This dissertation explores new laser spectroscopic methods for gas sensing to increase the precision in present and future compact sensor platforms. Comprehensive modeling of the laser diode and sensor system is presented, and metrics for performance evaluation are derived. The developed multi-harmonic detection and hollow capillary fiber based Zeeman spectroscopy are shown both practically and theoretically to improve sensor precision. Moreover, developed sensors for air quality (CO₂ and H₂O) and for fire detection (CO) are critically evaluated for the application.     «

This dissertation explores new laser spectroscopic methods for gas sensing to increase the precision in present and future compact sensor platforms. Comprehensive modeling of the laser diode and sensor system is presented, and metrics for performance evaluation are derived. The developed multi-harmonic detection and hollow capillary fiber based Zeeman spectroscopy are shown both practically and theoretically to improve sensor precision. Moreover, developed sensors for air quality (CO₂ and H₂O) a...     »