Circuit arrangement of a digital optical waveguide testing device

摘要

The device is used in conjunction with an optical waveguide fault location device which operates according to the pulse-echo method, and enables a statement about the presence of breaks in optical waveguides. The optical waveguide is to be examined for impermissible defects. Of special interest are faults in the vicinity of plugs, which occur, for example, in production or in the practical use of the optical waveguides. Furthermore, the total number of reflecting joints is determined. If a break is present in a plug, this device is therefore intended to determine in which of the two plugs of the optical waveguide this lies. In so doing, use is made of the effect that strong reflections occur at breaks, because of Fresnel reflection and that the Fresnel reflection can be strongly suppressed at optical waveguide ends by matching to the surrounding medium by means of immersion liquids. The measuring results are shown with indicators. The block diagram is reproduced in Figure 1. <IMAGE>