A light beam on a single optic fiber carries time division multiplexed information originating from multiple sensors driven from a single light source. An optical switch apparatus coupled in series between the source and the sensors switches the light beam of the source between ON and OFF states. The switch apparatus includes an electro-optic switch and an acousto-optic switch coupled in series with the electro-optic switch. A controller and drivers for the electro-optic and acousto-optic switches produce in an appropriate time sequence control signals resulting in a desired ON and OFF time of the light beam being switched.