PURPOSE: To focus waveguide light on a prescribed position precisely by changing the temperature of an optical waveguide and a lens part formed on a part of the optical waveguide to change the focal distance of the lens part.
CONSTITUTION: Y-cut IdNbO3 crystal is used as a substrate 1 and Ti is thermally diffused on the surface of the y-cut to form the optical waveguide. Subsequently, Nb2O5 is RF-sputtered like a dome by using a mask having a circular truncated cone-like opening to form a thin film lens 3. Since the refractive index of the Nb2O3 is 2.24W2.26 and higher than that of LiNbO5, light transmitted through the optical waveguide 2 is attracted into the thin film lens 3 and converged. A buffer layer 4 is formed on the thin film lens 3 and then a HFB2 film is vapor-deposited as a heater electrode 5. When the thin film lens 3 is heated by the heater electrode 5, the refractive index of the thin film lens 3 is changed by a thermooptical effect and the focal distance can be changed. Thus, the waveguide light can be focused precisely on a prescribed position by controlling the electric field between the electrodes of the optical waveguide lens, so that the error of the focal distance at the production of the lens can be corrected.
OGURA SHIGETAROU
MATSUMOTO KAZUYA
Next Patent: JPS6032028