A MATLAB package describing discrete dipole approximation (MPDDA) is introduced to calculate the optical properties of arbitrary shaped plasmonic nanoparticles (NPs). The polarizability function, induced dipoles, and dipole interaction matrix are discussed. To calculate the dipole moments, Fast Fourier Transform (FFT) and Biconjugate Gradient (BCG) were used to reduce the computational time and memory. To further accelerate the computational procedure, we used MATLAB functions and toolboxes supported by the graphics processing unit (GPU) and execute them on GPU by supplying a “gpuArray” argument. Using the GPU, the computation cost significantly decreased when compared to the CPU. We also simulated the optical properties of plasmonic NPs, such as extinction, absorption, and scattering efficiencies, electric field enhancement around monomeric and dimeric structures using this package. The accuracy and capabilities of the code have been confirmed by comparing with Mie theory (exact solution) and ADDA code (a DDA package developed in C).

引入了描述离散偶极近似（MPDDA）的MATLAB软件包，以计算任意形状的等离激元纳米粒子（NP）的光学特性。讨论了极化率函数，感应偶极子和偶极子相互作用矩阵。为了计算偶极矩，使用了快速傅里叶变换（FFT）和双共轭梯度（BCG）来减少计算时间和内存。为了进一步加速计算过程，我们使用了图形处理单元（GPU）支持的MATLAB函数和工具箱，并通过提供“ gpuArray”参数在GPU上执行它们。使用GPU，与CPU相比，计算成本大大降低。我们还模拟了等离子体NP的光学特性，例如消光，吸收和散射效率，使用该封装可增强单体和二聚体结构周围的电场。通过与Mie理论（精确解决方案）和ADDA代码（用C语言开发的DDA软件包）进行比较，已经确认了代码的准确性和功能。