Butt Muhammad A, Piramidowicz Ryszard
Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
Micromachines (Basel). 2024 Nov 28;15(12):1434. doi: 10.3390/mi15121434.
In this work, we propose a novel suspended slot membrane waveguide (SSMW) utilizing a germanium-on-silicon-on-insulator (Ge-on-SOI) platform for carbon dioxide (CO) gas-sensing applications. The design and analysis focus on the absorption line of CO in the mid-infrared region, specifically at a wavelength of 4.23 µm. The waveguide geometry has been precisely optimized to achieve a high evanescent field ratio (EFR) and minimize waveguide propagation losses. These optimizations significantly enhance the sensitivity of the waveguide, making it highly effective for evanescent field absorption-based gas sensing. Our optimized waveguide geometry demonstrates a notable EFR of 0.86, with a low propagation loss of just 1.07 dB/cm, and achieves a sensitivity as high as ~1.12 × 10 ppm for SSMW lengths as short as 0.9 cm.
在这项工作中，我们提出了一种新型的悬浮狭缝膜波导（SSMW），它利用绝缘体上硅基锗（Ge-on-SOI）平台用于二氧化碳（CO）气体传感应用。设计和分析聚焦于中红外区域CO的吸收线，具体为波长4.23 µm处。波导几何结构已被精确优化，以实现高倏逝场比率（EFR）并最小化波导传播损耗。这些优化显著提高了波导的灵敏度，使其对于基于倏逝场吸收的气体传感非常有效。我们优化后的波导几何结构展现出显著的0.86的EFR，传播损耗低至仅1.07 dB/cm，并且对于短至0.9 cm的SSMW长度，实现了高达~1.12×10 ppm的灵敏度。
