Compact Tuneable Light Module

Astghik Chalyan (ESR1) is developing a miniaturized tunable light source covering a spectral range of 360 nm to 1700 nm and a linewidth down to 10 nm. Its purpose is for calibration of the xCLASS spectroscopic modules, and as a specialized light source for spectroscopic measurements. The module consists of a low-cost broadband light source with a dedicated tunable optical filter. A proof-of-concept had been demonstrated experimentally for the visible range with a DLP-based light source implementation. Further research is focusing on the development of the full system, which includes two wavelength segments, each of which is based on a Fastie-Ebert optical layout, including a digital micromirror device (DMD) chip as the wavelength selector. Current work is in the implementation of the housing assembly and performance testing.

Miniaturized Optical Spectrometer

Artem Shcheglov (ESR2) is modeling, designing and fabricating a miniaturized micro-spectrometer and demonstrate its proof-of-concept. The utilization of a customized imaging diffraction grating in the spectrometer is a promising approach bringing additional freedom for the miniaturization of the system. This means the grating should be suitable for mass-production. Therefore, the research is focusing on the fabrication and replication of diffraction gratings using state-of-the-art techniques. He has performed experimental replication of flat diffraction gratings using a diamond tooled mold. The possibility of using two-photon polymerization for fabricating the mold is investigated as well. For the design part of the research, he has proposed several optical configurations of the miniaturized spectrometer, one of which is planned to be used for the final proof-of-concept, where the optical design will be merged with the gained knowledge about grating fabrication.

Integrated Image sensors

Anas Gasser (ESR3) is selecting and integrating the imaging sensor used to convert the diffracted light after the grating into useful spectral data. This is mainly done by designing the electronics interfacing and controlling the sensor and trying to minimize them to meet all size, mechanical, spectral and thermal specifications of the spectrometer system. He is also testing and verifying the operation of the whole spectrometer system in different application domains. With a digital micromirror device (DMD), a single point detector could be used. The DMD is used to scan all the spectral lines and project them on the detector. Another example is by using high-speed time-gated CMOS imaging sensors, time-resolved fluorescence spectroscopy could be achieved. Thus, it is possible to measure the fluorescence lifetime at different wavelengths over the fluorescence emission spectrum.