A LIGHT CHOPPER FOR INFRARED DETECTION UTILIZING FERROELECTRIC LIQUID-CRYSTAL

The transient light scattering mode effect due to polarization inversi on of ferroelectric liquid crystal was used in the experimental design of a light chopper for infrared detection. In order to understand the light scattering effect, the relationship between the driving conditi ons and pulse response speed of domain switching was analyzed. Light m odulation was optimized by adjusting the duty cycle in rectangular wav e driving. This method made it possible to improve the light scatterin g response due to electric field inversion, resulting in high-efficien cy light modulation. It was found that the improvement of light scatte ring response occurred because the recovery speed from the scattering state to the nonscattering state was accelerated by the electric field inversion. By observing the generation-growth-extinction process of s cattering objects, the relationship between the change in the liquid c rystal structure and light scattering was obtained. The wavelength dep endence of the light modulation-voltage characteristic and the tempera ture dependence of the field of view and the degree of modulation were elucidated. (C) 1997 Scripta Technica, Inc.