| 摘要 |
PURPOSE:To detect whether or not an optical fiber is normal with high accuracy by detecting far field images at two points of laser light emitted by a microlens on the tip of the optical fiber and finding the divergence angle of the laser light, and finding the optical radius of curvature of the lens by applying the propagation rule of a Gaussian beam. CONSTITUTION:A core 1 made of quartz to which B, F, P, Ge, etc., are added is covered with a clad 3 of pure quartz to form the optical fiber 1, which is provided with a microlens structure 5 of 10-30mum in radius a the tip on a laser light projection side. Then this fiber 1 is mounted on a control table 32 movably in an X-, a Y-, and a Z-axial direction, a light emitting device 31 is connected to the incidence side, and the projection side is set opposite an infrared camera 40 on a support table 33, so that an image from it is displayed on a CRT 43 through a video controller 42. Thus, the widths WA and WB of the half-value total angles of Gaussian type far field images 50 and 51 obtained by image processing and the beam divergence angle theta are calculated and used to decide whether or not the radius of curvature of the lens 5 is within a reference range. |
