Pyrooptic converter, a new device for wavelength conversion of electromagnetic radiation

Abstract

The operation of a “pyrooptic” converter based on the combined utilization of a pyroelectric detector and an electrooptic light modulator is demonstrated. In the device investigated the intensity changes of an electromagnetic radiation incident to a triglycine sulphate pyroelectric detector induce a pyroelectric signal, and this signal controls the intensity of a light beam passing through a liquid crystal light modulator, i.e. a modulated radiation is converted into modulated light. With impedance matching between the two elements of the converter but without amplifying the pyroelectric voltage a minimum detectable intensity of radiation of 0.3–0.6 W/m², and an intensity required for total opening of the light modulator of 17–47 W/m² is found in the chopper frequency range of 5–20 Hz.