Abstract: The invention relates to a single-mode optical fiber used in a long wavelength band range for optical telecommunication. The core and the cladding of this optical fiber contain P.sub.2 O.sub.5 as a dopant selected to lower the deposition temperature and to hasten the deposition speed so as to result in low absorption loss.

Abstract: A matrix-addressed liquid crystal display device including a matrix-addressed display section is provided. The display section comprises a pair of optically transparent plates each of which having on one surface a plurality of parallel strip electrodes optically transparent and deposited through an optically transparent spacer, said pair of plates being parallelly arranged so that the electrodes will be inside and mutually intersect at right angles so as to form row and column electrode groups of a matrix, and a cholesteric phase liquid crystal filled between the respective plates, which liquid crystal being such that when a voltage applied to the electrodes is above a threshold level the molecular axes of the liquid crystal are aligned in the direction of electric field due to the voltage applied.