Voltage-controlled nonlinear optical effects in a twisted nematic liquid crystal cell bounded by dichroic polarizers

Summary form only given. We report the study of the nonlinear transparency effect given by the light-induced creation of an isotropic droplet in a twisted nematic liquid crystal cell bounded by two dichroic polarizers. It is well known that a couple of crossed (parallel) polarizers is opaque (transparent). However, if we insert a /spl Pi//2 twisted nematic liquid crystal cell between them the behavior of the device is reversed since the cell, because of the adiabatic following of the light wave traveling along the twisted structure, acts as a /spl Pi//2 polarization rotator, so that the device is transparent (opaque) for crossed (parallel) polarizers.