The Variable Fiber Optical Splitter splits an incoming optical signal among two output optical fibers with a continuously variable ratio controlled by an electrical input voltage from 0 to 5V. When the electrical control signal is at zero, the splitter is at a standard version of 100:0; and changes to 0:100 when the input signal is 5V. The zero voltage ratio can be made at any pre-determined ratio with special orders. The device is bidirectional, transmitting light in both directions simultaneously. The all-solid-state crystal design eliminates the need for mechanical movement. The Variable Fiber Optic Splitter has passed highest reliability qualifications, including Telcordia and mill-spec. It is designed to meet the most demanding requirements of ultra-high reliability, fast response time, and continuous operation. The unit is mounted on a driving board having a control signal input SMC connector and a wall plug-in power supply. Available with several electronic drivers having performance optimized for various repetition rates.