In recent years the importance of lasers in optical gas sensing has been continuously increasing. Tunable Laser Absorption Spectroscopy (TLAS) has proven to be a versatile tool in modern environmental analysis. In the mid-infrared wavelength region between 3 and 6 µm, which is of high interest for sensing applications, Interband Cascade Lasers (ICL) can provide monomode continuous wave (CW) emission at room temperature. We present the simulation, design and manufacturing of distributed feedback (DFB) laser devices based on this concept, with focus on devices that target specific, technologically and industrially relevant, wavelengths with low energy consumption. Finally application-grade devices from 3 to 6 µm are presented. CW operation above room temperature and tuning ranges of 11 nm with Side Mode Suppression Ratios (SMSR) greater 30 dB were achieved.
Tunable Laser Absorption Spectroscopy in the mid-infrared wavelength region, especially between 3 and 6 µm, is of great interest for high performance gas sensing applications. Interband Cascade Lasers can provide monomode continuous wave (cw) emission above room temperature in this wavelength range. We present the simulation, design and manufacturing of application-grade distributed feedback laser devices based on this concept. The fabricated devices successfully target specific, technologically relevant, wavelengths in cw operation above room temperature with low energy consumption. Output powers above 5 mW, high Side Mode Suppression Ratio around 30 dB and tuning ranges of up to13 nm were achieved.