A novel nanocavity-based polymer-on-insulator (POI) electro-optic modulator (EOM) is proposed. It consists of a polymeric photonic-crystal nanobeam cavity (PCNC) with ultra-low index-contrast (n$_{\text{cavity}}$/n$_{bg}$ = 1.17). Based on three-dimensional (3D) finite-difference time-domain (FDTD) method, the PCNC design and optimization are investigated theoretically. A high quality-factor (Q) of 3.4$\,\times\, 10^4$ and small mode-volume of 22.8 ${({\lambda }/n_{SEO}})^{3}$ can be achieved. In order to judge the efficiency of the cavity design for electro-optic (EO) modulation, the optical modes and the electric field distribution are computed using an electromagnetic finite-element solver. Benefiting from the fast and strong EO effect in polymers, the modulator shows an EO modulation efficiency of up to 16 pm/V, which is over an order of magnitude higher than that in lithium niobate (LN) PCNCs. Moreover, the device is only 80 $\mu$m in length, leading to a voltage-length product $V_{\pi }$ × L = 0.05 V$\cdot$cm, which is much smaller than those of Mach-Zehnder modulators. To the best of our knowledge, this is the first on-chip POI-based EOM that features both ultra-compact size and high modulation efficiency. Hence, it is potentially an ideal platform for applications in optical communications, electric-field sensing, and tunable photonic circuits.

中文翻译：

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超低折射率聚合物光子晶体纳米光束电光调制器

提出了一种新型的基于纳米腔的绝缘体上聚合物 (POI) 电光调制器 (EOM)。它由具有超低折射率对比度的聚合物光子晶体纳米束腔 (PCNC) 组成。n$_{\text{cavity}}$/n$_{bg}$= 1.17）。基于三维（3D）有限差分时域（FDTD）方法，从理论上研究PCNC的设计和优化。高品质因数（问) 的 3.4$\,\times\, 10^4$ 和 22.8 的小模式音量 ${({\lambda }/n_{SEO}})^{3}$可以实现。为了判断电光 (EO) 调制腔设计的效率，使用电磁有限元求解器计算光模式和电场分布。得益于聚合物中快速而强大的 EO 效应，调制器的 EO 调制效率高达 16 pm/V，比铌酸锂 (LN) PCNC 高出一个数量级。而且，该设备只有 80 $\mu$长度为 m，导致电压长度乘积 $V_{\pi }$ × L = 0.05 伏$\cdot$cm，远小于 Mach-Zehnder 调制器。据我们所知，这是第一个基于片上 POI 的 EOM，具有超紧凑的尺寸和高调制效率。因此，它可能是光通信、电场传感和可调谐光子电路应用的理想平台。