arXiv subjects

Chengnian Huang

Publications and source records attributed to Chengnian Huang.

4 recordsLinked to original sources

arXiv2025

Parallel overlapping-domain decomposition FDFD for large-scale complex nanostructures modeling

The increasing complexity and scale of photonic and electromagnetic devices demand efficient and accurate numerical solvers. In this work, we develop a parallel overlapping domain decomposition method (DDM) based on the finite-difference frequency-domain (FDFD) formulation to model the electromagnetic response of large-scale complex nanostructures. The global computational domain is partitioned into multiple overlapping subdomains terminated with perfectly matched layers (PMLs), enabling seamless source transfer between adjacent subdomains. A multi-frontal preconditioner is employed to accelerate the iterative solution process, while an OpenMP-based parallel implementation ensures high scalability. Several numerical examples are provided to validate the efficiency and accuracy of the proposed algorithm. The results demonstrate excellent agreement with analytical and commercial COMSOL solutions. Notably, the method achieves up to an order of magnitude reduction in computation time, highlighting its potential as a powerful tool for large-scale photonic and electromagnetic modeling.

physics.optics↗

arXiv2025

Modeling of Far-Field Quantum Coherence by Dielectric Bodies Based on the Volume Integral Equation Method

The Hong-Ou-Mandel (HOM) effect is a hallmark of nonclassical two-photon interference. This paper develops a unified theory-numerics framework to compute angle-resolved far-field two-photon correlations from arbitrary lossless dielectric scatterers. We describe the input-output relation using a multi-channel scattering formulation that maps two populated incident channels to two selected far-field detection modes, yielding a compact two-channel transfer relation for second-order correlation function and time-domain coincidence counts. The required transfer coefficients are extracted from classical far-field complex amplitudes computed by an fast Fourier transform-accelerated volume integral equation solver, avoiding perfectly matched layers and near-to-far-field post-processing. The method is validated against analytical results for dielectric spheres and demonstrated on a polarization-converting Pancharatnam-Berry-phase metasurface, revealing strong angular dependence of quantum interference and its direct impact on HOM-dip visibility. The framework provides an efficient and physically transparent tool for structure-dependent quantum-correlation analysis, with potential applications in scatterers-enabled quantum state engineering and quantum inverse design.

quant-ph↗

arXiv2025

Extraction of power transmission parameters from PT-symmetric waveguides

The PT-symmetric waveguides have been frequently discussed in the photonics community due to their extraordinary properties. Especially, the study of power transmission is significant for switching applications. The aim of this study is to extract the mode power transmission parameters based on the coupled mode equations and analyze the power properties of the PT-symmetric system. The equations relying on the coupled mode theory are constructed according to the two different orthogonality relations between the original and adjoint system. The results matching well with the finite difference simulations demonstrate the validity of our method, while the conventional coupled mode theory fails. The power properties in the PT-symmetric and PT-broken phases are also observed. Furthermore, a new integration is implemented from which the conserved quantity is defined and extracted, which reflects the Hamiltonian invariant of the system. Our method fully incorporates the properties of complex modes and allows the study of the power transmission properties based on the orthogonality relations, which is also applicable to other types of non-Hermitian optical systems. This work provides a new perspective for the power analysis of PT-symmetric waveguides and is helpful to design the switching devices.

physics.optics↗

arXiv2025

A Parallel Block Preconditioner-Based VIE-FFT Algorithm for Modeling the Electromagnetic Response From Nanostructures

The superior ability of nanostructures to manipulate light has propelled extensive applications in nano-electromagnetic components and devices. Computational electromagnetics plays a critical role in characterizing and optimizing the nanostructures. In this work, a parallel block preconditioner based volume integral equation (VIE)-fast Fourier transform (FFT) algorithm is proposed to model the electromagnetic response from representative nanostructures. The VIE using uniform Cartesian grids is first built, and then the entire volumetric domain is partitioned into geometric subdomains based on the regularity and topology of the nanostructure. The block diagonal matrix is thus established, whose inverse matrix serves as a preconditioner for the original matrix equation. The resulting linear system is solved by the bi-conjugate gradient stabilized (BiCGSTAB) method with different residual error tolerances in the inner and outer iteration processes; and the FFT algorithm is used to accelerate the matrix-vector product (MVM) operations throughout. Furthermore, because of the independence between the inner processes of solving block matrix equations, the OpenMP framework is empolyed to execute the parallel operations. Numerical experiments indicate that the proposed method is effective and reduces both the iteration number and the computational time significantly for the representative nano-electromagnetic problems like the dielectric focusing metasurfaces and the plasmonic solar cells.

physics.comp-ph↗