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Simulation and optimisation of terahertz emission from InGaAs and InP photoconductive switches

J. Lloyd-Hughes·E. Castro-Camus·M. B. Johnston
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Abstract

We simulate the terahertz emission from laterally-biased InGaAs and InP using a three-dimensional carrier dynamics model in order to optimise the semiconductor material. Incident pump-pulse parameters of current Ti:Sapphire and Er:fibre lasers are chosen, and the simulation models the semiconductor's bandstructure using parabolic Gamma, L and X valleys, and heavy holes. The emitted terahertz radiation is propagated within the semiconductor and into free space using a model based on the Drude-Lorentz dielectric function. As the InGaAs alloy approaches InAs an increase in the emitted power is observed, and this is attributed to a greater electron mobility. Additionally, low-temperature grown and ion-implanted InGaAs are modelled using a finite carrier trapping time. At sub-picosecond trapping times the terahertz bandwidth is found to increase significantly at the cost of a reduced emission power.

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J. Lloyd-Hughes, E. Castro-Camus, M. B. Johnston. 2005-11-17. Simulation and optimisation of terahertz emission from InGaAs and InP photoconductive switches. https://doi.org/10.1016/j.ssc.2005.09.037

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