The first measurements of selfphase modulation and nonlinear absorption in a GaAs/GaAlAs multiquantum well (MQW) waveguide near the halfbandgap resonance are reported. An intensitydependent refractive index coefficient n2 of 9 × 10/W and a twophoton absorption coefficient of 0·15cm/GW at l·55 μm wavelength for TM light were obtained. This corresponds to an intensityindependent figure of merit of 24 rad phase change in one nonlinear absorption length, high enough to allow the implementation of subpicosecond alloptical switches at 1·55μm wavelength.
- Optical switching
- Semiconductor devices and materials
ASJC Scopus subject areas
- Electrical and Electronic Engineering