METHOD AND APPARATUS FOR EXCITING OPTICAL FIBER

• Main Author: HATTORI YASUJI
• Format: Patent
• Language: English
• Published: 25.02.1986
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

PURPOSE:To attain maximum amplitude easily by adjusting the position of a fine movement board so that a core image of an optical fiber and the reflected image of measuring signal light at the incident end surface of the optical fiber are overlapped each other on a monitor. CONSTITUTION:Since light made incident on the clad part of the optical fiber 5 from a light source 17 is leaked out to the external of the optical fiber during its transmission through the optical fiber 5, only a core part is observed as a bright portion at the incident terminal 3 of the optical fiber 5. The core image on the incident terminal 3 is passed through a lens 2, reflected by a half mirror 16, received on an image pickup tube 20 through an image forming lens 18, and displayed on the monitor 21 as an image 22. On the other hand, the reflected light of the measuring signal light 1 at the incident terminal of an optical fiber to be measured is similarly displayed on the monitor 21 as an image 23. Thus, the center of the luminous flux of the signal light 1 coincides with the core center of the optical fiber 5 by moving the fine movement board 4 so that the core image 22 is concentrically superposed to the reflected image 23 on the monitor 21 while observing the monitor 21, so that the maximum excitation can be attained.