In this paper, the modulation of the Fano resonance (FR) of dielectric grating has been demonstrated by controlling the crystallization fraction of phase change material film. We analyze the optical characteristics of the grating structure thoroughly by the energy band structure, Q factor, and the electric field distribution of three TE modes. It is verified that the Q factor and the Fano lineshape are related to the thickness of the Ge2Sb2Te5 (GST) layer. In addition, by changing the crystallization fraction of the GST layer, non-volatile modulation of the Q factor can be achieved. We also demonstrate that the crystallization fraction of the GST layer affects the Fano lineshape significantly. By changing the crystallization fraction of the GST layer, the non-volatile modulation of Fano lineshape from asymmetric parameter q = −1 to q = 1 can be achieved. These features make this grating structure an excellent optically reconfigurable device in various fields including lasing spaser and biosensing with improved performance.

中文翻译：

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Ge2Sb2Te5 基光栅结构中 Q 因子和 Fano 线形的调制


本文通过控制相变材料薄膜的结晶分数，论证了介质光栅法诺共振（FR）的调制。我们通过能带结构、Q因子以及三种TE模式的电场分布来深入分析光栅结构的光学特性。验证了Q因子和Fano线形与Ge2Sb2Te5（GST）层的厚度有关。此外，通过改变GST层的结晶分数，可以实现Q因子的非易失性调制。我们还证明 GST 层的结晶分数显着影响 Fano 线形。通过改变GST层的结晶分数，可以实现Fano线形从不对称参数q = -1到q = 1的非易失性调制。这些特性使得该光栅结构成为性能改进的激光SPASER和生物传感等各个领域中优异的光学可重构器件。