High speed GaAs and GaInAs high radiance light emitting diodes

High radiance high speed homojunction GaAs and GaInAs VPE LEDs are shown to have frequency responses composed of two parts, a slow response, with cut off at ∼ 100 MHz and a fast response with cut off > 1.5 GHz. These responses are shown to arise from hole recombination in the n-side and electron recombination in the p-side of the junction respectively. The devices are of a sufficiently high radiance that about 80µW can be launched C.W. into a 0.16NA, 85µm core step index fibre at 500MHz, using microlens coupling.