No abstract

No abstract

We developed a surface-micromachined tunable Fabry-Pérot interferometer for the thermal infrared spectral range of wavelengths 7-12 μm. In this paper, we present the device performance in terms of the optical transmission and the tunability. The device represents the first layout that proved successful in terms of the manufacturing process yield (about 80%). The optical transmission over the wavelengths from 3 to 20 μm is presented with the emphasis on analysing the first-order transmission peak. The transmission band width and the peak height are compared using the existing theory for this type of an interferometer. The deviation from an ideal performance is resolved and partly explained through the known structural unidealities.

Miniaturized spectrometers covering spectral regions from UV to thermal IR are of interest for several applications. For these purposes VTT has for many years been developing tuneable MEMS-based and more recently piezo-actuated Fabry-Perot Interferometers (FPIs). Lately several inventions have been made to enter new wavelengths in the VIS range and enlarge apertures of MEMS devices and also extending the wavelength range of piezo-actuated FPIs. In this paper the background and the latest FPI technologies at VTT are reviewed and new results on components and system level demonstrators are presented. The two FPI technologies are compared from performance and application point of view. Finally insight is given to the further development of next generation devices.

No abstract