High Sensitive Hydrogen Sensor Based on a Reflective Metallic Grating with Palladium Filled

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发表日期：

2024年11月30日

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Lu Wang,
Wenzhe Huang,
Yunfei Zou,
Yinqiao Li,
Dawei Ruan,
Chen Wang,
Song Wang,
Gang Song

摘要

We investigate a hydrogen sensor based on surface plasmon polaritons (SPPs) involving palladium material at room temperature. The sensor is composed of a reflective silver grating and Pd bars in its slots. Pd material can absorb H $_2$ $_{2}$ at room temperature and its index can change greatly. Finite difference time domain method is used to calculate the reflection spectrum of our proposed structure. We mainly focus on the difference of the reflection spectra ( $\varDelta R$ $Δ R$ ) for structures between before and after H $_2$ $_{2}$ absorbed. The results show that the curve of $\varDelta R$ $Δ R$ versus incident wavelength is a non-zero line. The maximum value of $\varDelta R$ $Δ R$ (max $\varDelta R$ $Δ R$ ) can reach to 0.13 when H $_2$ $_{2}$ concentration increases from 0 to 4 percent. max $\varDelta R$ $Δ R$ is non monotonic with the increase of the width of Pd bar for each structure with different period. This shows the competition between the coupling caused by Ag grating and Pd and the dissipation of the system. The slot of Ag grating can be seen as a Fabry–Perot (FP) cavity with a low quality factor. By changing the hight of the slot, the length of FP cavity is changed and max $\varDelta R$ $Δ R$ appears cosine oscillation. Our proposed structure is quite sensitive to H $_2$ $_{2}$ , and has good applications in H $_2$ $_{2}$ sensor.