title: Quasi phase matching in GaAs--AlAs superlattice waveguides through bandgap tuning by use of quantum-well intermixing.
abstract: We report the observation of second-harmonic generation by type I quasi phase matching in a GaAs-AlAs superlattice waveguide. Quasi phase matching was achieved through modulation of the nonlinear coefficient chi((2))(zxy), which we realized by periodically tuning the superlattice bandgap. Second-harmonic generation was demonstrated for fundamental wavelengths from 1480 to 1520 nm, from the third-order gratings with periods from 10.5 to 12.4microm . The second-harmonic signal spectra demonstrated narrowing owing to the finite bandwidth of the quasi-phase-matching grating. An average power of ~110 nW was obtained for the second harmonic by use of an average launched pump power of ?2.3mW .
authors: A
authors: A
authors: Saher Helmy
authors: D C
authors: DC
authors: Hutchings
authors: T C
authors: TC
authors: Kleckner
authors: J H
authors: JH
authors: Marsh
authors: A C
authors: AC
authors: Bryce
authors: J M
authors: JM
authors: Arnold
authors: C R
authors: CR
authors: Stanley
authors: J S
authors: JS
authors: Aitchison
authors: C T
authors: CT
authors: Brown
authors: K
authors: K
authors: Moutzouris
authors: M
authors: M
authors: Ebrahimzadeh