Low threshold step well quantum cascade laser emitting at 3 THz

A resonant-phonon THz quantum cascade laser based on Al
_0.03
Ga
_0.097
As step well is demonstrated. Maximum pulsed operating temperature is 123 K, with threshold current densities as low as 110 A/cm
²
at 10 K and 175 A/cm
²
at 100 K.