| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber axial alignment observing device for highly accurately positioning the axes of at least two optical fibers on their end faces by reducing the cost, size and moving space of an optical system and the cost of a moving mechanism. SOLUTION: In the optical fiber axial alignment observing device 1, at least one parallel planer optical element 50a or 50b is arranged on the optical path of at least one of 1st and second illuminating light beams L1 and L2 in the image side space or object side space of an objective lens 40. Both of an optical path difference between respective optical path lengths of the 1st and 2nd illuminating light beams L1 , L2 between the main point of the lens 40 and 1st and 2nd images I1 , I2 and axis misalignment distances of the 1st and 2nd images I1 , I2 from the optical axis A0 of the lens 40 are eliminated based upon the refractive index of the 1st or 2nd illuminating light L1 or L2 made incident and projected on/from the incident face and out-going face of the element 50a or 50b, the inclined angles of the incident face and the out-going face of the elements 50a or 50b to the 1st or 2nd illuminating light L1 or L2 and thickness between the incident face and out-going face of the elements 50a and 50b. |
