本研究以單一點波源模型建構電磁波穿過完美導體之次波長聚焦結構後其磁場空間分佈為主要目的。其中，此完美導體結構為一次波長狹縫與單一金屬凹槽構成。透過能量流守恆，藉由小系統的模擬得到穿透狹縫後的總能量流，得出單一點波源模型之振幅，最後成功地建立起符合電磁波數值模擬的磁場分佈。此外我們藉由理論計算分析金屬凹槽內部電磁波之相位與能量關係，我們發現狹縫與凹槽間距不影響由凹槽輻射至遠場的能量比例，且其能量比只與凹槽深度所造成之電磁波相位差有關。我們以相較以往簡單明確的方式，建構出能夠減少大量運算時間支點波源模型；透過此方法，我們相信能應用於更多有關本結構的光學特性，以增加我們對次波長動力學與相關方面的瞭解。

We constructed the spatial distribution of the magnetic field caused by an electromagnetic wave going through a sub-wavelength focusing structure in a perfect electrical conductor (PEC) film with a single point source model. Through the whole process, we hope to understand more about sub-wavelength wave mechanics.
The total energy flow through the slit is obtained from a small system simulation, and the amplitude of the single point source model is obtained by the conservation of energy flow. In addition, by theoretically analyzing the relationship between the phase and energy of the electromagnetic wave in the metal groove, we find that the distance between the slit and the groove does not affect the ratio of the energy radiated from the groove to the far field. The energy ratio is only caused by the groove depth because of the phase difference of the electromagnetic wave. We have built a fulcrum wave source model that can reduce a large number of computations over simple and straightforward approaches; by this method, we believe it can be applied to more of the optical properties of the structure to increase our understanding of subwavelength dynamics.

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