Third-order Optical Nonlinearity Research Articles

Chemically Modified Quinoidal Oligothiophenes for Enhanced Linear and Third-Order Nonlinear Optical Properties.

In the present investigation, quantum chemical calculations have been performed in a systematic way to explore the optoelectronic, charge transfer, and nonlinear optical (NLO) properties of different bis(dicyanomethylene) end-functionalized quinoidal oligothiophenes. The effect of different conformations (linking modes of thiophene rings) on conformational, optoelectronic, and NLO properties are studied from the best-performed dimer to octamer. The optical and NLO properties of all the selected systems (1–7) are calculated by means of density functional theory (DFT) methods. Among all the designed compounds, the largest linear isotropic (αiso) polarizability value of 603.1 × 10–24 esu is shown by compound 7 which is ∼12, ∼16, ∼9, ∼11, ∼10, and ∼4 times larger as compared to compounds 1–6, respectively. A relative investigation is performed considering the expansion in third-order NLO polarizability as a function of size and conformational modes. Among all the investigated systems, system 7 shows the highest value of static second hyperpolarizability ⟨γ⟩ with an amplitude of 7607 × 10–36 esu at the M06/6-311G** level of theory, which is ∼521, ∼505, ∼38, ∼884, ∼185, and ∼15 times more than that of compounds 1–6, respectively. The extensively larger ⟨γ⟩ amplitude of compound 7 with higher oscillator strength and lower transition energy indicates that NLO properties are remarkably dependent upon linking modes of thiophene rings and its chain length. Furthermore, to trace the origin of higher nonlinearities, TD-DFT calculations are also performed at the same TD-M06/6-311G** level of theory. Additionally, a comprehensive understanding of the effect of structure/property relationship on the NLO polarizabilities of these investigated quinoidal oligothiophenes is obtained through the inspection of Frontier molecular orbitals, the density of states (TDOS and PDOS), and molecular electrostatic potential diagrams including the transition density matrix. Hence, the current examination will not just feature the NLO capability of entitled compounds yet additionally incite the interest of experimentalists to adequately modify the structure of these oligothiophenes for efficient optical and NLO applications.

Optical, Electrochemical, Third-Order Nonlinear Optical Investigations of 3,4,5-Trimethoxy Phenyl Substituted Non-Aqueous Phthalocyanines.

A new series of non-aqueous phthalocyanines having 3,4,5-trimethoxy phenyl group at peripheral positions in which the central cavity possessing Cu(II), Zn(II), and without metals has been synthesized, and its absorption, fluorescence (steady-state and excited state lifetimes), electrochemical, and third-order nonlinear optical (NLO) properties were evaluated. Absorption studies data suggest that all three phthalocyanines obey Beer–Lambert’s law, and the redox properties indicate that both oxidation and reduction reactions are macrocyclic centered. The singlet quantum yields were measured in different solvents and were found to be in the range of 0.2–0.5 in the case of free-base, whereas it was in the range of 0.1–0.5 in zinc derivative, while the time-resolved fluorescence data revealed lifetimes of typically a few ns. The third-order NLO properties were investigated using the Z-scan technique with kilohertz (for retrieving true electronic nonlinearities) and megahertz repetition rate femtosecond pulses at 800 nm. Intensity-dependent Z-scan studies revealed robust NLO coefficients for solutions and thin films (two-photon absorption cross-sections of 9,300–57,000 GM) of these molecules suggesting a strong potential for optical switching, imaging, and optical limiting applications.

Synthesis, characterization and nonlinear optical response of polyelectrolyte-stabilized copper hydroxide and copper oxide colloidal nanohybrids

In the present work, the synthesis and characterization of polyelectrolyte-stabilized copper-based nanohybrids with tunable sizes and chemical composition are reported. More precisely, highly stable poly(sodium-4-styrenesulfonate) PSS-Cu(OH)2 and PSS-CuO/Cu(OH)2 nanohybrids are synthesized and characterized in terms of their chemical composition and morphology by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM) respectively. Moreover, their nonlinear optical (NLO) response is systematically investigated by means of the Z-scan technique under different excitation conditions, i.e., 50 fs, 800 nm and 4 ns, 532 nm laser pulses. The findings denote that the size and chemical composition of nanoparticles, defining the surface plasmon resonance frequency, along with the excitation laser parameters (pulse duration and wavelength) affect greatly the NLO response of these nanohybrids. To the best of our knowledge it is the first time that such copper-based nanohybrids are synthesized and investigated towards their third-order NLO response. The results suggest an efficient strategy for preparing copper hydroxide and copper oxide colloidal nanohybrids exhibiting at-will NLO properties for specific optoelectronic and photonic applications.

Pyrazines with terminal donor groups for third-order nonlinear optics: effect of graphene oxide on nonlinear absorption

Pyrazines with terminal donor groups for third-order nonlinear optics: effect of graphene oxide on nonlinear absorption

Experimental and computational study of naphthalimide derivatives: Synthesis, optical, nonlinear optical and antiviral properties

The nonlinear optical (NLO) and antiviral properties of naphthalimide Schiff base compounds (5a–c) were experimentally and computationally investigated. The synthesized compounds (5a–c) were successfully characterized via UV–Vis, FTIR, 1H NMR, fluorescence spectroscopy, and elemental analysis. The calculated average third-order NLO polarizabilities (˂γ˃) of 5a, 5b, and 5c were found to be 5, 9, and 21 times greater than the ˂γ˃ amplitude of p-NA, respectively. The computed results revealed the potential of the synthesized compounds for NLO applications. Additionally, molecular docking studies of the synthesized compounds with two crucial SARS-CoV-2 proteins were performed to examine their biochemical properties. Compound 5c exhibited a higher binding affinity with the spike protein compared to that with Mᴾᴿᴼ. The results obtained herein indicate the potential of the synthesized naphthalimide derivatives for optoelectronic and drug design applications.

Study of Third-order Nonlinear Optical Properties of Basic Violet 3 Dye in Polar Protic and Aprotic Solvents.

The present work aims to study of third-order nonlinear optical (TONLO) behavior of basic violet 3 dye dissolved in polar protic and aprotic solvents, namely, ethanol, 1-propanol, acetone and dimethyl sulfonate (DMSO), respectively. The polarity of the solvent used to have a substantial impact on the linear and TONLO properties of the dye sample. The dye exhibits self-defocusing nonlinearity due to thermally induced nonlinear refractive index and nonlinear absorption coefficient reveals the character of both saturable and reverse saturable absorption (RSA). The order of magnitude of nonlinear refractive index (n2) and nonlinear coefficient of absorption (β) of dye sample was determined to be 10-7 cm2/W and 10-3cm/W, respectively. The real and imaginary factors of the TONLO susceptibility of basic violet 3 dye were measured to be the power of 10-5 esu. The obtained results reveal that the dye sample seems to have the potential candidate for use in various photonics and optoelectronics applications.

Strong near-infrared and ultrafast femtosecond nonlinearities of a covalently-linked triply-fused porphyrin dimer-SWCNT nanohybrid

Functional materials displaying large ultrafast third-order optical nonlinearities across a wide spectral region and broad temporal domain are required for all-optical signal processing. Particularly desirable is nonlinear optical (NLO) activity at near-infrared (NIR) wavelengths with femtosecond pulses. Herein the first triply-fused porphyrin dimer (TFP)-functionalized single-walled carbon nanotube (SWCNT) nanohybrid was successfully constructed by covalently grafting TFPs onto SWCNT. The results of Z-scan techniques demonstrate that the newly obtained TFP-SWCNT nanohybrid was found with a strong NLO performance under both nanosecond and femtosecond irradiation. In the nanosecond regime, an enhancement in optical limiting (OL) of the TFP-SWCNT nanohybrid is seen at 532 nm when compared with the performance of porphyrin monomer-functionalized SWCNT nanohybrid Por-SWCNT. Under femtosecond irradiation, the TFP-SWCNT nanohybrid exhibits a particularly strong OL effect with a giant two-photon absorption (TPA) cross section value (ca. 15,500 GM) at 800 nm pulses that mainly stems from intense TPA of TFP, in sharp contrast to the Por-SWCNT nanohybrid which exhibits only saturable absorption under identical irradiation. These results demonstrate that the newly-developed TFP-SWCNT nanohybrid is a very promising OL candidate for practical applications across wide spectral and temporal domains, and that covalently functionalizing carbon-based materials with triply-fused chromophores may be a useful approach to engineering adaptable photonic devices with broad-ranging NLO activity.

High Harmonic Generation from Laser-Induced Plasmas of Ni-Doped CsPbBr3 Nanocrystals: Implications for Extreme Ultraviolet Light Sources

The development of versatile two-dimensional (2D) nanocrystals (NCs), with superior nonlinear optical (NLO) properties, is essential for various applications in photonics and optical communications. In this work, we demonstrate efficient high-order harmonic generation (HHG) from the laser-induced plasmas (LIPs) of CsPbBr3 and Ni-doped CsPbBr3 NCs. The present study has been directed at unraveling the role of dopants in the emission of intense harmonics from the LIP of purposefully engineered CsPbBr3 colloidal NCs. The trend observed in the harmonic yield enhancement is found to be similar to the increase in their third-order NLO properties [nonlinear refractive index (n2), nonlinear optical susceptibility (χ(3))] of the same NCs studied at a wavelength of 800 nm. Ni-doped CsPbBr3 NCs containing plasma spreading allowed optimization of the delay between nanosecond (ns) heating pulse and driving pulse (single-color pump) for an enhancement in the conversion efficiency of harmonics. We believe that the emission of harmonics from the LIPs of these pristine, Ni-doped CsPbBr3 colloidal 2D NCs reported here provides the means to address the increase in the efficiency of extreme ultraviolet radiation, useful in attosecond spectroscopic studies.

Electronic, reactivity and third order nonlinear optical properties of thermally-stable push-pull chalcones for optoelectronic interest: Experimental and DFT assessments

The present work highlighted the integration of quantum chemical approach and experimental results in attempts to elucidate the structural-property characteristics and behaviour of the fused-aromatic chalcones on the impact of their nonlinear attribute at the molecular level. Two push-pull chalcones namely 1-(anthracen-9-yl)-3(9-ethyl-carbazol-3-yl)prop-2-en-1-one (1AECP) and 3(9-ethyl-carbazol-3-yl)-1(pyren-1-yl)prop-2-en-1-one (3ECPP) were successfully designed, synthesised and analysed through FT-IR, UV–Vis, 1D NMR, TGA, DSC and third-order optical nonlinearities were performed via Z-scan measurement. Concurrently, density functional theory (DFT) analysis with basis set of B3LYP/6-31G (d,p) was computed to optimize the most stable molecular geometry configuration, HOMO-LUMO energy gap, global chemical reactivity descriptors (GCRD), molecular electrostatic potentials (MEP), natural bond orbital (NBO) analysis and hyperpolarizability analyses. The experimental optical gap (Egopt) of both compounds has demonstrated good agreement with corresponding calculated result and fall in the range of organic semiconducting materials with low range of HOMO-LUMO energy gap values, 2.98 and 2.74 eV respectively. The DFT result revealed that fused-aromatic reinforce intramolecular charge transfer (ICT), electronic dipole moment and improve polarizabilities on NLO properties of the material. The thermal stability analysis pinpointed that both of these materials are able to withstand high temperature up to 300 °C which unintentionally unveil their encouraging performance potentially. Additionally, Z-scan analysis discovered that both of the targeted compounds are indeed nonlinear refraction (NLR) active, manifesting self-defocusing effect with n2 value of −1.75 x 10−9 esu (1AECP) and −1.75 x 10−8 esu (3ECPP). In short, the theoretical output complement the experimental results fundamentally in the evaluation and prediction of their electronic nature which hence proved their prospect essentially in the optoelectronic-manufacturing development.

Integrated Si3N4 microresonator-based quantum light sources with high brightness using a subtractive wafer-scale platform.

The silicon nitride (Si3N4) platform, demonstrating a moderate third-order optical nonlinearity and a low optical loss compared with those of silicon, is suitable for integrated quantum photonic circuits. However, it is challenging to develop a crack-free, wafer-scale, thick Si3N4 platform in a single deposition run using a subtractive complementary metal-oxide-semiconductor (CMOS)-compatible fabrication process suitable for dispersion-engineered quantum light sources. In this paper, we demonstrate our unique subtractive fabrication process by introducing a stress-release pattern prior to the single Si3N4 film deposition. Our Si3N4 platform enables 950 nm-thick and 8 μm-wide microring resonators supporting whispering-gallery modes for quantum light sources at 1550 nm wavelengths. We report a high photon-pair generation rate of ∼1.03 MHz/mW2, with a high spectral brightness of ∼5×106 pairs/s/mW2/GHz. We demonstrate the first heralded single-photon measurement on the Si3N4 platform, which exhibits a high quality of conditional self-correlation gH(2)(0) of 0.008 ± 0.003.

The effect of synthesis situation on the structural, dielectric, linear and nonlinear optical properties of thiol-capped water-soluble lead sulfide (PbS) quantum dots

In this study, lead sulfide quantum dots (PbS QDs) have been prepared by an aqueous method with a mixture of TGL and DTG as a capping agent with different situations of synthesis. The XRD study defends mono-phase formation of PbS having a cubic system with a crystallite size of 2.9–3.6 nm. The SEM images show that the particles are at the nanoscale. The band gap energies of these samples were obtained 2.47–2.53 eV using UV–Vis absorption spectra. In addition, the optical limiting (OL) method was used to obtain linear absorption coefficient, α. The results of Kramers-Kronig (KK) relations show by increasing pH, the intensity increased in complex refractive index as well as complex dielectric constant. Moreover, regarding the transverse optical and longitudinal optical frequencies of PbS QDs, by increasing synthesized environment pH, both frequencies had significantly blue shifts. Owning the high dielectric constant of the sample, PbS QDs were revealed an appropriate candidate to employ in smart materials. Besides, standard single-beam Z-scan techniques with various laser powers have been employed for detecting nonlinear optical (NLO) characteristics. This research reports the relaxation time and pH-dependent third-order NLO properties of PbS QDs. The consequences have revealed that the nonlinear refractive (NLR) and nonlinear absorption (NLA) coefficients of PbS QDs have been improved by increasing laser power except at 55 mW, reaching values of 1.68 × 10−7 cm2/W and 6.8 × 10−4 cm/W in pH of 9.2 and relaxation time of 1 h at 45 mW, respectively.

Hirshfeld surface analysis, enrichment ratio, energy frameworks and third-order nonlinear optical studies of a hydrazone derivative for optical limiting applications

Organic materials with good third-order nonlinear optical (NLO) properties are used in optoelectronics for protecting human eyes and sensors from high intensity laser light. In this regard, herein we report the synthesis, structural analysis, and third-order NLO properties of an organic molecule N'-[(E)-(4-fluorophenyl)methylidene]biphenyl-4-carbohydrazide (FMBC) containing hydrazone moiety. The formation of the synthesized molecule is confirmed by identifying the functional groups through FTIR spectral analysis. The material possesses good thermal stability before the melting point of 242.5∘C and transparent in the entire visible region of the EM spectrum. The photoluminescence study revealed the blue light-emitting property of FMBC. The crystal structure is stabilized by N-H···O, C-H···O, and C-H···F hydrogen bond interactions. The interconnects in the crystal packing were envisioned quantitatively using Hirshfeld surfaces (HS) by 2D fingerprint plots. The main contribution to the HS comes mainly from C-H, H-H, and O-H interconnects which cover about 80 % of the total HS surface. The enrichment ratios show that the favorable contacts accountable for the crystal packing are C···H, N···H, O···H, and F···H. The breakdown of the interaction energies obtained for various molecular pairs shows the nature and strength of the interactions. The calculation of 3D energy frameworks suggests that contacts formed in the structure are largely due to the dispersion force followed by the electrostatic potential. Third-order NLO coefficients were extracted under the continuous wave (CW) regime using z -scan technique. The material is an excellent optical limiter with a threshold value of 3.42 kJ/cm2. [Display omitted]

Positional isomers of heterocyclic azo dyes: Investigation of NLO properties by Z-scan and correlative DFT studies

We report four azo dyes and their positional isomers having a benzothiazole-pyridone core. Selected heterocyclic emissive azo dyes in this work are analysed for their non-linear optical (NLO) properties. Non-linear absorptive coefficient (β), non-linear refractive index (ƞ2), third-order NLO susceptibility (χ3), and optical limiting (OL) in different solvents are analysed and promising results are obtained using Z-scan technique. Laser damage threshold (LDT) and thermogravimetric analysis (TGA) supports that these dyes can be a good constructive unit in laser assisted devices and several high-temperature NLO processes respectively. Molecular electrostatic potential (MEP), Frontier molecular orbitals (FMOs) are also presented using B3LYP/6–311+ G (d,p) level of theory. Global hybrid functional (GH) and Range separated hybrid functional (RSH) i.e. B3LYP, BHandHLYP and CAM-B3LYP, ωB97, ωB97X, ωB97X-D respectively used for the calculation of NLO parameters. Limits of hyperpolarizabilities and intrinsic hyperpolarizabilities are calculated and all the hyperpolarizabilities of the molecules are within estimated limits. HOMO-LUMO gap have an inverse correlation with the experimental non-linear optical susceptibility (χ3). Inverse or direct correlation with hyperpolarizability with different DFT descriptors such as electrophilicity index (ω), hyperhardness is also presented.

Enhanced optical properties of DNA-CTMA complex doped with [2.2]paracyclophane moieties

In this paper, the results of the research on linear and nonlinear optical properties of two organic molecules: 5-formyl-13-hydroxy[2.2]paracyclophane and 5-formyl-12-hydroxy[2.2]paracyclophane are presented and discussed. The studies were performed on both thin films and solutions. Thin films were obtained by spin deposition of the studied solutions molecules in DNA-CTMA matrix. Such properties like: optical absorption, fluorescence and third-order nonlinear optical (NLO) susceptibilities were determined. The molecules exhibit large transparency range in visible and an enhancement of third order NLO susceptibility at 1064.2 nm fundamental wavelength. An important χ(3) increase, ca. 50%, is observed when changing the OH substitution from para to ortho. The fluorescence measurements have shown the presence of a broad emission band in visible, well separated from the optical absorption.

Third-Order Nonlinear Optical Behavior of an Amide-Tricarboxylate Zinc(II) Metal-Organic Framework with Two-Fold 3D+3D Interpenetration.

A new metal-organic framework (MOF), [Zn4(μ4-O)(μ6-L)2(H2O)2]n·nDMF (ZSTU-10), was assembled from zinc(II) nitrate and N,N',N″-bis(4-carboxylate)trimesicamide linkers and fully characterized. Its crystal structure discloses an intricate two-fold 3D+3D interpenetrated MOF driven by the [Zn4(μ4-O)]-based tetragonal secondary building units and the C3-symmetric tris-amide-tricarboxylate linkers (μ6-L3-). Topological analysis of ZSTU-10 reveals two interpenetrated 3,6-connected nets with an rtl (rutile) topology. Z-Scan analysis at 532 nm was conducted to study a nonlinear optical (NLO) behavior of ZSTU-10. The nonlinear responses of ZSTU-10 were explored under various laser intensities, revealing notable third-order NLO properties in the visible region. A large two-photon absorption at lower incident intensities highlights the fact that ZSTU-10 can be applied in optical limiting devices as well as optical modulators. Moreover, a nonlinear refractive index (n2) is indicative of a self-defocusing behavior. This work thus expands a family of novel MOF materials with remarkable optical properties.

Ultrafast Third-Order Nonlinear Optical Response Excited by fs Laser Pulses at 1550 nm in GaN Crystals.

The ultrafast third-order optical nonlinearity of c-plane GaN crystal, excited by ultrashort (fs) high-repetition-rate laser pulses at 1550 nm, wavelength important for optical communications, is investigated for the first time by optical third-harmonic generation in non-phase-matching conditions. As the thermo-optic effect that can arise in the sample by cumulative thermal effects induced by high-repetition-rate laser pulses cannot be responsible for the third-harmonic generation, the ultrafast nonlinear optical effect of solely electronic origin is the only one involved in this process. The third-order nonlinear optical susceptibility of GaN crystal responsible for the third-harmonic generation process, an important indicative parameter for the potential use of this material in ultrafast photonic functionalities, is determined.

Discussion on structural, optical, thermal, mechanical, dielectric and third-order NLO properties of 3-Nitroanilinium chloride single crystals for optoelectronic applications

Preferable, third-order nonlinear optical (NLO) single crystal, 3-Nitroanilinium chloride (3NACL) was auspiciously synthesised by slow evaporation technique. The crystal system of the synthesised 3NACL crystal was triclinic with centrosymmetric space group \({\text{P}}\bar{1}\) was identified by single-crystal XRD studies. All the functional groups present in the sample and its respective vibrations were analysed through FTIR analysis. UV–Vis transmittance spectrum revealed that the synthesised material showed 83% transmittance and its cut-off wavelength was 281 nm. The mechanical stability and thermal property of the grown 3NACL crystals were ascertained by Vickers microhardness analysis and TG/DTA analysis. The intermolecular interaction of the 3NACL was scrutinized by Hirshfeld surface analysis. Dielectric studies revealed that dielectric constant and dielectric loss were high at lower frequency region due to the space charge polarization. Inclusion-free 3NACL crystal was used to analyse the Laser damage threshold (LDT) studies and its calculated LDT value was 4.3 GW/cm2. The third-order NLO parameters (β = 7.5472 × 10–12 m/W, η2 = 5.6931 × 10–19 m2/W, χ3 = 2.9491 × 10–13 esu) of the 3NACL material were statutorily evaluated by Z-scan studies. Here, β and η2 were positive, due to the saturated absorption and self-focusing effect as observed in open and closed aperture z-scan curve. Above all these findings, 3NACL was a suitable material for NLO and optoelectronic applications.

Ultrafast two-photon optical switch using single crystal hybrid halide perovskites

Photoelectronic performance of organic–inorganic hybrid perovskites has been investigated extensively. Advancement in optoelectronic characterization and application of this group of materials in solar cells, light-emitting diodes, and lasers has been pushed forward rapidly. However, nonlinear optical properties for applications in optical logic devices have not been exploited. Moreover, long-lived excitons and charges limit the response speed of such materials and further construction of ultrafast devices. In this work, we make use of the high third-order optical nonlinearity of ( C H 3 N H 3 ) P b B r 3 single crystals and develop a femtosecond optical switch (OS) based on strong two-photon processes through absorbing one pump and one probe photon. The fascinating band structure, with a steep edge at 2.22 eV between the transmission and strong absorption bands, endows single crystals of ( C H 3 N H 3 ) P b B r 3 with perfect characteristics for two-photon optical switching in the near infrared. An on–off ratio of the probe pulses of about 90% and a speed faster than 400 fs have been achieved for this OS device. To the best of our knowledge, such high efficiency has not been realized for an ultrafast OS with any other materials and devices. Moreover, this is a first exploration, to our best knowledge, of the third-order optical nonlinearity of organic–inorganic hybrid halide perovskites for application in ultrafast optical logic devices with high reliability and low threshold in the near infrared.

Effect of the thermal–optical nonlinearity on optical trapping Rayleigh particles

In femtosecond-pulsed optical tweezers, the high peak intensity of each laser pulse results in the instantaneous trapping of a particle, while the high-repetition-rate ensures the repetitive trapping of a particle by pulse trains. Therefore, the high peak intensity and high-repetition-rate inevitably lead to the third-order optical nonlinearity and the thermal–optical nonlinearity, respectively. Herein, we investigate the optical forces on the Rayleigh particle using a high-repetition-rate femtosecond-pulsed Gaussian beam when the Kerr nonlinearity and thermal–optical nonlinearity are considered simultaneously. With the help of thermally induced nonlinearity of the surrounding medium to change the relative refractive index of particles, the three-dimensional stable trapping of slightly low-refractive-index particles is realized by the use of high-repetition-rate femtosecond-pulsed Gaussian beams. Besides, we study the influence of thermal–optical nonlinearity on optical trapping of high-refractive-index particles. It is shown that the trapping stiffness increases nonlinearly with the increase of power due to the thermal–optical​ nonlinearity. This work opens up the possibility of trapping the low-refractive-index beyond the linear optics regime, successfully explains the reported experimental observations, and provides the theoretical support for tapping nonlinear optical particles in femtosecond optical tweezers.

Two-Dimensional Bismuthene Showing Radiation-Tolerant Third-Order Optical Nonlinearities.

The ever-increasing space exploration enterprise calls for novel and high-quality radiation-resistant materials, among which nonlinear optical materials and devices are particularly scarce. Two-dimensional (2D) materials have shown promising potential, but the radiation effects on their nonlinear optical properties remain largely elusive. We previously fabricated 2D bismuthene for mode-locking sub-ns laser; herein, their space adaption was evaluated under a simulated space radiation environment. The as-synthesized thin layers of bismuthene exhibited strong third-order nonlinear optical responses extending into the near-infrared region. Remarkably, when exposed to 60Co γ-rays and electron irradiation, the bismuthene showed only slight degradation in saturable absorption behaviors that were critical for mode-locking in space. Ultrafast spectroscopy was applied to address the radiation effects and damage mechanisms that are difficult to understand by routine techniques. This work offers a new bottom-up approach for preparing 2D bismuthene, and the elucidation of its fundamental excited-state dynamics after radiation also provides a guideline to optimize the material for eventual space applications.