Wide wavelength tuning of Ga As ∕ Al x Ga 1 − x As bound-to-continuum quantum cascade lasers by aluminum content control

Tuning of the emission wavelength in Ga As ∕ Al x Ga 1 − x As bound-to-continuum quantum cascade lasers with different Al mole fractions ( x ) is reported. By varying x in the range of 0.37-0.52, a shift of the emission wavelengths of over 4 μ m has been observed. Using this method, laser action in the range of 11.2 - 15.3 μ m at temperatures T ⩾ 260 K has been demonstrated with a record value of ∼ 340 K for GaAs based QCLs operating at 13.5 μ m .