Some methods of signal processing using optical techniques

In recent years optical techniques have been utilized in a number of different signal processing systems. Certain types of operation such as multiplication and Fourier transformation are easily implemented using optical techniques, and this paper describes a selection of signal processing systems which incorporate some optical components and have possible applications in many fields such as seismology, radar, sonar, speech recognition and vibration analysis. Particular attention has been directed towards systems in which the interaction of acoustic waves and monochromatic light is used to provide a dynamic means for modulating the light with signal waveforms, and some adaptations of existing systems of this type are proposed.