Jafari Zeinab, Zarifkar Abbas
Appl Opt. 2016 Nov 10;55(32):9084-9090. doi: 10.1364/AO.55.009084.
A subwavelength structure deposited on top of a silicon strip is utilized as a novel tool for dispersion engineering. The equivalent refractive index of the subwavelength structure can be tailored through adjusting its period and duty cycle. As finding suitable materials with both appropriate refractive index and fabrication compatibility is one of the main difficulties in dispersion engineering, the possibility of refractive index engineering is the most significant advantage of the proposed waveguide. It can be beneficial for controlling the properties of the fundamental quasi-TM mode and consequently its dispersion characteristics without any concern about material compatibility. Utilizing this waveguide geometry, a wide and flattened low-dispersion bandwidth can be achieved. Moreover, high anomalous and normal dispersion is realizable without any degradation in dispersion flatness over bandwidth. Therefore, the proposed waveguide structure is promising for dispersion tailoring in both linear and nonlinear applications.
沉积在硅条顶部的亚波长结构被用作色散工程的一种新型工具。亚波长结构的等效折射率可通过调整其周期和占空比来定制。由于找到具有合适折射率和制造兼容性的合适材料是色散工程中的主要困难之一，折射率工程的可能性是所提出的波导的最显著优势。它有利于控制基模准横磁（quasi-TM）模式的特性，从而控制其色散特性，而无需担心材料兼容性。利用这种波导结构，可以实现宽且平坦的低色散带宽。此外，在带宽上的色散平坦度没有任何下降的情况下，可以实现高反常色散和正常色散。因此，所提出的波导结构在线性和非线性应用中的色散定制方面具有前景。
