Current-controlled group delay using a semiconductor Fabry–Perot amplifier

We present a demonstration of a current-controlled group delay using a semiconductor waveguide Fabry–Perot optical amplifier operated in reflection. Current injection allows us to tune the resonant wavelength as well as provide the gain required for all-pass reflection, which leads to group delay tunability with relatively small power variation. We show very good agreement between our experimental data and theoretical results, which are analogous to waveguide-coupled active ring resonators.