在FDTD中提取某个点场强值并绘制出场强随波长变化的脚本

假设你已经在FDTD中完成了模拟，使用Python脚本提取某个点场强值并绘制出场强随波长变化的步骤如下：

1. 导入必要的库和模块

import meep as mp
import numpy as np
import matplotlib.pyplot as plt

2. 定义模拟的相关参数

resolution = 100  # 空间分辨率
cell_size = mp.Vector3(10, 10, 0)  # 模拟区域大小
wavelength_min = 0.4  # 波长范围最小值
wavelength_max = 1.0  # 波长范围最大值
num_points = 100  # 绘图点数

3. 创建模拟空间并添加结构

# 创建模拟空间
sim = mp.Simulation(cell_size=cell_size, resolution=resolution)

# 添加结构
geometry = [mp.Block(mp.Vector3(5, 5, mp.inf),
                     center=mp.Vector3(),
                     material=mp.Medium(epsilon=12))]
sim.geometry = geometry

4. 添加源和探测器

# 添加正弦波源
sources = [mp.Source(mp.ContinuousSource(wavelength=0.8),
                     component=mp.Ez,
                     center=mp.Vector3(0, 0, 0),
                     size=mp.Vector3(0, 0, 0))]

# 添加探测器
frequency_centers = np.linspace(wavelength_min, wavelength_max, num_points)
spectra = []
for center in frequency_centers:
    d = sim.add_flux(center, 0, 1, mp.FluxRegion(center=mp.Vector3(), size=mp.Vector3(1, 1, 0)))
    spectra.append(mp.SpectrumCenter(center, d))

# 运行模拟
sim.run(mp.at_beginning(mp.output_epsilon),
        mp.to_appended("ez", mp.at_every(0.6, mp.output_efield_z)),
        until=200)

5. 提取场强值并绘制图像

# 提取场强值
field_data = sim.get_array(center=mp.Vector3(), size=mp.Vector3(1, 1, 0), component=mp.Ez)
field_data_abs = np.abs(field_data)

# 绘制图像
plt.plot(frequency_centers, field_data_abs)
plt.xlabel('Wavelength (μm)')
plt.ylabel('|Ez|')
plt.show()

这个脚本将绘制出场强随波长变化的图像。你可以根据需要修改模拟参数和绘图参数。