Characterization Of Planar Antenna Fabricated An GaAs Epilayers Containing As Clusters For Picosecond Short-pulse Applications

When one grows GaAs using normal molecular beam epitaxy (MBE) conditions except at low substrate temperatures, excess As can be incorporated into the epilayer. The amount of excess As is strongly dependent on the substrate temperature during MBE. Upon annealing these epilayers at temperatures of 600°C or higher, the excess As precipitates. The final As cluster density and average diameter is a function of the time and duration of this anneaI1. We will designate this composite material consisting of As clusters in a GaAs matrix as GaAs:As. In this paper we present experimental results which assess the performance of antennas that are fabricated on GaAs:As and are switched photoconductively with a picosecond pulsed laser system.