Analog electro-optical interface for spectral analysis

An analog electro-optical interface has been studied, which uses the well known field effect of index modulation in thin homeotropic layers of nematic liquid crystal, achieved under a. c. electric field. Such a device is able to present in real-time 64 analog samples of an electric signal in a few milliseconds on a coherent optical set. By means of this interface, electric signals such as electro encephalograms, engine vibrations or SONAR signals can be spectrally analyzed in real-time by optical Fourier transform.