| 摘要 |
PURPOSE:To lessen connection loss by forming specific grooves by dry etching near the connecting surface of a first waveguide part. CONSTITUTION:Only the points 6a, 6b corresponding to connecting surfaces at the time of butt connection are exposed at a desired width and the other surface parts are coated with a resist 7. After the surface over the entire part is subjected to dry etching, the resist 7 is peeled away. Consequently, only the constituting material of the thin-film body existing right under the exposed surfaces 6a, 6b is etched away and the grooves 8 are so formed as to enclose the first waveguide part A to be formed. The grooves 8 are so formed as to have the depth at which the grooves penetrate the entire part of the core layer 4 and further arrive at the point lower than the front surface 2a of a common lower clad 2 existing thereunder. Then, the dry etching surfaces A1, A2 in the first waveguide part A are formed as perpendicular surfaces which are both flat from the surface of the gap layer 6 clown to the desired depth of the common clad 2. |
