Design and fabrication of metasurface for MEMS narrowband infrared light source

Efficient, compact and low-cost mid-infrared light source is very important for gasing sensing. In this work, we demonstrated a metasurface structure with an absorption peak at an infrared wavelength of 7.35 μm, which can be used for narrowband infrared emission. Integrating it onto MEMS heaters can achieve a narrowband infrared light. By deliberately choosing the dimensions of metasurface, the MEMS mid-infrared light source could have narrowband emission at different wavelengths. This type of infrared light source can eliminate the need for optical filtering components, which is beneficial for the miniaturization and integration of infrared gas sensors. The metasurface was designed and simulated using CST software. The sample with absorptivity peak at wavelength of 7.35 μm was fabricated, which was characterized using Fourier Transform Infrared(FTIR) microscope. The infrared absorptivity curve of the metasurface can well match the infrared absorption region of SO₂ gas.