Abstract: A liquid crystal (LC) polarization modulator segment (216, 218) includes a monitoring device (220). The monitoring device (220) includes a polarized reference light source (222), located at an LC polarization monitor input, and polarized light detector (224), located at an LC polarization monitor output. If the reference light having the correct polarization is received at the detector (224), an indication of the switch state is provided. Alternatively, if the polarized detector (224) includes orthogonal polarizers (230A, 230B) provided for two separate light detectors (232A, 232B) both the desired polarization, and the opposite polarization, may be monitored to determine whether a failure exists in the segment. If the reference light is detected having the opposite polarization (instead of or in addition to the correct polarization) or no light is detected, the segment (or the monitor) is not operating correctly.

Abstract: A method and a system for routing cells in an ATM switch. The switch which is input buffered, employs a multiplicity of crosspoint switch planes operating simultaneously in parallel, and whose outputs are combined by an output-buffered second stage. A traffic controlling or path assignment switching stage disposed before the crosspoint switch planes improves performance in the presence of correlated traffic. The switching stage may either control the traffic randomly or adaptively. Input concentration and output expansion functions within the switch are also disclosed. The use of an "unfair" or a predictable preference contention resolution device (CRD) in each of the crosspoint switch planes is possible in another embodiment of the invention. Advantages of the method and system include linear growth with large N in the size and complexity of both the switching circuits and the contention resolution circuits.

Abstract: A flat panel display is disclosed which comprises a row backlight assembly, e.g. a vacuum fluorescent device, and a column shutter assembly, e.g. a ferroelectric liquid crystal device, in front of the row backlight for forming luminous images. Color is achieved in the display by providing varying phase retardation of light passing through the ferroelectric shutter assembly. This is done by selectively varying the thickness of the ferroelectric liquid crystal at adjacent columns so as to correspond to the primary colors required to form a color display.