| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus where a refractive-index distribution in an optical system, having a refractive-index distribution symmetric with respect to an axis is measured nondestructively and with high accuracy. SOLUTION: The circumference of a specimen 41 is covered with a matching solution 43, having a refractive index of n2 which agrees nearly with that of a clad part at the outside of the specimen 41 composed of an optical fiber, whose refractive index in a core part at the inside is n1 and whose refractive index in the clad part at the outside is n2. The matching solution 43 is filled into a matching cell 42 which houses the specimen 41. An incident window 44 on which measuring waves are incident so as to irradiate the specimen 41 through the matching solution 43 and an emissive window 45, by which the measuring waves transmitted through the specimen 41 are radiated to the outside through the matching solution 43 are installed at the matching cell 42. A first condensing lens 40 as a first condensing optical system and a second condensing lens 46 as a second condensing optical system are installed respectively at the front of the incident window 44 and at the back of the emissive window 45.
|
