In this paper, an all-optical 1x2 switch is demonstrated based on gain modulation of injection locked Fabry-Perot laser diode (FP-LD). The control circuit generates set and reset states, which are used to perform 1x2 switch function. The switch output state is maintained once it starts to operate, whether the control signal is present or absent. In the experiment, with extinction ratio of 13.2 dB the switch output eye diagram is recorded.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.