Abstract
This paper reports on the measurement of material spectra of acrylic plate and glass plate using a plasmonic spectrometer. Portable spectrometers are needed for more diverse applications of spectral analysis. This spectrometer has gold diffraction gratings on a n-type silicon wafer and is suitable for miniaturization because it completes the spectroscopy on the surface of the photodetector by using surface plasmon resonance. However, it has not been applied to spectral measurement of materials other than gases. Here, we measured the transmission spectra of acrylic and glass plates by the spectrometer with a plasmonic photodetector. We measured the responsivity to near-infrared light over a range of angles and at different wavelengths. We also measured the photocurrent due to the light under spectroscopy and performed matrix calculations for spectroscopy. The transmission spectra calculated were compared with the transmission spectra obtained with a conventional Fourier transform infrared spectrometer. The maximum error in the transmission spectrum was 22 % from 1250 nm to 1410 nm and the results calculated for this wavelength range were accurate. In conclusion, the spectrometer and continuum light can measure material spectra in the range. This research contributes to the realization of compact sensing system using the spectrometer that can analyze various material.
