Effects of injector barrier on performance of terahertz quantum-cascade lasers
An experimental study of the effects of injector barrier thickness on the performance of terahertz quantum-cascade lasers is reported. The injector barrier is varied from 54 to 38 Å in an otherwise identical 3.4 THz laser structure. It is shown that the threshold current density at 10 K increases monotonically from 445 A/cm2 to 1.29 kA/cm2 with reducing barrier thickness. On the other hand, an optimum injector barrier thickness of 44 Å is found to give rise to a maximum lasing temperature of 141 K.
