Microelectromechanical infrared spectrometer: Master's thesis

PURPOSE: To characterize the operation of a low-cost infrared spectrometer based on a MEMS Fabry-Perot interferometer and a thermopile detector. MATERIALS AND METHODS: The transmission spectra of tunable microelectromechanical (MEMS) Fabry-Perot interferometers were simulated and measured. Electrical control of the components was characterized. The performance of thermopile detectors was characterized and compared to commercially available components. Electronics for controlling the interferometer and the detector components were developed. A laboratory demonstrator spectrometer based on the components was constructed. Spectra of sample liquids were measured with the demonstrator and a commercial spectrometer. RESULTS: The optical performance of the Fabry-Perot interferometer components corresponded well to the simulations. Some of the components were electrically defective, but a solution for improving the processing of the components was found and tested. The thermopile detectors were found to have performance on par with or even better than commercial thermopiles. The constructed spectrometer performed as expected, having a lower spectral resolution than the laboratory spectrometer, but being able to distinguish the sample liquids. CONCLUSION: A low-cost infrared spectrometer based on MEMS components is feasible. The performance of the components was mainly in line with the simulations.