LITHIUM NIOBATE OPTICAL ELEMENT

摘要

PURPOSE:To stably obtain an optical element having satisfactory resistance to damage by light by using a substrate cut and worked from a crystal so that light is transmitted in the resulting optical element in a specified direction to the direction of growth of the crystal. CONSTITUTION:When a substrate or an optical element is cut from an Mg doped LiNbO3 single crystal, the direction of cutting is requlated to <= 30 deg. from a right angle. The cut substrate is used so that light is made incident on the substrate in a direction nearly perpendicular to the direction of growth of the single crystal. Since light can be made incident in a direction in which the concn. of Mg is uniform and the substrate has a uniform refractive index by a simple means, optical elements having stable operating characteristics and high resistance to damage by light can be formed in a high yield.