Freitag, 24. Juni 2016, 14:00 - 15:30 iCal

Univ.-Prof. Dr. Gottfried Strasser/

Technische Universität Wien

"Monolithically Integrated Mid-Infrared Nanosensors"

Seminarraum 2 der Fakultät für Chemie
Währinger Straße 42, 1090 Wien


This talk aims to give a short introduction in the field of quantum cascade devices with a strong focus on quantum cascade lasers (QCLs) and quantum cascade detectors (QCLs). A bi-functional QC structure will be presented [1,2], that can be operated in two modes, as coherent light emitter as well as intersubband detector, depending on the bias applied to the structure [3].

This opens the way to on-chip sensing solutions with a high inte-gration density [4]. Liquid sensing at room tem-perature with a mono-lithic integrated sensor was achieved by a QCL, a dielectric loaded Surface Plasmon Polari-ton (SPP) waveguide as interaction section of the infrared light with the liquid, and a QCD.

To demonstrate gas sensing with the same technology a surface emitting and detecting sensor was processed using the very same heterostructure material. A distributed feedback ring quantum cas-cade laser is integrated on-chip with a detector element. The surface emitted light is collimated, guided through a gas cell, back reflected by a flat mirror, focused, and detected by the sensor element on the very same device. The surface operation mode enables for comparable long interaction lengths as needed for gas absorption measurements [5].

[1] Schwarz, B. et al., Sensors 13, 2196, 2013 [2] Schwarz, B. et al., Appl. Phys. Lett. 107, 071104, 2015 [3] Schwarz, B. et al., Nat. Commun. 5, 4085, 2014 [4] Ristanic, D. et al., Appl. Phys. Lett. 106, 041101, 2015 [5] Harrer, A. et al., Scientific Reports 6, 21795, 2016


Fakultät für Chemie


Brigitte Schwarz
Fakultät für Chemie der Universität Wien