimize how the thiacalix[4]arene (as a nucleophilic) interacts with the metal ion (as an electrophile), DFT calculations were undertaken. Theoretical IR and UV–Vis spectral features of the titled compounds were computed and compared with their experimental values. Chemical reactivity was ranked based on selected electronic chemical descriptors. Moreover, the active sites of the three compounds were determined by molecular electrostatic potential (MEP) maps. Furthermore, non-linear optical (NLO) properties were investigated and compared with urea as reference material. The results of NLO characteristics showed that the subject compounds are excellent candidates as NLO materials. The enhancement of NLO properties can be qualitatively explained by means of high charge transfer pattern.

Enhancement in non-linear optical properties of carbon nitride (C2N) by doping superalkali (Li3O): A DFT study

A systematized analysis of the electronic as well as the nonlinear optical properties of carbon nitride (C2N) doped with superalkali (Li3O) has been investigated through density functional theory (DFT) methods of B3LYP, LC-BLYP, and CAM-B3LYP at 6-31G (d,p) basis set. The FMOs value by the B3LYP method of DFT has been proved more promising to the experimental value of carbon nitride. So, it is employed as a more reliable method for computations. Doped molecules (M2 and M3) have a high interaction energy (-6.68 eV) and vertical ionization energy (3.46 eV), reduced energy gap in comparison with pure C2N indicating that designed complexes are more stable than pure C2N surface. The up-turn of UV absorption, dipole moment, and first hyperpolarizability have improved the electronic properties and interaction energies between the superalkali and carbon nitride after doping. The first hyperpolarizability and dipole moment of Li3O doped with pure surface has been increased up to 321,498 au and 5.31 D respectively. All results proved that Li3O doped with carbon nitride is a potential approach to synthesize the material by doping super alkali on carbon nitride for nonlinear optical devices.

Pd and octahedra do not get along: Square planar [PdS4] units in non-centrosymmetric La6PdSi2S14

Non-linear optical (NLO) materials require a balance of high second-harmonic generation (SHG) signal and laser damage threshold (LDT), as well as phase matchable behavior. Herein, we report a new member of the (RE)6(TM)x(Tt)2Q14 family of compounds, La6PdSi2S14, which, unlike all other reported TM analogues crystallizing in hexagonal P63 space group, crystallizes in the non-centrosymmetric monoclinic P21 space group. The crystal structure contains chains of edge-sharing distorted square planar [PdS4] units. The square-planar coordination of Pd in La6PdSi2S14 exhibits remarkable NLO properties with high SHG (3.7 × AgGaS2) and LDT (3 × AgGaS2) values as well as phase matchability. This shows the promise of novel materials with distorted structural motifs for enhanced NLO properties. Upon formation of bimetallic chiral sulfides containing both Cu and Pd, Cu occupies the opposite faces of the octahedra forming [CuS3] units while Pd can be stabilized in the center of PdS6 octahedra in the hexagonal P63 crystal structure of La6Pd0.5CuSi2S14. This suggests that it is possible to form mixed metal systems which could further enhance NLO properties by incorporation of additional structural distortions.

Preparation and third order nonlinear optical properties of corrole functionalized GO nanohybrids

Three novel corroles, 5,15-bis(phenyl)-10-(3-methoxy-4-hydroxylphenyl)- corrole PC, 5,15-bis(naphthyl)-10-(3-methoxy-4-hydroxylphenyl)-corrole NAPC and 5,15-bis(pyrenyl)-10-(3-methoxy-4-hydroxylphenyl)-corrole PYPC, were designed and synthesized. Their graphene oxide (GO) nanohybrids, PC-GO, NAPC-GO and PYPC-GO, were prepared by a covalent functionalization method and characterized by various spectroscopic techniques. The third order nonlinear optical (NLO) behavior of the corroles and their corresponding nanohybrids was investigated using open aperture Z-scan technique at 532 nm with 4 ns laser pulses. The nanohybrids showed enhanced NLO properties in comparison to the corresponding corroles. In addition, the NLO properties of nanohybrids increase in the order of NAPC-GO < PC-GO < PYPC-GO, while the corrole molecules exhibit NLO performance in the same order of NAPC < PC < PYPC, implying the NLO response originating from the corrole moiety play a more important role in the NLO properties of the nanohybrids than that arising from the photo-induced electron or energy transfer process between GO and corrole molecules. Importantly, at same transmission intensity, all the corroles showed typical nonlinear reverse saturation absorption (RSA) behavior, while all the nanohybrids exhibited a flip over behavior from saturation absorption (SA) to RSA. The different NLO response between the corrole molecules and their nanohybrids implies their promising applications as NLO materials.

“ZnS, an excellent material in photonics” - A review based on Z-scan study

Interest in the nonlinear optical properties of ZnS and the effects of alloying ZnS with other elements have been slowly increasing. Unlike ZnO, where tremendous work has been done, ZnS with similar properties is shadowed despite its prominent optical properties. Over the decade, ZnS has been successfully prepared using many techniques in its various forms such as nanoparticles, quantum dots, and thin films. Also, composite materials of ZnS have been developed to light on the enhancement in its properties. The possibility of tuning the properties of ZnS for the enhancement of nonlinear optical properties has been discussed by many reports. The suitability of ZnS for photonic device applications has been reviewed here using the Z-scan technique. Various methods of preparation, requirements, nonlinear behavior of various forms of ZnS in the past decade have been discussed in the present review article.

Intra-Molecular Electrical Field Regulated Nonlinear Catalyst Charge Transfer in the Organic Conjugated Molecular System

The application of organic conjugated molecular systems to photocatalysis is based on the charge transition with different electronegative substituents and the electron–hole separation behavior of charge transfer under light excitation. In this work, the relationship between the intra-molecular electrical field and molecular second-order nonlinear optical properties is investigated theoretically by the sum-of-states (SOS) method. We use substituents with different electron affinity energy to construct internal electric fields with different properties in similar conjugated systems. The studies of these systems reveal the intra-molecular electric field strength and mode regulation of nonlinear optical coefficients and explain its physical mechanism. The intra-molecular charge recombination caused by the electrostatic potential multipole field of different substituents changes the transition behavior of one-photon, resulting in the enhancement of nonlinear optical properties (second-harmonic generation and sum-frequency coefficient) greater than 104.

The Broadband Nonlinear Optical Response in Graphene/MoS2/Ag Thin Films at Near Infrared

Graphene/MoS2/Ag thin films were successfully prepared by the magnetron sputtering technique and liquid phase exfoliation. Structure, morphology, optical properties, and nonlinear optical characteristics of the graphene/MoS2/Ag and graphene/MoS2 thin films were studied by X-ray diffractometer, spectrophotometer, field-scanning electron microscope, and femtosecond (fs) Z-scan technique. The results of the fs Z-scan experiment indicate that the graphene/MoS2/Ag thin films exhibit reverse saturable absorption properties due to the free carrier absorption and two-photon absorption. More importantly, with the increase of DC magnetron sputtering power (from 5 to 15 W), the local surface plasmon resonance effect of the Ag thin films increases, which leads to the enhancement of nonlinear optical properties of the graphene/MoS2/Ag thin films. The nonlinear absorption coefficients of the graphene/MoS2/Ag thin films are increased from 1.14 × 10–10 to 1.8 × 10–10 m/W at 800 nm and from 4.79 × 10–11 to 6.79 × 10–11 m/W at 1,030 nm, and the nonlinear refraction index of the graphene/MoS2/Ag thin films is -4.37 × 10–17∼−4.18 × 10–16 m2/W under the excitation of 800 and 1,030 nm, respectively. Moreover, when the graphene/MoS2/Ag thin films were excited at 800 and 1,030 nm, respectively, the nonlinear figure of merit values of the graphene/MoS2/Ag thin films are increased from 1.23 to 2.91 and from 1.30 to 1.47, which are enough to support the application of the graphene/MoS2/Ag thin films in the field of all-optical switching applications.

Syntheses and nonlinear optical behavior of four-arm star-shaped phthalocyanine indium polymers containing azobenzene

In this report, a series of novel four-arm star-shaped polymethyl methacrylate with core of phthalocyanine indium polymers (InPc-(PMMAx)4) were achieved with different molecular weights through Activator ReGenerated by Electron Transfer Atom Transfer Radical Polymerization, using the synthesized phthalocyanine indium (InPc-Br) as initiator. The InPc-(PMMAx)4 polymers were characterized by NMR, FT-IR, GPC, UV–Vis and PL spectroscopy. The nonlinear optical (NLO) properties of InPc-(PMMAx)4 polymers were investigated by the Z-scan technique and it revealed that InPc-(PMMA16)4 obtained satisfactory NLO properties with imaginary third order susceptibility (Im[χ(3)]) of 16.4 × 10−12 esu. Furthermore, reacting polymer InPc-(PMMA16)4 with NaN3 and 1-(4-nitrophenyl)-2-(4-(prop-2-yn-1-yloxy) phenyl) diazene (Azo-yne) through click reaction, a novel InPc polymer InPc-(PMMA16-b-Azo)4 was successfully synthesized. InPc-(PMMA16-b-Azo)4 displayed a weak fluorescence at 707 nm compared to InPc-(PMMA16)4, demonstrating the energy transfer (ET) process between Azo and InPc, which could be proved by density functional theory. Because of the ET process, InPc-(PMMA16-b-Azo)4 exhibited a better NLO performance than InPc-(PMMA16)4, with Im[χ(3)] of 20.7 × 10−12 esu. In addition, the InPc-(PMMA16-b-Azo)4/PMMA complexes were prepared for the convenience of practical application, and it exhibited an excellent Im[χ(3)] value of 30.2 × 10−12 esu and a satisfactory limiting threshold of 0.04 J/cm2. The significantly enhanced NLO properties of InPc-(PMMA16-b-Azo)4/PMMA complexes demonstrate a weaker aggregation effect in polymethyl methacrylate matrix than in methyl methacrylate solution. Our study provides a promising design strategy to synthesize high performance NLO materials for practical applications.

Enhancement of nonlinear optical property of Cu2O/Ag/Cu2O composite films induced by laser irradiation

Enhancement of nonlinear optical property of Cu2O/Ag/Cu2O composite films induced by laser irradiation

Modulation of nonlinear optical properties in CdS based core shell nanocolloids fostered by metal nanoparticles

Synthesis of core–shell nanocomposites and exploration of its nonlinear optical properties is significant in the field of nanophotonics. Here we address the enhanced nonlinear optical properties of Ag/Au-CdS nanocolloids with Ag or Au as core and CdS as shell, synthesized by pulsed laser ablation. The composite nanocolloids were prepared by the ablation of metal targets immersed in CdS colloidal solution. The third order optical nonlinearities of Ag/Au-CdS core-shell nanoparticles (NPs) were studied using Z-scan technique. The studies reveal that the nonlinear absorption (NLA) of the prepared core–shell nanoparticles exhibits reverse saturable absorption (RSA) property and excellent optical limiting (OL) behavior as compared to their individual counterparts. An overall enhancement in the optical nonlinearities could be observed with the core-shell nanocolloids with the incorporation of metal NPs. Strong exciton plasmon interaction and the local field enhancement from the metal NPs are considered as the dominant mechanisms behind the enhanced NLO properties of core shell nanocolloids. The observed nonlinear optical (NLO) properties and the calculated nonlinear optical coefficients suggests that these nanocomposites could be applied for various photonic and optical limiting applications.

Static- and frequency-dependent NLO properties of dithienothiophene and thienothiophene bridges — A computational investigation

We have explored detailed linear and nonlinear optical properties of push-pull systems bearing thienothiophene and dithienothiophene spacers. By using density functional theory (DFT), frequency-dependent strategies were applied to examine the polarizability ([Formula: see text] and hyperpolarizability ([Formula: see text] and [Formula: see text]. The set of global and range-separated hybrid functionals with different Hartree–Fock (HF) exchange percentage at two basis sets cc-pVDZ and cc-pVTZ were used to evaluate the nonlinear optical (NLO) properties. The observed trends in the absorption maxima supported by perturbation potential analysis; as the absorption maxima increases, the respective amplitude potential decreases. For the investigated compounds, [Formula: see text]-conjugation along with the type of substituted acceptor plays a crucial role in the enhancement of NLO properties. The presence of acceptor group and length of conjugation increase between the D and A group; the first- and second-order intrinsic hyperpolarizability increases, leads to enhanced first- as well as second-order hyperpolarizability. Bond length alternation (BLA)/bond order alteration (BOA) exploration suggested that compounds attain cyanine limit. The trends in NLO properties for investigated compounds are supported by chemical reactivity descriptors, hardness and hyperhardness analysis. The polarizability is linearly correlated with the hyperpolarizability parameters ([Formula: see text] and [Formula: see text] and shows a good regression coefficient by figures of merit analysis.

Structural study of letrozole and metronidazole and formation of self-assembly with graphene and fullerene with the enhancement of physical, chemical and biological activities

Letrozole and metronidazole are two commonly used drugs for the management of breast cancer and parasitic infections, respectively. This manuscript attempts to study their structure, geometry, search for stable conformers using relaxed potential energy scan, spectral properties, quantum mechanical properties like energy and reactivity descriptors, intra molecular electron transfer properties, non-linear properties etc using various computational tools. It is found that these compounds will form a self-assembly with graphene sheets and fullerenes and exhibit a surface-enhanced Raman spectra and enhancement in non-linear optical properties when compared to the single molecule. The electronic absorption behavior of the compounds was studied using TD-DFT method. Global chemical reactivity descriptors and activity sites toward electrophilic and nucleophilic attack have been discussed. Studies of intra molecular electron transfer gave information about the relative stability of the compounds. Molecular docking studies indicate that the pure compounds and their self-assemblies with graphene have excellent biological activities. Communicated by Ramaswamy H. Sarma

Effect of 2,4-dinitrophenol dye doping on tristhioureazinc(II) sulfate single crystals: a potential nonlinear optical material

Good quality single crystals of 2,4-dinitrophenol (DNP)-doped tristhioureazinc(II) sulfate (ZTS) were successfully grown by employing the simple and cost effective slow-evaporation solution technique. To study the effect of doping on various device properties, the grown single crystals were subjected to powder X-ray diffraction (PXRD), high-resolution XRD, thermogravimetric analysis (TGA), Vickers hardness testing, and UV–visible, photoluminescence (PL) and Fourier transform IR (FTIR) spectroscopy techniques. The crystal structure of DNP-doped ZTS bulk single crystals remained the same as the crystal structure of ZTS. However, the changes in intensities of the diffraction peaks in the PXRD spectra indicated the incorporation of dopants into the crystalline matrix. FTIR studies confirm the incorporation of dopants into the crystalline matrix, shown by the shifting of certain prominent absorption bands towards higher energy. This also indicated the induced useful strain due to doping, leading to charge transfer and the enhancement of nonlinear optical properties. The cut-off wavelength and optical band gap energy of pure ZTS and DNP-doped ZTS crystals were studied by UV–visible absorption spectroscopy, revealing a slight reduction in the optical band gap energy due to doping, which in turn revealed the enhancement of the optical range. PL studies revealed an enhanced optical range of photoluminescence in ZTS crystals. Second harmonic generation (SGH) studies carried out by the Kurtz powder technique revealed the enhancement of SHG value due to DNP doping. To ensure the thermal stability and mechanical strength of the grown crystals with doping (required from the point of view of device applications), TGA and Vicker's hardness studies were performed.

Syntheses and characterizations of Zn (Ⅱ) Phthalocyanines & Naphthopyrans based polymers for improved nonlinear optical properties

In this paper, four organic polymers of poly [(MMA)x-co-(NPMA)y-co-(CPMA)z] and four zinc phthalocyanine (ZnPc) polymers of poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] have been successfully synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, where MMA is methyl methacrylate, NPMA is 3,3-diphenyl-8-methacryloxy-3H-naphtho [2,1-b]pyran, and CPMA is 3,4-dicyanophenyl methacrylate. The components of these polymers have been fully characterized by 1H and 13C NMR, FT-IR, Raman, XPS, UV–Vis, and photoluminescence (PL) spectroscopy. From PL spectra, poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] polymers display strong fluorescence quenching by the energy transfer (ET) process between NPMA and ZnPc moieties. The third-order nonlinear optical (NLO) properties of poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] polymers have been investigated by the Z-scan technique, and poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2] (Q4) showed the best NLO properties owing to the much stronger ET between NP and ZnPc units. Furthermore, it is essential to obtain doped poly (methyl methacrylate) (PMMA) films for practical application. The poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2]/PMMA film exhibited a higher nonlinear absorption coefficient of 61 × 10−11 m/W and a lower limiting threshold of 0.19 J/cm2. The significantly enhanced NLO properties of poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2]/PMMA film compared with solution are attributed to the weaker aggregation effect in PMMA film. This research provides a promising molecular design strategy for high performance NLO materials.

Novel axially substituted lanthanum phthalocyanines: Synthesis, photophysical and nonlinear optical properties

Materials with excellent nonlinear optical (NLO) properties are usually applied in optoelectronics and optical limiting devices. Photoinduced intramolecular electron transfer (PET) and energy transfer (ET) play an important role in enhanced NLO properties. Through axially connected anthraquinone to phthalocyanine, two types of novel lanthanum phthalocyanine (LaPc-Aqn and HLaPc-Aqn) were designed to effectively improve PET/ET process, and thus leading to excellent NLO properties. Hyperbranched phthalocyanines possess enhanced NLO properties owing to their special three-dimensional structures that have more donor–acceptor (D–A) systems in their cell structure than lanthanum phthalocyanines. The uniform polyphenylsulfone composite film(HLaPc-Aqn-PPSU) was prepared by a simple solution casting method according to the “like dissolves like” theory. The values of large third-order nonlinear susceptibility (Im[χ(3)]) and low limit threshold (Ilim) were 1.51 × 10−9 esu and 0.015 J/cm2, respectively, demonstrating that the film had great optical limiting performance. Such research can contribute to the development of novel phthalocyanine materials for nonlinear optics and optical limiting devices.