Ultrafast Carrier Dynamics And Resonant Inter-Miniband Nonlinearity Of A Cubic Gan/Ain Superlattice

We investigate the linear and dynamical nonlinear optical properties of a superlattice composed of ultra-narrow n-doped GaN/A1N quantum wells. Owing to huge band offsets, the structures feature a broad inter-miniband transition in the telecom window at 1.55 pm. Resonant pump-probe experiments directly reveal uhrafast intersubband relaxation occurring within <100 fs. We estimate an associated third order nonlinear optical susceptibility of Im(chi((3))) 1.1 x 10(-20) m(2)/V-2. The polarization and angular dependences of the optical response confirm the nonlinearity as originating from inter-miniband transitions in the heterostructure. (C) 2015 AIP Publishing LLC.