A Ge2Sb2Te5 (GST)-based microring resonator is designed and analyzed for optical switching-based applications. First, the optical properties of GST material having thicknesses of 130 to 230 nm on two commonly used substrates, i.e., silicon (Si) and silicon dioxide (SiO2), are investigated in detail. The phase-change property of GST plays an important role in tuning the resonant wavelength, absorption, and transmission loss in the ring resonator as its crystalline state has a higher refractive index (RI) compared with the amorphous state. Due to the phase-change property of the GST material, the effective RI of the waveguide core changes. A patch of GST is embedded on a ring resonator to optimize the response of light coupled in the ring and straight waveguide, that is tunable between its amorphous phase (a-GST) and crystalline (c-GST) phase. The difference in refractive indices between the two states of a phase-change material (PCM) renders it an optimal choice for the optical active devices used in light modulation and switching applications. The GST is employed as an active material in the proposed structure as it is significantly stable and results in reduced insertion loss (IL) compared with other PCMs. In the proposed design of the ring resonator, the finite-difference time-domain simulation demonstrates high extinction ratios of 16.05 and 20.50 dB at the THROUGH and DROP ports, respectively. Moreover, the low insertion losses (IL) of 0.33 dB at the THROUGH port in crystalline phase and 0.8 dB at the DROP port in amorphous phase, have been observed. The Q-factor of the ring resonator without a GST patch is 5.18×105, whereas with a GST patch, it is 5.13×105 and 1.28×105 in the amorphous and crystalline phases, respectively.

中文翻译：

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用于光开关的 Ge2Sb2Te5 贴片嵌入式环形谐振器

针对基于光开关的应用设计并分析了基于 Ge2Sb2Te5 (GST) 的微环谐振器。首先，详细研究了硅（Si）和二氧化硅（SiO2）两种常用基板上厚度为130至230 nm的GST材料的光学性质。GST 的相变特性在调节环形谐振器中的谐振波长、吸收和传输损耗方面起着重要作用，因为与非晶态相比，其晶态具有更高的折射率 (RI)。由于GST材料的相变特性，波导芯的有效折射率发生变化。GST 贴片嵌入环形谐振器上，以优化环形和直波导中耦合的光响应，该波导可在非晶相 (a-GST) 和结晶相 (c-GST) 之间调谐。相变材料 (PCM) 的两种状态之间的折射率差异使其成为光调制和开关应用中使用的光学有源器件的最佳选择。GST 被用作所提出结构中的活性材料，因为与其他 PCM 相比，它非常稳定，并且可以降低插入损耗 (IL)。在所提出的环形谐振器设计中，有限差分时域仿真表明直通和下降端口分别具有 16.05 和 20.50 dB 的高消光比。此外，在结晶相的 THROUGH 端口处观察到 0.33 dB 的低插入损耗 (IL)，在非晶相的 DROP 端口处观察到 0.8 dB 的低插入损耗 (IL)。没有 GST 贴片的环形谐振器的 Q 因子为 5.18×105，而有 GST 贴片的环形谐振器在非晶相和晶相中的 Q 因子分别为 5.13×105 和 1.28×105。