| 摘要 |
PURPOSE:To measure a refractive angle with high accuracy by reflecting transmitted light by a rotary mirror which can freely rotate around an axis parallel with a transparent circular cylindrical body and measuring the rotating angle at which the rotary mirror reflects the light in one direction. CONSTITUTION:The incident light (a) on a base material 3 of an optical fiber is refracted and is passed through (b), (c) from which the light is reflected at (d) by the rotary mirror 21 inclined by thetaa from a reference position OO' and is projected as parallel reflected light beams through (e) of a condenser lens 22 to theta' of a detector 23. The light a' passes b', c', is reflected by the mirror 21' inclined by thetaa' from the position OO' and is projected through e' of the lens 22 to theta' of the detector 23. The rotating angles thetaa, thetaa' of the mirror 21 are the refractive angles of the light rays (a), a' respectively. Namely, the refractive index distribution of the base material 3 can be determined by measuring the rotating angle with the respective scanning light rays. The refractive angle is, therefore, measured by moving only the incident optical system without moving a matching cell 5 holding the base material 3 which is the object to be inspected if the sizes of the mirror 21 and the lens 22 are taken into consideration. |
