Mode switching and singlemode tuning in two-segment distributed feedback quantum cascade lasers

摘要

Two-segment distributed feedback (DFB) GaAs/AlGaAs bound-to-continuum quantum cascade lasers emitting at ～10.8 μm were fabricated and investigated. Reversible switching between two different DFB modes by current injection control yielding sidemode suppression ratios up to > 23 dB is reported. Two different devices were fabricated for which the distance between the different DFB modes is 1.5 and 2.5 cm~(-1), respectively, and quasi-continuous tuning over a range of > 9 cm~(-1) (105 nm)between 120 and 250 K was observed.