Extension of the Measurable Wavelength Range for a Near-Infrared Spectrometer Using a Plasmonic Au Grating on a Si Substrate

Numerical Study on a Bound State in the Continuum Assisted Plasmonic Refractive Index Sensor

Plasmonic sensors have attracted intensive attention due to their high sensitivity. However, due to intrinsic metallic loss, plasmonic sensors usually have a large full width at half maximum (FWHM) that limits the wavelength resolution. In this paper, we numerically investigate and propose a dielectric grating-assisted plasmonic device, leveraging the bound states in the continuum (BIC) effect to suppress the FWHM of the resonance. We initiate quasi-SP-BIC modes at 1559 nm and 1905 nm wavelengths by slightly tilting the incident angle at 2° to break the symmetry, featuring a narrow linewidth of 1.8 nm and 0.18 nm at these two wavelengths, respectively. Refractive index sensing has also been investigated, showing high sensitivity of 938 nm/RIU and figure of merit (FOM) of 521/RIU at 1559 nm and even higher sensitivity of 1264 nm/RIU and FOM of 7022/RIU at 1905 nm.

Optical Detection Method for High Aspect Ratio Microstructures

High aspect ratio microstructures (HARMS) are of great importance for many application fields. Many defects are generated during the fabrication processes, especially in line microstructures, and it is necessary to examine the quality of the structures after each process. However, there is no suitable efficient nondestructive detection method to monitor microstructures during the fabrication processes. In this paper, an optical detection method capable of detecting the structures by analyzing the reflection of light on the line HARMS is proposed. According to the image of reflected visible light, this method can determine whether there are defects in structures, so as to realize efficient detection. Preliminary simulations and experiments have been performed to confirm the feasibility and validity of the proposed method for detecting line microstructures. This method is expected to obtain more information about microstructures by further optimizing system parameters.

Editorial for the Special Issue of Selected Papers from the 9th Symposium on Micro-Nano Science and Technology on Micromachines

The Micro-Nano Science and Technology Division of the JSME (Japan Society of Mechanical Engineers) promotes academic activities to pioneer novel research topics on microscopic mechanics [...].