Mid-IR Sensing Using External Cavity Quantum Cascade Lasers

Commercially available quantum cascade semiconductor materials continue to mature. When integrated into external cavity quantum cascade laser (ECqcL T) geometries, these laser systems are now providing near-continuous coverage throughout the entire 3 - 13 mu m regime. Such coverage enables molecular detection systems to enjoy high sensitivity and selectivity. Individual lasers have been demonstrated to provide > 320 wavenumbers of tuning. Wide tuning ranges have also been demonstrated at wavelengths in the 3 - 4 mu m regime. In addition, phase continuous (mode-hop-free) tuning allows for extremely high resolution spectroscopy to be performed throughout the mid-IR. Daylight Solutions will review the most up-to-date results regarding wavelength coverage, tuning range and power levels achieved from ECqcL T systems. Daylight will also provide recent results in sensitivity and coverage from their multi-species Swept Sensor T and photoacoustic detection platforms.