QUASI-PHASE-MATCHED 2ND-HARMONIC GENERATION FROM ASYMMETRIC COUPLED QUANTUM-WELLS

Optical second-harmonic generation of visible light in a superlattice of asymmetric coupled GaAs quantum wells has been measured for the first time to our knowledge. The orientation of the asymmetric quantum wells was periodically reversed such that the quantum-well contribution to the radiated second-harmonic signal was quasi-phase matched when it was excited by a lamba=1.319 mum fundamental in the reflection geometry. The second-harmonic intensity generated in this superlattice was approximately 3.6 times that generated in a homogeneous GaAs reference. The measured superlattice second-harmonic susceptibilities are \chi(yzy)(2) = 1.5 x 10(-11) m V-1 and \chi(zyz)(2)\ = 1.3 x 10(-11) m V-1.