Dynamic Optical Properties Research Articles

Microfluidic wet spinning of soft polydimethylsiloxane polymer optical fibers

Polymer optical fibers (POFs) are an essential component of photonic textile sensors for the development of healthcare@home technologies. However, fabricating tailored POFs exhibiting the required properties for such applications remains challenging. Here, an innovative method to fabricate soft POFs based on polydimethylsiloxane is introduced: the hydrogel-assisted microfluidic wet spinning (HA-MWS) technology. Combined with a straightforward post-processing step, the HA-MWS enabled the production of soft POFs with tailored moduli (0.35 MPa to 5.0 MPa), low surface roughness (Rq< 6 nm), and, consequently, low attenuation (<0.25 dB/cm). The quasi-static and dynamic mechanical, chemical, optical, thermal, and surface properties of the soft POFs produced by HA-MWS were investigated in detail. A photonic textile sensor demonstrator was built with these soft POFs with tailored pressure sensitivity in the range of 2–300 kPa, modulus close to that of skin, and high-temperature stability between -30C∘ and 90C∘. This methodology can potentially become a standard tool for designing POFs with tunable properties for healthcare monitoring, soft robotics, and biomedicine applications.

Theoretical investigation into saline optical properties for enhancing solar still performance: Mathematical modeling approach

This study investigates the dynamic optical properties of saline solutions, specifically transmissivity, absorptivity, and reflectivity, and their impact on the performance of solar stills. This research addresses the critical challenge of enhancing freshwater production through solar desalination, which is vital in water-scarce regions. Utilizing a validated mathematical model, the study examines how variations in saline depths (ranging from 5 mm to 40 mm), nanofluids, chemical additives, and dyes influence the optical properties and efficiency of solar stills. The results show that a depth of 20 mm emerges as optimal, providing a balance between high transmissivity, absorptivity, and low reflectivity, also a higher saline absorptivity, ranging from 0.014 to 0.021, significantly boosts solar still performance, while transmissivity, ranging from 0.26 to 0.95, affects instantaneous efficiency. The study reveals that the production of distilled water decreases from 6.77 to 4.87 L/m2 as the refractive index increases from 1.2 to 2.6, while higher extinction coefficients enhance production, reaching up to 6.96 L/m2 at 300 m−1. These findings demonstrate the importance of optimizing saline optical properties to improve solar still efficiency. The novelty of this work lies in its comprehensive analysis of the dynamic nature of saline optical properties and their practical application in enhancing solar desalination technology, going beyond previous efforts that assumed constant optical properties. This advanced understanding significantly contributes to the development of more efficient and effective solar desalination systems.

Piezofluorochromism in Covalent Organic Frameworks: Pressure-Induced Emission Enhancement and Blue-Shifted Emission.

Achieving enhanced or blue-shifted emission from piezochromic materials remains a major challenge. Covalent organic frameworks (COFs) are promising candidates for the development of piezochromic materials owing to their dynamic structures and adjustable optical properties, where the emission behaviors are not solely determined by the functional groups, but are also greatly influenced by the specific geometric arrangement. Nevertheless, this area remains relatively understudied. In this study, a successful synthesis of a series of bicarbazole-based COFs with varying topologies, dimensions, and linkages was conducted, followed by an investigation of their structural and emission properties under hydrostatic pressure generated by a diamond anvil cell. Consequently, these COFs exhibited distinct piezochromic behaviors, particularly a remarkable pressure-induced emission enhancement (PIEE) phenomenon with a 16-fold increase in fluorescence intensity from three-dimensional COFs, surpassing the performance of CPMs and most organic small molecules with PIEE behavior. On the contrary, three two-dimensional COFs with flexible structures exhibited rare blue-shifted emission, whereas the variants with rigid and conjugated structures showed common red-shifted and reduced emission. Mechanism research further revealed that these different piezochromic behaviors were primarily determined by interlayer distance and interaction. This study represents the first systematic exploration of the structures and emission properties of COFs through pressure-treated engineering and provides a new perspective on the design of piezochromic materials.

Piezofluorochromism in Covalent Organic Frameworks: Pressure‐Induced Emission Enhancement and Blue‐Shifted Emission

AbstractAchieving enhanced or blue‐shifted emission from piezochromic materials remains a major challenge. Covalent organic frameworks (COFs) are promising candidates for the development of piezochromic materials owing to their dynamic structures and adjustable optical properties, where the emission behaviors are not solely determined by the functional groups, but are also greatly influenced by the specific geometric arrangement. Nevertheless, this area remains relatively understudied. In this study, a successful synthesis of a series of bicarbazole‐based COFs with varying topologies, dimensions, and linkages was conducted, followed by an investigation of their structural and emission properties under hydrostatic pressure generated by a diamond anvil cell. Consequently, these COFs exhibited distinct piezochromic behaviors, particularly a remarkable pressure‐induced emission enhancement (PIEE) phenomenon with a 16‐fold increase in fluorescence intensity from three‐dimensional COFs, surpassing the performance of CPMs and most organic small molecules with PIEE behavior. On the contrary, three two‐dimensional COFs with flexible structures exhibited rare blue‐shifted emission, whereas the variants with rigid and conjugated structures showed common red‐shifted and reduced emission. Mechanism research further revealed that these different piezochromic behaviors were primarily determined by interlayer distance and interaction. This study represents the first systematic exploration of the structures and emission properties of COFs through pressure‐treated engineering and provides a new perspective on the design of piezochromic materials.

Influence of substituent at the para position of tetraphenylethylene on static and dynamic nonlinear optical properties: In-silico approach

In this study, tetraphenylethylene (TPE) derivatives with various substituents (F, OH, OMe, CN, NO2, and NO) at the para position were selected for the non-linear optical properties. Non-centrosymmetric behavior and charge distribution of these derivatives were evaluated using natural bond orbital (27.24 kcal/mol orbital interaction energy in case of πC6-C10 → π*N46-O47 for TPE-NO), HOMO-LUMO diagrams, and molecular electrostatic potential analyses (OH, 34.15 kcal/mol and CN, −35.39 kcal/mol). TPE derivatives with electron-withdrawing groups displayed higher hyperpolarizability values (molecular, time and frequency dependent values) compared to electron-donating ones. TPE-NO have shown highest values for static (52.73 × 10-30 esu) and molecular (288.43 × 10-30 Debye.esu). TPE with withdrawing groups showed higher limit of first order hyperpolarizability ranging from 1050 × 10-30 to 1530 × 10-30 esu. βHRS1064 >βHRS1340 >βHRS1460 > βHRS1907 and βTD1064 <βTD1340 <βTD1460 < βTD1907 are the order of computed Hyper-Rayleigh scattering and time-dependent first order dynamic hyperpolarizability respectively.

Dynamic Color Regulation of the Lycaenid Butterfly Wing Scales

Butterfly coloration originates from the finely structured scales grown on the underlying wing cuticle. Most researchers who study butterfly scales are focused on the static optic properties of cover scales, with few works referring to dynamic optical properties of the scales. Here, the dynamic coloration effect of the multiple scales was studied based on the measurements of varying-angle reflection and the characterization of scale flexibility in two species of Lycaenid, Plebejus argyrognomon with violet wings and Polyommatus erotides with blue wings. We explored the angle-dependent color changeability and the color-mediating efficiency of wing scales. It was found that the three main kinds of flexible scales (cover, ground and androconia scales) were asynchronously bent during wing rotation, which caused the discoloration effect. The three layers of composite scales broaden the light signal when compared to the single scale, which may be of great significance to the recognition of insects. Specifically, the androconia scales were shown to strongly contribute to the overall wing coloration. The cover scale coloration was ascribed to the coherence scattering resulted from the short-range order at intermediate spatial frequencies from the 2D Fourier power spectra. Our findings are expected to deepen the understanding of the complex characteristics of biological coloration and to provide new inspirations for the fabrication of biomimetic flexible discoloration materials.

Superalkali nature of the Si9M5 (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties.

Zintl clusters have attracted widespread attention because of their intriguing bonding and unusual physical properties. We explore the Si9 and Si9M5 (where M = Li, Na, and K) Zintl clusters using the density functional theory combined with other methods. The exothermic nature of the Si9M5 cluster formation is disclosed, and the interactions of alkali metals with pristine Si9 are shown to be noncovalent. The reduced density gradient analysis is performed, in which increased van der Waals interactions are observed with the enlargement of the size of alkali metals. The influence of the implicit solvent model is considered, where the hyperpolarizability (βo) in the solvent is found to be about 83 times larger than that in the gas phase for Si9K5. The frequency-dependent nonlinear optical (NLO) response for the dc-Kerr effect is observed up to 1.3 × 1011 au, indicating an excellent change in refractive index by an externally applied electric field. In addition, natural bonding orbitals obtained from the second-order perturbation analysis show the charge transfer with the donor-acceptor orbitals. Electron localization function and localized orbital locator analyses are also performed to better understand the bonding electrons in designed clusters. The studied Zintl clusters demonstrate the superalkali character in addition to their remarkable optical and nonlinear optical properties.

Photoswitching the fluorescence of nanoparticles for advanced optical applications.

The dynamic optical response properties and the distinct features of nanomaterials make photoswitchable fluorescent nanoparticles (PF NPs) attractive candidates for advanced optical applications. Over the past few decades, the design of PF NPs by coupling photochromic and fluorescent motifs at the nanoscale has been actively pursued, and substantial efforts have been made to exploit their potential applications. In this perspective, we critically summarize various design principles for fabricating these PF NPs. Then, we discuss their distinct optical properties from different aspects by highlighting the capability of NPs in fabricating new, robust photoswitch systems. Afterwards, we introduce the pivotal role of PF NPs in advanced optical applications, including sensing, anti-counterfeiting and imaging. Finally, current challenges and future development of PF NPs are briefly discussed.

Photovoltaic properties of halide perovskites for solar cell application with efficiency greater than 18.

The opto-electronic properties and solar cell efficiency of halide perovskites A2LiInBr6 (A = Rb, Cs) are investigated using density functional theory (DFT) through WEIN2k and SCAPS-1D. The electronic characteristic of A2LiInBr6 (A = Rb, Cs) compounds reveal their direct bandgap semiconductor nature and are active in visible rang. The results indicate that substituting Cs with Rb causes a slight narrowing of the bandgap. According to the optical analysis, these compounds possess dynamic visible-range optical properties that make them ideal for application in opto-electronic devices and solar cells. The A2LiInBr6 (A = Rb, Cs) absorber layer is employed to simulate the solar cell efficiency of these lead free perovskite-based device. The optimized FTO/WS2/A2LiInBr6 (A = Rb, Cs)/Spiro-MeOTAD/Cu solar cells exhibit the best performance with WS2 as the ETL and Spiro-MeOTAD as the HTL having V oc value of 2.27 V and 1.85 V, J sc value is 11.35 and 11.44 mA cm-2, FF is 73.24% and 83.84%, PCE is 18.88% and 17.97%, R s is 9.94 and 4.88 Ω cm2 and R sh is 1.35 and 1.14 Ω cm2 respectively. As a result, this research paves the way for future experiments to create entirely inorganic perovskite photovoltaics, free of lead toxicity and exhibit improved photovoltaic ability.

Stimuli‐responsive active materials for dynamic control of light field

AbstractThe increasing demand for the multidimensional and dynamic control of light has spurred the development of stimuli‐responsive, reconfigurable, and programmable optical systems. Liquid crystals (LCs), which combine liquid‐like stimuli‐responsiveness and crystal‐like orientational ordering, have emerged as highly appealing soft materials. Owing to their exceptional optical performance and programmable functionalities, they are becoming incredibly important materials in active planar optics and photonics. Additionally, silk proteins, luminescent materials, and metasurfaces exhibit dynamic optical properties, enabling remarkable multifunctional applications. This review focuses on the advancements in stimuli‐responsive materials, including LCs, silk proteins, luminescent materials, and active metasurfaces as well as some of these materials paired with LCs. Their attractive tunable applications in optics and photonics, along with the great potential for the future development of active optical systems, are also emphasized.

DFT molecular simulations for static, dynamic and solvent-dependent nonlinear optical properties of triphenylamine-carbazole-based organic dyes with D-D-A framework

Nonlinear optical (NLO) materials are vital for advancing cutting-edge optoelectronic technology. Herein, triphenylamine-carbazole-based organic dyes with a D-D-A framework are quantum chemically designed with acceptor modifications, and their geometric, electronic, static, dynamic, and solvent-dependent NLO properties are explored using density functional theory (DFT) simulations. The IEFPCM model is employed to investigate the solvent effect on the NLO properties of proposed compounds (BSA-1 to BSA-9). Interestingly, the dipole moment (μtot), average linear polarizability (αtot), and first hyperpolarizability (βtot) were determined for all proposed compounds in gas phase and water (ε = 78.36), DMSO (ε = 46.83), methanol (ε = 32.61), tetrahydrofuran (ε = 7.43), chloroform (ε = 4.71), and benzene (ε = 2.27) solvents. Natural population analysis (NPA), transition density matrix (TDM), UV–Vis investigation, frontier molecular orbital (FMO), and topological analysis (MEP, ELF, and LOL) were carried out to explain the NLO findings. The topological study suggests that BSA and BSA-1 to BSA-9 are chemically active and may have NLO implications. Moreover, the findings demonstrate that BSA-9 is the most promising second-order NLO candidate because of the highest λmax (418.60 nm) in dichloromethane (DMF) and the lowest energy gap (1.49 eV) among all the derivatives. It was found that BSA-2 and BSA-9 demonstrated the giant static αo (7.26 × 102) and βo (9.91 × 104) values among the proposed compounds for use in a wide range of solvent-dependent NLO applications. The solvent effect on NLO in all proposed compounds is noticeable, especially in BSA-9, which exhibited βo = 1.89 × 105 in benzene, 2.80 × 105 in THF, 3.21 × 105 in methanol, 3.25 × 105 in DMSO and 3.28 × 105 in water. Furthermore, Electro-optical Pockels effect (EOPE) β(-ω,ω,0) and the second harmonic generation (SHG) β(-2ω,ω,ω) results computed at ω = 532 nm (0.0856 au) and ω = 1064 nm (0.0428 au) frequencies confirm that all proposed compounds are excellent NLO candidates and should be targeted for future static, frequency-dependent and solvent-dependent NLO applications.

Performance of density functional theory for calculating the electronic, static, and dynamic nonlinear optical properties of asymmetric (3E,5E)-3,5-dibenzylidene-piperidin-4-one derivatives

Performance of density functional theory for calculating the electronic, static, and dynamic nonlinear optical properties of asymmetric (3E,5E)-3,5-dibenzylidene-piperidin-4-one derivatives

Design and performance investigation of a novel self-adaptive radiative cooling module for thermal regulation in buildings

Daytime radiative cooling utilizes the process of reflecting sunlight and radiating heat through the atmospheric transparent window (8–13 μm) to achieve spontaneous cooling of an object. However, the existing challenge lies in the disparity between the cooling supply and demand, necessitating the development of self-regulating radiative cooling. This study introduces a novel design that combines paraffin wax with a radiative cooler, leading to the development of a self-adaptive radiative cooler (SRC) with two distinct modes based on dynamic optical properties. The spectral properties of the four SRCs were calculated by Fresnel equation, and it was found that the SRC possessed the ability to optimally absorb solar energy (Δα = 0.322) and automatically adjusted their thermal emittance (Δε = 0.552) in response to ambient temperature changes, facilitated by the liquid-solid transition, especially for Case 1. Therefore, the novel SRCs demonstrate a unique behaviour: they are warmer than static radiative coolers (ΔT = 3 K) in cold ambient conditions, while maintaining high cooling power in hot environments. Through extensive simulations for various cities and climates, this study demonstrates the superior energy-saving performance of the SRCs in building thermal regulation compared to that of static radiative coolers (Δδ1 = 9.6%).

The stability, electronic, thermal, and optical properties of silver halide (AgX: X = F, Cl, Br, and I) semiconductors: Ab-initio study

The structural properties, mechanical and dynamic stability, electronic, thermal and optical properties of silver halide AgX (X = F, Cl, Br, and I) compounds in the rock-salt phase within GGA and HSE approximations have been studied. The calculations are performed using the QUANTUM-ESPRESSO package which is based on the density functional theory (DFT) and the pseudo-potential method. The calculated elasticity parameters illustrated that the rock-salt phase complies with the mechanical stability conditions at ambient pressure. Based on the results of the mechanical calculations, it can be concluded that AgI is more rigid than other silver halide compounds, while the AgF compound is more malleable than other silver halide compounds. Also, against other examined silver halides, the AgI compound has an isotropic nature. The phonon scattering diagram has proved the dynamic stability of silver halide compounds in the studied rock-salt phase. Evaluation of the electronic results indicates that silver halide compounds in both GGA and HSE approximations have an indirect bandgap in the L−Γ path. In comparison to GGA, the HSE calculation improves the amount of bandgap toward a better agreement with experimental results. At room temperature, the hole mobility of silver halides is much less than the electron mobility. The decreasing trend of the effective mass of electrons in silver halides with the atomic radius of halide in the rock-salt phase leads to a faster carrier transfer rate in AgI, AgBr, AgCl, and AgF compounds, respectively. Moreover, by increasing the atomic radius of halide atom X, the Debye temperature θD and stiffness decrease, and inversely the heat capacity Cv increases. The increasing entropy relative to temperature refers to the endothermic properties of silver halide compounds. In both GGA and HSE approximations, the AgF compound has the highest absorption coefficient peak with the maximum optical absorption in the ultraviolet regime of the electromagnetic spectrum. The absorption coefficients of the silver halide compounds are of the order of 105 cm−1 which is comparable to the absorption coefficient of silicon crystals. The latter property along with a high stability and high electron mobility, makes silver halides attractive photocatalytic materials in the NaCl structure.

Ab initio calculated dynamic structural factors and optical properties of beryllium along the Hugoniot

Beryllium is an ablator material used in inertial-confinement fusion and hypervelocity impact studies. The thermoelastic properties, structural factors, and optical properties of beryllium are important in these studies. In this paper, the static structural factors, ion–ion dynamic structural factors, adiabatic velocity, and optical properties of beryllium along the Hugoniot were calculated by ab initio simulations. The static structural factors show that beryllium atoms were randomly distributed. The dynamic structural factors extracted the dispersion relation for collective excitation via the scattering function. By collecting the peak position of the dynamic structural factors, the dispersion relation and adiabatic sound velocity were derived by definition. Using the calculated equation of state, the thermoelastic properties and adiabatic sound velocity have been derived. The two calculated methods for adiabatic sound velocity were verified to be equivalent.

Interactive Stratospheric Aerosol Microphysics‐Chemistry Simulations of the 1991 Pinatubo Volcanic Aerosols With Newly Coupled Sectional Aerosol and Stratosphere‐Troposphere Chemistry Modules in the NASA GEOS Chemistry‐Climate Model (CCM)

AbstractWe have coupled the GEOS‐Chem tropospheric‐stratospheric chemistry mechanism and the Community Aerosol and Radiation Model for Atmospheres (CARMA), a sectional aerosol microphysics module, within the NASA Goddard Earth Observing System Chemistry‐Climate Model (GEOS CCM) in order to simulate the interactions between stratospheric chemistry and aerosol microphysics. We use observations of the 1991 Mount Pinatubo volcanic cloud to evaluate this new version of the GEOS CCM. The GEOS‐Chem chemistry module is used to simulate the oxidation of sulfur dioxide (SO2) more realistically than assuming hydroxyl radical (OH) fields are constant, as OH concentrations in the plume decrease dramatically in the weeks following the eruption. CARMA simulates sulfate aerosols with dynamic microphysical and optical properties. The CARMA‐calculated aerosol surface area is coupled to the chemistry module from GEOS‐Chem for the calculation of heterogeneous chemistry. We use a set of observational and theoretical constraints for Pinatubo to evaluate the performance of this new version of the GEOS CCM. These simulations are specifically compared with satellite and in‐situ observations and provide insights into the connections between the gas‐phase chemistry and the aerosol microphysics of the early plume and how they impact the climatic and chemical changes following a large volcanic eruption. A second, smaller eruption is also included in these simulations, the 15 August 1991, eruption of Cerro Hudson in Chile, which we find essential in explaining the aerosol optical depth in the Southern Hemisphere in 1991.

Transient simulation of laser ablation based on Monte Carlo light transport with dynamic optical properties model

Laser ablation is a minimally invasive therapeutic technique to denature tumors through coagulation and/or vaporization. Computational simulations of laser ablation can evaluate treatment outcomes quantitatively and provide numerical indices to determine treatment conditions, thus accelerating the technique’s clinical application. These simulations involve calculations of light transport, thermal diffusion, and the extent of thermal damage. The optical properties of tissue, which govern light transport through the tissue, vary during heating, and this affects the treatment outcomes. Nevertheless, the optical properties in conventional simulations of coagulation and vaporization remain constant. Here, we propose a laser ablation simulation based on Monte Carlo light transport with a dynamic optical properties (DOP) model. The proposed simulation is validated by performing optical properties measurements and laser irradiation experiments on porcine liver tissue. The DOP model showed the replicability of the changes in tissue optical properties during heating. Furthermore, the proposed simulation estimated coagulation areas that were comparable to experimental results at low-power irradiation settings and provided more than 2.5 times higher accuracy when calculating coagulation and vaporization areas than simulations using static optical properties at high-power irradiation settings. Our results demonstrate the proposed simulation’s applicability to coagulation and vaporization region calculations in tissue for retrospectively evaluating the treatment effects of laser ablation.

Ultrafast dynamic processes and nonlinear optical properties of Platinum(II) fluoren-acetylides

Two N-(4-ethylnylphenyl)-9H-fluoren-9-imine (EFT)arylacetylides (1, 2) and three EFT based Platinum(II) arylacetylides (3, 4, 5) were synthesized. The ultrafast dynamic processes after excitation and the nonlinear optical properties for picosecond lasers were investigatedusing femtosecond transient absorption and Z-scan techniques. The influence of conjugated length and Pt(II) content percentage on the properties ofthese moleculeswas discussed in detail. For compounds 1 and 2, two dynamic decay processes are observed after excitationby the pump laser beams. The first process is an ultrafast singlet (first singlet excited state, S1S*) → singlet state (ground state, GS), followed by a geometric twisting charge transfer state (CTS*) of the fluoren units relative to the central arylacetylide plane. For 3, 4, and 5, three dynamic decay processes are observed. The first process is the same as those of 1 and 2. However,the geometric twisting of 3, 4, and 5 is easier than 1 and 2 due to the presence of Pt atoms in the molecular skeleton of 3, 4, and 5, which makes a fast S1S* → geometric twisting state (TS*) occurred before the charge transfer occurring, and then a subsequent geometric twisting state (TS*) to geometric twisting charge transfer state (CTS*) occurs. The nonlinear optical properties of these compounds, studied using the open aperture Z-scan technique (λ = 532 nm, pulse width 23 ps), show that the values of the title compounds are around tens of cm/GW, which are comparable to newly reported porphyrin-based MOF materials and much better than Ru(II) terpyridine complexes..The mechanism of the nonlinear optical properties is attributed to the excited state absorption based on S1S*, TS*, and CTS* states, according to the femtosecond transient absorption and Z-scan results. The increase of Pt content percentage does not benefit the nonlinear absorption of Pt-containing compounds for the picosecond pulse laser. This is because the increase of the intersystem crossing rate weakly contributes to the nonlinear optical properties.

Strain tuning of the electronic structure and optical properties of novel Janus MgBrI monolayer: Insights from first-principles calculations

Using first-principles calculations in the framework of density functional theory (DFT), we systematically carry out the dynamic stability, electronic and optical properties of the Janus MgBrI monolayer and its parent MgI2 and MgBr2 monolayers. Our findings show that these systems have no imaginary frequencies in the entire Brillouin zone (BZ), which means they are very stable. At the equilibrium state, the results indicate that the Janus MgBrI monolayer is a direct band gap insulator with an energy gap of 3.475 eV, which is smaller than the bandgap of MgI2 and MgBr2 monolayers. The studied optical properties including the complex dielectric function, refractive index, reflectivity, extinction coefficient and absorption coefficient as a function of the photon energy have been investigated. The absorption coefficient shows a strong absorption of the light in the ultraviolet (UV) region. We studied how biaxial strain effects the electronic and optical properties of the Janus MgBrI monolayer. When the strain ranged from −10% to 10%, the Janus MgBrI monolayer showed an insulator characteristic with a direct band gap, which changed to an indirect band gap when the biaxial compressive strain was −10%. In addition, the Janus MgBrI displays an absorption of around 105 cm−1 in the ultra-violet (UV) region. Our results highlight an intriguing new two-dimensional (2D) material that could be used in optoelectronic devices and UV absorbers.

Fundamental study of a femtosecond laser ablation mechanism in gold and the impact of the GHz repetition rate and number of pulses on ablation volume

In this work, we performed an experimental investigation supported by a theoretical analysis of single-shot laser ablation of gold to study the laser-matter interaction for predicting the ablation morphology and optimizing the process parameters. A set of coupled partial differential equations of the two-temperature model with dynamic optical properties and a phase explosion mechanism were used to determine the temporal and spatial evolution of the electron and lattice temperatures. The primary research focus of this work is to use the GHz frequency to investigate the ablation performance because the irradiated material is still far from thermal equilibrium during the laser-matter interaction. In contrast to conventional single-pulse laser ablation, intra-burst frequencies and the number of pulses are important factors in optimizing ablation efficiency and quality for fast material processing. Theoretical investigation revealed that the ablation volume increased due to heat accumulation, but the ablation quality decreased as the intra-burst frequencies decreased from 1000 GHz to 10 GHz. Moreover, the specific ablation volume increases with a higher burst number and lower intra-burst frequency at the expense of ablation quality.