Photonic crystals for sensor-applications, in particular sensing of gases

• Applicant: Dr. Armin Lambrecht
• Subject Area: Condensed Matter Physics
• Term: from 2001 to 2004
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5317474

Many gases (and liquids) exhibit characteristic absorption lines in the mid infrared wavelength region (3-20µm). So spectroscopic-based sensor techniques play a major role in processing and production measurement (e.g. CO and CO2 measurement in the automotive market) but with the major drawback of high costs for such systems. The aim of this project is to evaluate and develop sensors on the basis of photonic crystals for spectroscopic detection of gases. The advantage of such systems over conventional ones could be the possibility of miniaturization, integration, batch processing and thus low-cost versions of such sensor systems. Macroporous silicon is intended to be used as photonic crystal material, from which structures for wavelength in the mid infrared region can be fabricated with great reproducibility. Theoretical calculations are necessary regarding the structure layout (tailoring of the sensor geometry for the desired wavelength, layout of the coupling regions). Beside the experimental verification of the effects predicted from theory it is the main goal of this project to work out practical solutions for sensors even at this early stage so that future, more application oriented projects, (e.g. BMBFfunded) could build upon.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1113: Photonic Crystals