Single grating period quantum cascade laser array with broad wavelength tuning range

A distributed feedback quantum cascade laser array emitting at λ∼ is reported. Utilising a ridge width dependence on emission wavelength, the array of laser ridges exhibited a tuning range in excess of 230 nm over the temperature range of 140 to 380 K. Singlemode operation with sidemode suppression ratios of / spl ges/25 dB and a combined tuning coefficient of -0.1 cm^-1 K^-1 are demonstrated.