硅基狭缝脊形波导的几何尺寸对光场分布的影响

文中采用时域有限差分模拟的方法，研究了狭缝脊形波导中狭缝的宽度、狭缝两侧波导的宽度以及狭缝的深度对狭缝脊形波导光场分布的影响。在狭缝脊型波导中, 随着狭缝宽度的增加, 其归一化光功率先增大后减小；同样，光功率随着狭缝两侧波导的增加也呈现出先增加后减小的现象；随着狭缝刻蚀深度的增加，归一化光功率是逐渐增大的。通过比较狭缝中归一化光功率的值，将其影响量化，进一步找到最合适狭缝脊形波导的几何尺寸。实验结果表明，当狭缝的宽度为40 nm，两侧波导的宽度为220 nm，狭缝刻蚀深度为220 nm时，归一化光功率达到最大值为13.54 %。该仿真结果有助于优化狭缝脊形波导与调制器制造和集成。

Influence of Geometric Dimension of Slot Ridge Waveguide on Light Field Distribution

The influence of the width of the slot in the slot ridge waveguide, the width of the waveguide on both sides of the slot, the thickness of the drapped waveguide in the slot on the distribution of the light field in the slot ridge waveguide were studied by FDTD simulation. In the slot ridge waveguide, the normalized optical power firstly increased and then decreased with the increase of the slot width. Similarly, the optical power also increased first and then decreased with the increase of the waveguides on both sides of the slot; with the increase of slot etching depth, the normalized optical power was gradually increased. And the experimental results showed that the normalized optical power reached the maximum 13.54% when the width of the slot was 40 nm, the width of the two sides of the waveguide was 220 nm, and the silicon of the slot was completely etched. The simulation results were expected to optimize the integration of the slit ridge waveguide with the modulator.