Polarization and field dependent two-photon absorption in GaAs/AlGaAs multiquantum well waveguides in the half-band gap spectral region

H. K. Tsang, R. V. Penty, I. H. White, R. S. Grant, W. Sibbett, J. B.D. Soole, H. P. LeBlanc, N. C. Andreadakis, E. Colas, M. S. Kim

Research output: Contribution to journalArticle


We report the observation of two photon absorption which is strongly dependent on the applied electric field and the optical polarization. At 1.55 μm wavelength, the two-photon absorption coefficient of the GaAs/AlGaAs multiquantum well (MQW) waveguides for transverse-magnetic light is about seven times lower than for transverse-electric polarized light and changes by a factor of approximately 4 for a change in applied direct-current electric field of ∼140 kV/cm. Ultrafast nonlinear refraction causing phase changes of over π radians without appreciable excess loss is observed. These measurements demonstrate that GaAs/AlGaAs MQW waveguides could be successfully used for subpicosecond all-optical switching near half-band gap, at wavelengths corresponding to the 1.55 μm optical communications band.

Original languageEnglish
Pages (from-to)3440-3442
Number of pages3
JournalApplied Physics Letters
Issue number26
Publication statusPublished - 1 Dec 1991

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this