Herbert Looser of FHNW/IGN, expert in nonlinear optics
Markus Sigrist of ETHZ/D-PHYS/IQE/LSSL, expert in Gas and liquid spectroscopy
There is an increasing demand for sensitive, selective, fast and portable detectors for trace components in gases and liquids, e.g. due to increasing concerns about atmospheric pollutants, and a need for improved medical screening capabilities for early detection of diseases and drug abuse. In that context, the project IrSens aims at building a versatile platform based on optical spectroscopy in the near and midinfrared range. Indeed, techniques based on optical absorption offer the possibility to realize a non-invasive and highly sensitive detection platform. It allows to probe the vibrational frequencies of the targeted molecules - most of which are located in the near and mid-infrared range, and to obtain an unambiguous signature of the investigated gas or liquid.
The idea is to create a photonic sensor platform with high performance and reliability which will leverage on the new source, detector and interaction cell technologies to create a new sensor element with vastly improved performance and lowered cost. These improvements will be demonstrated further by the incorporation into two pilot applications, the first one aiming at the demonstration of sensing in the gas phase, the second one in the liquid phase.
The compact sensing platform for gases under development is based on multipath absorption cells with various compact semiconductor light source and detector types. Infrared absorption spectroscopy can be used to detect a wide variety of gases. To demonstrate its suitability for breath analysis, the first part of this project is focused on the detection of helicobacter pylori . a bacteria responsible for gastric ulcers . by means of isotopic ratio measurements in exhaled CO2. The integrated sensing platform for liquids is based on waveguiding and surface measurement technologies and the same sources and detectors as for the gas sensing. The idea is to couple the sources to a silicon-based optical module where the liquid analyte will flow through a built-in microfluidic channel. This is intended to be used mainly in bio-medical applications with an emphasis on drugs and doping agents detection in human fluids: specifically, a first targeted demonstrative application for this sensor would be the cocaine detection in human saliva.
A CMOS Compatible Ge-on-Si APD Operating in Proportional and Geiger Modes at Infrared Wavelengths A. Sammak, M. Aminian, L. Qi, W. D. de Boer, E. Charbon, L.K. Nanver; International Electron Device Meeting (IEDM), Washington, DC, (12, 2011)
CO2 isotope sensor using a broadband infrared source, a spectrally narrow 4.4 ?m quantum cascade detector, and a Fourier spectrometer D. Hofstetter, J. Di Francesco, L. Hvozdara, H.-P. Herzig, M. Beck; Applied Physics B (0, 2011)
Infrared Attenuated Total Reflection (IR-ATR) Spectroscopy for Detecting Drugs in Human Saliva K.M.-C. Hans, S. Müller, M.W. Sigrist; Drug Testing and Analysis (0, 2011)
Intra-cavity patterning for mode control in 1.3?m coupled VCSEL arrays L. Mutter, B Dwir, A. Caliman, V. Iakovlev, A. Mereuta, A. Sirbu, E. Kapon; Optics Express (0, 2011)
Norland optical adhesive (NOA81) microchannels with adjustable wetting behavior and high chemical resistance against a range of mid-infrared-transparent organic solvents Ph. Wägli, A. Homsy, N.F. de Rooij; Sensors and Actuators B (0, 2011)
Wafer-fused heterostructures: application to vertical cavity surface-emitting lasers emitting in the 1310 nm band A. Sirbu, V. Iakovelv, A. Mereuta, A. Caliman, G. Suruceanu and E. Kapon; Semicond. Sci. Technol. (0, 2011)
Mid-infrared quantum cascade detectors for applications in spectroscopy and pyrometry D. Hofstetter, F.R. Giorgetta, E. Baumann, Q. Yang, C. Manz, and K. Köhler, Applied Physics B, (0, 2010)
Quantum Cascade Detectors F.R. Giorgetta, E. Baumann, M. Graf, D. Hofstetter, Q. Yang. C. Manz, K. Köhler, H.E. Beere, D.A. Ritchie, E. Linfield, G. Davies, Y. Fedoryshyn, H. Jäckel, M. Fischer, J. Faist, and D. Hofstetter, Journal of Quantum Electronics, (0, 2009)
There is an increasing demand for sensitive, selective, fast and portable detectors for trace components in gases and liquids, e.g. due to increasing concerns about atmospheric pollutants, and a need for improved medical screening capabilities for early detection of diseases and drug abuse. In that context, the project IrSens aims at building a versatile platform based on optical spectroscopy in the near and midinfrared range. Indeed, techniques based on optical absorption offer the possibility to realize a non-invasive and highly sensitive detection platform. It allows to probe the vibrational frequencies of the targeted molecules - most of which are located in the near and mid-infrared range, and to obtain an unambiguous signature of the investigated gas or liquid.
