ELEMENT FOR CONVERTING WAVELENGTH OF LIGHT

摘要

PURPOSE:To manufacture an element for converting the wavelength of light with satisfactory stability to temp. and high efficiency by forming a grating in a crystal of a nonlinear substance such as an LiNbO3 crystal. CONSTITUTION:A grating 6 whose refractive index changes periodically and an optical waveguide 7 having a partially increased refractive index are formed in a single crystal of a nonlinear substance. For example, titanium is thermally diffused in a Y plate 5 of an LiNbO3 crystal cut perpendicularly to the Y-axis of the crystal to form a filmlike grating 6 whose refractive index changes periodically in the forward direction of light, and an optical waveguide 7 having an increased refractive index is formed on part of the grating 6 by an ion exchange method using K, Ag, H or the like. Light enters one end of the waveguide 7 and emerges from the other end.