Finite-difference Time-domain Approach Research Articles

Sensing of lactose by graphitic carbon nitride/magnetic chitosan composites with surface plasmon resonance method

A simple technique was used to create a composite material made of graphitic carbon nitride supported on magnetic chitosan (g-C3N4/MNP/CS). This substance was employed in the structure of a surface plasmon resonance (SPR) lactose biosensor as a modifier for a thin layer of gold and as a support for the covalent stabilization of cellobiose dehydrogenase. The Finite-Difference Time-Domain (FDTD) approach was used to mimic the sensor's evanescent field in order to examine the SPR behavior. Additionally XRD and SEM techniques were used to examine the shape of MNPs/CS/g-C3N4 and the intended sensor's SPR behavior. It can be used in the food industry, with a detection limit of 5 μM and a linear range of 0.01–100 mM‏ The biosensor is extremely sensitive, demonstrating its accuracy in lactose detection.

Graphene-based polarization insensitive structure of ultra-wideband terahertz wave absorber

Graphene, a new smart material, has gained a lot of attention recently because of its tunable band structure and strong light-matter interaction. In comparison with typical absorbers, graphene absorbers have emerged as a highly attractive substitute for various types of applications. To broaden the absorption bandwidth, a two-dimensional graphene-based ultra-wideband and polarization-insensitive novel terahertz (THz) absorber with absorption over 95 % from 3.0 THz to 8.5 THz is proposed, with peak absorption of 99.9 % at 6.6 THz and average absorption of 98.4 % for the 5.5 THz bandwidth. The surface plasmon increased by the gold-graphene structure, the Mei resonance, and the interference cancellation between metasurfaces collectively contribute to the ultra-wideband absorption. To obtain nearly perfect broadband terahertz absorption, a single layer of graphene is used. The finite difference time domain (FDTD) approach is used for absorber analysis. In addition, the absorber is insensitive to the polarization angles and incidence angles of incident electromagnetic waves. The proposed graphene-based absorber dominates previously reported wideband THz absorbers in terms of over 95 % bandwidth, absorption peak value, and overall volume. This research will present a novel idea for the design of an ultra-wideband absorber, which can be considered a suitable candidate for different potential applications in terahertz imaging, sensors, photodetectors, and modulators.

Domain Decomposition Hybrid Implicit–Explicit Algorithm with Higher-Order Perfectly Matched Layer Formulation for Electrical Performance Evaluation under Low-Pressure Discharge Phenomenon

Low-pressure discharge events have a major impact on a satellite’s electrical performance. Most notably, a number of serious issues arise from the inability to directly modify satellite systems that operate in orbit. Accurate analysis of electrical performance is crucial for mitigating the issues arising from the low-pressure discharge phenomenon. Complex structures, such as intricate features and curved structures, are frequently used in satellite systems’ enormous microwave components. In this case, the finite-difference time-domain (FDTD) approach proposes the hybrid implicit–explicit (HIE) algorithm with a domain decomposition method to effectively simulate complex structures under the low-pressure discharge phenomenon. The bilinear transform method is adjusted in accordance with the implicit equations for the anisotropic magnetized plasma environment caused by the discharge. To end unbounded lattices, a higher-order perfectly matched layer is used at the boundary. An example of a microwave connector structure is used to show how well the algorithm performs electrically. According to the findings, the suggested algorithm behaves in a way that is consistent with both the traditional algorithm and the experiments. Furthermore, the phenomenon of low-pressure discharge has a notable impact on the electrical performance of microwave components.

Modeling Time-Evolving Electrical Conductivity in Air Ionization Plasma under DC Voltage: A Finite-Difference Time-Domain Approach for Needle-Plate Setup Based on Laboratory Experiments

In this paper, we develop a finite-difference time-domain (FDTD) model in which the time-evolving electrical conductivity of the air ionization plasma in DC voltage needed-plate setup is represented. Maxwell’s equations are solved using the FDTD method, and the associated currents and discharge fields are computed over time and in three-dimensional space. The proposed model for the electrical conductivity is dependent on time, the applied DC voltage, and the gap length. The necessary data for developing the proposed model is obtained experimentally using a standard discharge needle, with its spherical tip measuring approximately 40 μm in diameter. Once high voltage is applied, a steady state is achieved. The electrical conductivity σ(t) and its associated parameters are then calculated using nonlinear equations proposed to reproduce the experimentally obtained plasma behavior in the full-wave FDTD model. Voltage ranges from 4 kV to 9 kV, and gap distances are between 4 mm and 8 mm.

Analysis of Moving Bodies with a Direct Finite Difference Time Domain Method

This paper proposes an original and thorough analysis of the behavior of electromagnetic waves in the presence of moving bodies by using the finite difference time domain (FDTD) method. Movements are implemented by changing positions of the objects at each time step, through the classical FDTD time loop. This technique is suitable for non-relativistic speeds, thus for most encountered problems in antennas and propagation domain. The numerical aspects that need to be considered are studied. Then, different bodies in motion are examined: plane wave source with matching resistors, observation point, inclined partially reflecting surface (PRS), line source, and metallic cylinder illuminated by a plane wave. The results are compared with those of special relativity which are considered as the references. Some aspects of special relativity are present in the direct FDTD approach, such as the independence of the velocity of electromagnetic wave propagation with the speed of the source and Lorentz local time (with a different physical interpretation). It is shown that the amplitude of the electric field for a moving plane wave source does not increase with the speed of motion, if the impedance of the source is small. Moreover, for a moving scattering metallic wire, one can observe a phenomenon similar to shock waves.

Numerical investigation into impact of halide perovskite material on the optical performance of prism-loaded hybrid surface plasmon resonance biosensor: A strategy to increase sensitivity

The technology of surface plasmon resonance (SPR) is widely recognized and valued for its ability to rapidly and sensitively investigate biomolecular interactivities in real-time. Herein, we numerically investigate the collective influence of metal/ transition metal dichalcogenide (TMDC)/halide perovskite (HP)/2D carbon (C) and phosphorus (P) allotropes on the functionality of an SPR biosensor deploying Kretschmann configuration. The incident light wavelength is held constant at 633 nm, and radiative properties of the hybrid structure are determined using the attenuated total reflection and transfer matrix techniques. Crucial performance metrics such as quality factor (QF), figure of merit (FoM), sensitivity, and detection accuracy are calculated. The comparison is conducted and evaluated against the current literature using performance outcomes in terms of several prisms such as BK7, BAK1, BAF10, SF5, SF10, SF11, 2S2G, CaF2, and CsF, several TMDCs such as WS2, MoS2, WSe2, MoSe2, and PtSe2, several HPs such as CsPbI3, KSnI3, CsSnI3, and FASnI3, and 2D C/P allotropes such as Graphene, MXene, Black phosphorene (BP), and Blue phosphorene (BlueP) in order to search optimum parameters, and then we implement the best one in each layer of this biosensor design. It is noticed that the SPR heterostructure based on BAK1 prism, plasmonic metal Ag, tungsten disulfide (WS2) TMDC, formamidinium tin iodide (FASnI3) HP and 2D BP exhibits outstanding performance with regard to sensor performance characteristics. The observed FoM and sensitivity are 48.2/RIU and 402°/RIU, respectively. The investigation of the electric field distribution within this biosensor along the normal to the interface is also conducted using the finite difference time domain (FDTD) approach to demonstrate the unique contribution of FASnI3. The findings presented in this study are anticipated to play a key role in the improvement of plasmonic resonance-based biosensing domains like DNA hybridization or formalin detection by employing halide perovskite as an additional layer in SPR biosensors.

A Refined Combined Grid Model for Characterizing Concealed Microcracks with Various Geometric Shapes Based on Radar Signal Processing

The concealed microcracks in shield tunnel lining present the characteristics of being of small size, unknown shape, and are difficult to detect. Based on the finite-difference time domain (FDTD) approach, this study proposed a new construction method of a refined grid accommodating and combining the variable shapes of microcracks, and capable of designing cross type, mesh type, and wave type microcrack models. The proposed new method also configured steel bars in the models to simulate actual engineering conditions, and characteristic response images of the models under different working conditions were obtained using ground penetrating radar (GPR) technology, which were then compared and analyzed to identify the imaging characteristics and differences of microcracks with variable geometric shapes. The waveform, amplitude, and time span of the characteristic single channel signal were furthermore studied. The results showed that the new method could successfully simulate the GPR characteristic response images of 0.5[Formula: see text]mm microcracks of diverse geometric shapes. When the microcracks were wavy, their real shape could only be determined after signal pre-processing; the density and quantity of steel bars directly affected the appearance of microcrack characteristic signals; the greater the density and quantity of steel bars, the greater the interference on the waveform, amplitude, and time-frequency range of electromagnetic wave signals; a special correlation existed between the maximum mean root square value of the amplitude and the single channel signal of the cracks. Moreover, the finding that the extension in time and distance in the GPR time distance profile intersected with the cracks was deemed potentially to provide fresh insights into identifying the characteristic points of the cracks in the GPR images. The new method proposed in this study successfully obtained the GPR numerical simulation images and characteristic signals of microcracks with variable geometric shapes. Through the processing and analysis of the characteristic response signals of microcracks, the conclusions obtained were considered to provide an interpretation basis for the detection of microcracks in practical engineering.

Design and simulate the demultiplexer using photonic crystal ring resonator for DWDM system

In this study, a new four channel de-multiplexer with a ring resonator design is proposed. The bus waveguide and drop waveguide that make up the Ring Resonator are ring-shaped. In the proposed four channel demultiplexer design, one bus waveguide and four drop waveguides were built using a photonic crystal ring resonator. To improve output efficiency, the proposed demultiplexer was built with distinct inner radius values for each channel. With the resonance wavelengths for each channel in the range of 1552.4 nm, 1553.2 nm, 1554.1 nm, and 1555.4 nm, the suggested demultiplexer average quality factor was 7870.90, and its average transmission efficiency was 98.67%. The demultiplexer was created with a 0.8 nm narrow channel spacing with a − 15 dB to − 25 dB crosstalk range. The proposed ring resonator structure is made of silicon, which has a refractive index of 3.47, a center wavelength ranges of 1550 nm, and a lattice constant that varies with the radius range of 540 nm. To examine the performance, one can simulate the suggested demultiplexer structure using the FDTD (Finite-Difference Time-Domain) approach. The proposed work 198.7 µm2 footprint is appropriate for DWDM applications.

Initial Finite-Difference Time-Domain (FDTD) Modeling of Graphene Based on Intra-band Surface Conductivity

Graphene is a single two-dimensional layer of carbon atoms arranged in a hexagonal lattice, possesses interesting optical properties, and has potential for applications in optical devices. Graphene exhibits tunable surface conductivity, which arises from its electronic band structure. Graphene surface conductivity is determined by its chemical potential, which can be controlled by bias voltage and/or chemical doping. The tunability of surface conductivity allowed to tailored optical properties of graphene, making it a controllable material for optoelectronic applications. Graphene surface conductivity is applied to update the field values at each time step in the Finite-Difference Time-Domain (FDTD) method, enabling us to visualize electromagnetic (EM) wave propagation in graphene. The current article serves as a starting point for developing the FDTD approach to simulate EM wave interactions with graphene, particularly at low frequencies. In this study, we use the Kubo formula for low EM wave frequency (10-105 GHz) at ambient temperature to calculate the intra-band surface conductivity of graphene. The outcome shows that the imaginer’s intra-band surface conductivity value is relatively considerable compared to the actual value at frequencies between 102 and 104. Moreover, the chemical potential exhibits a positive linear relationship with the imaginer intra-band surface conductivity and the intra-band conductivity falls to zero as the frequency rises to NIR.

Aluminum Nano Stars with Localized Surface Plasmon Resonance and Field Enhancement

Aim: The Finite Difference Time Domain approach has been used to assess the localised surface plasmon resonance and field enhancement for Al nanostars. The structure's potential as a refractive index sensor has been demonstrated. Background: Research on plasmonics has been possible in a variety of domains, including sensors, SERS, solar cells, and others, due to a tenability in the plasmon wavelength caused by a simple change in shape, size, or external environment. The growth of plasmonics has been greatly aided by the creation of novel ways for creating metallic nanostructures and a large deal of work on the creation of numerical algorithms to cope with arbitrarily shaped metallic nanostructures. The LSPR and field enhancement of an Al nano-star were the main topics of this paper. A larger RIS factor is obtained after adjusting the refractive index sensitivity parameter, making it appropriate for refractive index-based sensor nanostructures. Objective: This study's primary goal is to provide a comparative analysis of the refractive index sensitivity factor for Al nanostars dependent on their size and number of arms. Methods: Al nano star's LSPR and field enhancement have been assessed using the Finite Difference Time Domain (FDTD). Results: By altering the size and number of arms of the nano star, the tenability of the plasmonic peak has been assessed, and it has been found that the peak is sensitive to the ambient dielectric constant. A study has been done on the refractive index sensitivity parameter. A higher sensitivity of about 370 nm/RIU, which is significantly higher than that of other metallic Nanostar (NS), is seen after adjusting the size and number of arms. A wide range of applications is covered by the Al NS field enhancement pattern, which exhibits stronger enhancement with no aggregation at the plasmon peak. Conclusion: For LSPR sensing applications, the impact of modifying the environmental dielectric constant is examined. By changing the size and quantity of the Al NS's arms, we were able to compare the refractive index sensitivity parameter. The bigger size NS exhibits more peaks due to the contribution of the multipole; however, after tuning a number of parameters, better sensitivity in comparison to Au and Ag nanostar has been attained. Al NS can therefore be a promising sensing material for refractive index sensing employing LSPR properties.

Investigations of all-optical gates based on linear photonic crystals using the PSK technique and beam interference effect

ABSTRACT In this paper, all optical OR, AND, NOR and NAND gates based on linear photonic crystals (LPhCs) have been numerically designed and simulated by the plane wave expansion (PWE) and finite difference time domain (FDTD) methods. The LPhC fundamental structure with cross-section of 114 is used for designing the proposed all optical gates (AOGATEs), which is composed of 15 × 23 cubic matrix of dielectric silicon rods in air substrate. The mechanism of the proposed AOGATEs is performed based on phase shift keying (PSK) technique and beam interference effect. Simulation results by FDTD approach illustrate the minimum contrast ratio of 8.88 and 10.31 dB for all optical AND/NOR and OR/NAND logic gates, respectively. Also, the minimum bit rate is obtained as 3.34 Tb/s for AND/NOR and 5 Tb/s for OR/NAND logic gates.

Highly tunable and ultrasensitive hybrid plasmonic platform for multi-spectral sensing: Non-invasive diabetes surveillance and global warming directives

The development of tunable and extremely sensitive devices, as well as the emergence of metamaterials, has tremendously aided the evolution of plasmonic sensing technologies. However, the natural property of metamaterials severely restricts the scalability and application potential of mono-functional sensor systems. To address this shortcoming, we have investigated an ultranarrow five-band plasmonic sensor with structural tunability and high sensing behaviors in compatibility with multi-purpose application scenarios, using the finite-difference time-domain approach rigorously. Meanwhile, we theoretically formulated a hybridization model for the mutual induction of Fabry–Pérot resonances and localized surface plasmon polariton resonance, providing a theoretical basis for the utilization and conception of the highly-sensitive tunable plasmonic sensor. Most notably, we discovered and interpreted far-field phase extinction inducing separation of polarization resonance peaks in physical mechanisms. The tunability of its mutual inductance effect at the intersection distances from two-intersecting silver nanogroove was adequately exploited to further validate and effectively attain five ultra-narrow absorptivities of 96.70%, 93.93%, 99.73%, 100.00%, and 89.72% by top-level optimization. In addition, the redundant proximity between nearby peaks is compensated, extending the operating band and enhancing the practicability in multi-purpose scenarios. As a reliable source for future optical sensing, it performs well in the visible to near-infrared region, enabling detection response to non-invasive diabetes mellitus, global climate warming, and unrestricted temperature and pressure measurement. Meanwhile, minimum FWHM = 4.806 nm and maximum FOM = 115.13 RIU−1 are obtained at 293.15 K, with an associated highest sensitivity of 557.93 nm/RIU. Moreover, the fabrication technologies development of electron beam lithography and focused ion beam etching technologies enables large-scale mass production at low cost and long-term stability.

An Efficient FDTD Method Based on Subgridding Technique and One-Step Leapfrog ADI-FDTD

In this letter, a 3-D subgridding finite-difference time-domain (FDTD) approach is proposed. The calculation domain is divided into regions with dense meshes and regions with coarse meshes. By applying the proposed subgridding technique to dense grid regions, memory and computation resources can be significantly reduced. Furthermore, the Courant–Friedrich–Levy (CFL) limitation of dense mesh regions is broken by the one-step leapfrog alternately direction-implicit (ADI)-FDTD. Coarse and dense regions can adopt a uniform time step, which is limited only by the standard FDTD CFL condition for coarse meshes. In comparison with the standard FDTD approach and the subgridding FDTD approach, numerical results demonstrate the efficiency and accuracy of the proposed method.

A performance comparison of heterostructure surface plasmon resonance biosensor for the diagnosis of novel coronavirus SARS-CoV-2.

This paper presents a performance comparison of heterostructure surface plasmon resonance (SPR) biosensors for the application of Novel Coronavirus SARS-CoV-2 diagnosis. The comparison is performed and compared with the existing literature based on the performance parameters in terms of several prisms such as BaF2, BK7, CaF2, CsF, SF6, and SiO2, several adhesion layers such as TiO2, Chromium, plasmonic metals such as Ag, Au, and two-dimensional (2D) transition metal dichalcogenides materials such as BP, Graphene, PtSe2 MoS2, MoSe2, WS2, WSe2. To study the performance of the heterostructure SPR sensor, the transfer matrix method is applied, and to analyses, the electric field intensity near the graphene-sensing layer contact, the finite-difference time-domain approach is utilized. Numerical results show that the heterostructure comprised of CaF2/TiO2/Ag/BP/Graphene/Sensing-layer has the best sensitivity and detection accuracy. The proposed sensor has an angle shift sensitivity of 390°/refractive index unit (RIU). Furthermore, the sensor achieved a detection accuracy of 0.464, a quality factor of 92.86/RIU, a figure of merit of 87.95, and a combined sensitive factor of 85.28. Furthermore, varied concentrations (0-1000nM) of biomolecule binding interactions between ligands and analytes have been observed for the prospects of diagnosis of the SARS-CoV-2 virus. Results demonstrate that the proposed sensor is well suited for real-time and label-free detection particularly SARS-CoV-2 virus detection.

Comparison of thermal effects induced by transcranial focused ultrasound and transcranial pulse stimulation

Abstract The objective of the study was to investigate thermal effects induced through two low-intensity focused ultrasound (LIFU)–based brain stimulation techniques—transcranial focused ultrasound stimulation (tFUS) and transcranial pulse stimulation (TPS). Long trains of acoustic pulses are delivered using tFUS, whereas, the newly introduced TPS delivers ultrashort (∼3 μs) pulses repeated at 4 Hz. It is presumed that TPS by virtue of delivering ultrashort ultrasound pulses reduces the risk for brain heating, but this has not been quantified in the literature. While overall temperature increase depends on the exact combination of stimulation parameters, simulations for tFUS have predicted ∼3°C and ∼<0.2 °C rises in a monkey skull and brain respectively. To our knowledge, the maximum rise ever reported is ∼3°C in rat brain but via a combination of longer duration and higher Ispta than typically used in tFUS. Following our previous work developing an image-derived model for TPS, we extended the models to assess transient heating in TPS as compared to tFUS. A finite difference time domain approach was used to solve the Westervelt-Lighthill equation for the pressure distribution in the head. Average intensity was calculated from the pressure distribution, which was then coupled to Pennes bioheat equation as a heat source. Initial results using certain assumptions indicate brain temperature rises in TPS to be <0.01°C. This indicates temperature rise at least an order of magnitude lower than some common tFUS parameters. While the absolute heating induced by either modality can be modulated by adjusting Ispta (through transducer intensity, duration, or duty cycle), typical tFUS and TPS protocols produce inherently different proportions of temperature versus pressure changes. In addition to risk, knowing the relative differences in temperature versus pressure generated could lend to a deeper understanding of the thermal versus mechanical mechanisms underlying the two techniques. Research Category and Technology and Methods Translational Research: 19. Modeling and computational methods Keywords: Ultrasound, tFUS, TPS, Thermal

The impact of plasmonic electrodes on the photocarrier extraction of inverted organic bulk heterojunction solar cells

Nano-patterning the semiconducting photoactive layer/back electrode interface of organic photovoltaic devices is a widely accepted approach to enhance the power conversion efficiency through the exploitation of numerous photonic and plasmonic effects. Yet, nano-patterning the semiconductor/metal interface leads to intertwined effects that impact the optical as well as the electrical characteristic of solar cells. In this work we aim to disentangle the optical and electrical effects of a nano-structured semiconductor/metal interface on the device performance. For this, we use an inverted bulk heterojunction P3HT:PCBM solar cell structure, where the nano-patterned photoactive layer/back electrode interface is realized by patterning the active layer with sinusoidal grating profiles bearing a periodicity of 300 nm or 400 nm through imprint lithography while varying the photoactive layer thickness (LPAL) between 90 and 400 nm. The optical and electrical device characteristics of nano-patterned solar cells are compared to the characteristics of control devices, featuring a planar photoactive layer/back electrode interface. We find that patterned solar cells show for an enhanced photocurrent generation for a LPAL above 284 nm, which is not observed when using thinner active layer thicknesses. Simulating the optical characteristic of planar and patterned devices through a finite-difference time-domain approach proves for an increased light absorption in presence of a patterned electrode interface, originating from the excitation of propagating surface plasmon and dielectric waveguide modes. Evaluation of the external quantum efficiency characteristic and the voltage dependent charge extraction characteristics of fabricated planar and patterned solar cells reveals, however, that the increased photocurrents of patterned devices do not stem from an optical enhancement but from an improved charge carrier extraction efficiency in the space charge limited extraction regime. Presented findings clearly demonstrate that the improved charge extraction efficiency of patterned solar cells is linked to the periodic surface corrugation of the (back) electrode interface.

Propagation of an Ultrawideband Electromagnetic Pulse Along a Plasma-Filled Coaxial Line

The propagation of an ultrawideband (UWB) electromagnetic pulse along a coaxial line filled with a cold isotropic plasma is considered. The pulse shape evolution is studied both in the frequency domain through the Fourier transform analysis and in the time domain using either the high-frequency approximation or the finite-difference time-domain (FDTD) approach. The emphasis is placed on the behavior of the pulse shape for various values of the plasma density in the coaxial line. It is shown that transmission of a nanosecond TEM pulse in a plasma-filled coaxial line can serve for revealing the basic features of changes in the shape of such signals during their propagation in an unbounded plasma medium.

Design and implementation of all optical OR and NOR gates based on PhC structure and nonlinear Kerr effect

Abstract In the present work, nonlinear ring resonator based on two-dimensional hexagonal photonic crystal structure is designed for all optical OR and NOR gates in the wavelength range of 1355–2053 nm. The OR and NOR gates are made up of four optical waveguides which are critically coupled to a nonlinear ring resonator. The electric field distribution and photonic band gap characteristic of the proposed gates are solved by Maxwell equations using finite difference time domain and plane wave expansion methods, respectively. Simulation results by finite difference time domain approach show the minimum contrast ratio of 12.04 and 11.81 dB for OR and NOR logic gates, respectively. Also, the minimum delay time is obtained 1 ps for OR and 1.5 ps for NOR logic gates.

Multilayered Ge/W thin-film for high-efficient passive heat dissipation

Effective surface passive heat dissipation is critical for energy power systems in optical devices and electronics. Here, we theoretically and experimentally investigate a multilayer Ge/W structure to enhance radiative heat dissipation. The proposed structure is optimized by employing a hybrid method of the transfer matrix method (TMM) and the genetic algorithm (GA). The optimized structure is fabricated using the magnetron sputtering technique and has an average emissivity (∼82.3 %) at thermal radiative wavelengths ranging from 3 to 16 μm. The finite difference time domain (FDTD) approach and phase analysis demonstrate that the superimposed multiple Fabry-Perot resonances and the antireflection properties result in strong infrared emissivity in the thermal wavelength range. In indoor high-temperature object-cooling experiments, an object coated with this heat dissipation material outperforms a pure W film material in terms of cooling performance, with a maximum temperature difference of 34.3 °C. The planar film structure dramatically reduces the difficulties and cost of fabrication, thus showing excellent development potential in the field of passive heat dissipation.

Efficacious GPR Implementations of Z-Transform-Based Hybrid LOD-FDTD with Subgridding Scheme: Theoretical Formalism and Numerical Study

Ground penetrating radar (GPR) forward modeling is one of the core geophysical research topics and also the primary task of simulating ground penetrating radar system. It is a process of simulating the propagation laws and characteristics of electromagnetic waves in simulated space when the distribution of internal parameters in the exploration region is known. And the finite-difference-time-domain (FDTD) method has the characteristics of simulating the space-time transient evolution of electromagnetic wave, whose numerical method is simple and easy to program, so it has become one of the most extensively utilized methods in GPR forward modeling. It is generally known that the conventional FDTD approach requires finer uniform Yee cell all the time to produce satisfactory accuracies from numerical simulations of the GPR. However, the smaller temporal incremental has to be adopted due to the lower spatial incremental, which would dramatically weaken the advantage of the FDTD method. To solve this issue, the subgridding-technique-based hybrid local-one-dimensional FDTD (LOD-FDTD) is applied in this work to modeling the classical GPR scenarios. In this method, the unconditional-stable LOD-FDTD is employed in the fine-grid domain, while the traditional FDTD is used in the coarse-grid domain, which could avoid the oversampling problem in the local domain if the uniform fine-grid scheme is adopted. Meanwhile due to the unconditional stability of the LOD-FDTD, the larger time step, derived from the coarse grid which satisfies the Courant-Friedrichs-Lewy (CFL) stability condition, could be utilized in the whole domain so that the long-time interpolation process could be circumvented. Additionally, the proposed approach could be arbitrarily adjusted by means of different ratio of both coarse- and fine-grid, and hence it holds much higher generality. As compared with the auxiliary differential equation (ADE) technique, the Z-transform method is integrated into FDTD methods for modeling multi-pole Debye-based dispersive media in this method, resulting in more direct numerical implementations and fewer computing steps. Finally, three different classical GPR problems are carried out to validate accuracies and efficiencies of the proposed method.