Measurement of field-induced refractive index variation in GaAs/AlGaAs superlattice using monolithic Fabry-Perot etalon

The electrorefractive effect in a GaAs/AlGaAs superlattice was measured by using a monolithic Fabry-Perot structure, where the superlattice active region is embedded inside a cavity, formed by two quarter-wave stacks, all grown by molecular beam epitaxy. At the wavelength approximately 7675 AA, there is a large absorption change ( approximately 5400/cm) and an accompanying index change ( approximately 0.015) when the applied field change is approximately 100 kV/cm. In addition, the chirp parameter at this wavelength is less than 1. This result shows that superlattice electroabsorption optical modulation can offer relatively very low chirp.