Seminars Archive

Towards fully-integrated and CMOS-compatible photonic sensing in the Mid-IR

Abstract
Chemical and molecular sensing find applications in many fields, spanning from monitoring the quality of air, food, lubricants or batteries to the analysis of automotive emissions or even to medical applications (to name just a few). Most of such applications require the capability to identify and quantify the concentration of specific molecules in gaseous or liquid samples. Spectroscopy in the mid-infrared is a natural tool for molecular sensing, due to the specific “fingerprint” absorption bands of most molecules in this spectral region. Spectroscopic techniques show typically high sensitivity and selectivity, together with the possibility to measure at high rates. Thus, one natural way towards miniaturized portable molecular sensors is to combine mid-IR spectroscopy with micro- and nano-photonics. Integrated photonics in the mid-IR, however, presents several challenges. Cheap and powerful narrowband mid-IR sources are either bulky or difficult to integrate into a silicon platform. Additionally, the efficiency of room-temperature detectors in the mid-IR is limited compared to their counterparts in the visible or near-IR. Within this framework, I will present our recent results towards the development of waveguide-based, fully-integrated silicon sensors for mid-IR chemical sensing of CO2 on a chip.