Tunable Optical Sensor Array (TOSA)
Currently INA carries out TOSA, an innovative joint project which is sponsored by the Federal Ministry of Education and Research
This project aims at investigating tunable optical sensor arrays with high spectral resolution and a wide tuning range. The related technologies are analyzed and optimized as well. On the one hand the sensor array is specified for the visible spectral range (400-700 nm) for applications like highly precise color detection and color control. On the other hand it serves a range of 360-1107 nm, e.g. in order to measure substrate temperatures in thin film deposition processes with high accuracy. Another essential field of application is the spectroscopic identification of biomarkers through the skin. The small dimensions of the sensor array allow its integration into products frequently carried by consumers (cell phones, mp3-players) and therefore permits a fast fitness check through blood analysis.
The optical sensor is fabricated by means of deposition of tunable Fabry-Pérot (FP) filter arrays on optical detector arrays (photo diode rows, CMOS digital camera modules or CCD-rows/arrays).
The cavities of the single FP filters consist of organic materials which are molded to the desired layer thickness by highly precise 3D nanoimprint
. Structuring by means of microsystems technology leads to partial removal of the organic material (sacrificial layer process) resulting in an air gap. By variation of the electric field between the DBR-mirrors the detached top mirror can be actuated electrostatically. This results in a change of cavity thickness, which changes the transmission wavelength of the filter.
Such filters with different cavity thicknesses, i.e. with spectrally complementary tunable ranges of the transmission wavelengths, are integrated on an optical array which permits recording of optical spectra in a wide total tunable range with high resolution.
Joint partners and cooperations: