Antimonide-based DFB lasers emitting above 2.6 lm

The mid-infrared 2-2.7 mum region of the electromagnetic spectrum is attractive for trace gas sensing owing to the presence of strong absorption bands of several species of industrial interest and is also well adapted to water measurements and isotopic ratio studies. However, single-frequency and continuously tunable emission is required, thus distributed feedback (DFB) laser diodes are well suited for these gas sensing applications. The low gap materials used give access to the mid-infrared wavelength range (lambda > 2 mum). In recent years, impressive results were obtained on DFB lasers above in this wavelength range with an emission at 2.55 mum and at 2.74 mum. In this Letter, we focus, for the first time to our knowledge, on the fabrication and characterisation of DFB devices operating between 2.6-2.65 mum dedicated to water measurement.