We have calculated the current response of a sub-micron GaAs optical s
witch to light pulses of two different intensities and of wavelengths
799 nm, 734 nm and 633 nm using the Monte Carlo method. We found that
the effect of increasing the energy of the incident radiation was to c
ause a significant lengthening and broadening of the initial transient
current response, whilst the effect of increasing the intensity of in
cident radiation was to delay the rate at which the device could be cl
eared of charge carriers. We have examined effects of displacement cur
rent in addition to the carrier current. The net current shows interes
ting structure which may have been observed experimentally.