PURPOSE: To easily manufacture a waveguide type lens by a two-beam interference exposing method by using an optical waveguide which decreases in effective refractive index gradually and a diffraction grating on the waveguide which has a constant period.
CONSTITUTION: A buffer layer 23 of SiO2 is formed on a substrate 24 and etched with fluoric acid, etc., into a specific tapered shape. A waveguide layer 22 is formed thereupon and then the optical waveguide layer 22 decreases gradually in effective refractive index in the propagation direction of light. A silicon nitride film is deposited further thereupon and the diffraction grating 21 with a 0.6μm constant period is formed by the two-beam interference exposing method and a mask exposing method. When waveguide 25 with 0.8μm is made incident thereupon, it is converged on a convergence position 28. Thus, the waveguide lens is easily manufactured by the conventional two-beam interference exposing method.
SERIZAWA HIROMOTO
HORI YOSHIKAZU
MATSUI YASUSHI
ODANI JIYUN
