| 摘要 |
PURPOSE:To improve measurement sensitivity by making an adjustment so that light power in one main axial direction is maximum as to rear scattered light generated beyond a point at which a connection is expected to be made, or so that light power in another main axial direction is minimum. CONSTITUTION:Two main axes of polarization maintaining optical fibers A and B are denoted as (x) and (y), and then a polarizer 2 is aligned to the (x) axis and an analyzer 5 is aligned to the (y) axis. Consequently, rear scattered light detected by a photodetector 6 is extremely small because there is a little mode coupling between the main axes (x) and (y). While alignment is insufficient at a connection point, part of the energy of an optical pulse signal which propagates along the main axis (x) after passing through the connection point is coupled with the main axis (y), so rear scattered light in the mode of the main axis (y) is generated beyond the connection point and detected by the photodetector 6. When rear scattered light beyond the connection point which is polarized in the direction of the main axis (y) is minimized by rotating end parts around cores mutually, the current coupling is minimum and a connection is only made in the state. |
