Orientation and thickness dependence of contrast and brightness in Gd2(MoO4)3light valves

Bistable light valves comprising single crystal gadolinium molybdate have been proposed which utilize either the interchange of fast and slow directions in c-cut plates or the alteration of extinction directions in oblique sections upon ferroelectric switching. Several device configurations of each type are analyzed for brightness and contrast as functions of crystallographic orientation and thickness of the ferroelectric plate. The results facilitate quantitative comparisons among devices and predict the sacrifice in optical performance incurred when thickness is reduced to lower the drive voltage required for switching. For equivalent optical performance, the switching voltage should be 43 percent higher in valves of the extinction-direction type. The analysis predicts that no oblique section exists for which display brightness at maximum contrast is higher than that obtainable on a c-cut section of equal thickness.