QEPAS sensor in a butterfly package and its application.

Molecular gases are highly relevant in healthcare, production control, safety, and environmental monitoring. They often appear in small concentrations. The measurement of trace gases has increasingly become a key technique in those domains. Quartz-enhanced photoacoustic spectroscopy (QEPAS) is a suitable method that can provide the required low detection limits in such applications at comparatively low cost and small size. For mobile implementation, the size of an entire sensor unit matters. In this paper, we present a QEPAS sensor that fits into a standard butterfly package, its characterization, and its application on CH4 and CO2.

High speed external cavity diode laser concept based on a resonantly driven MEMS scanner for the mid-infrared region.

The rapid detection of trace gases is of great relevance for various spectroscopy applications. In this regard, the technology of external cavity diode lasers (ECDLs) has firmly established itself due to its excellent properties. Outside of the laboratory environment, however, these still have some restrictions, especially with regard to high acquisition rates for sensitive spectroscopy applications and mode-hop-free tuning. In this article, we present our innovative GaSb-based ECDL concept, in which a resonantly driven microelectromechanical system actuator is used. With this, a defined frequency range can be tuned extremely fast and without mode hops. Results of the characterization and its use for the rapid detection of trace gases are presented.

Single mode GaSb diode lasers for sensor applications in a long wavelength regime.

The wavelength, λ, range of 1.8 µm≤λ≤3.5 µm contains strong spectral absorption lines of many gases used in health, industry, safety, and medicine and whose sensitive and quantitative detection is desirable. However, the performance of InP diode lasers markedly deteriorates beyond λ∼2 µm. In this paper we present new results on developing tunable high power single mode laser diodes based on the GaSb material system with emission in the wavelength range of 1.8 µm≤λ≤2.2 µm.