SIMULATION OF THE NEAR-FIELD OF SINGLE-MODE FIBERS BY MEANS OF A MICROWAVE MODEL

In order to verify the agreement of the conventionally used approximations for the field equations of the fundamental mode of a fiber and to study the near field in the vicinity of a discontinuity, a microwave model of a single-mode fiber is designed and constructed. At this waveguide, which works at frequencies of about 10 GHz, the field distribution can be measured with a small microwave probe. Using a semi-automatic level- and wavefront-recorder the field pattern of the radiating fiber end, as well as that in the vicinity of a gap, a displacement or an angle, is plotted and discussed.