A high resolution fiber optics communications system (FOCS) for analog signals has been designed, built, and tested at the Frank J. Seiler Research Laboratory, USAF Academy, Colorado. The FOCS consists of a small transmitter and receiver pair and an optical waveguide. A combination of voltage-to-voltage (V /F/V) and pulse width modulation (PWM) is used to reconstruct a ±1 0 volt analog output signal from an identical ±10 volt analog input signal. A digital output is easily obtained since the data transmission is pulsed. The FOCS is equally applicable to free-space infrared communications. The advantages of fiber optics have not previously been available for general purpose data acquisition because their application has been limited to dedicated digital systems and to low resolution, high frequency video systems. Data collected on a very general V/F/V system are presented to give the designer information on V/F/V system dynamics at fre-quencies much higher than those considered to be in the V /F /V system's useful range for data acquisition and communication purposes. These data show that the V/F/V process may be useful for servo loop applications at much higher frequencies than it is for data acquisition and communication applications.