Effective-area measurement in a single-mode optical fiber

The effective area (Aeff) of the single-mode fiber is an important measurement parameter. It is the area of the cross section of the beam into the fiber. Therefore, their evaluation requires the measurement of the field distribution in the fundamental mode LP01. In this work, we present a method to measure the effective area in the single mode fiber (SMF) and dispersion shifted fiber (DSF) using a 1550 nm wavelength in the input beam. The Direct Far Field (DFF) scan technique was used, making an accurately measure of the angular distribution of the intensity of the field from the single-mode fiber. The near field and far field for a circularly symmetric fiber are related through the inverse Hankel transform of order zero. Since this cannot be resolved analytically, we process our data obtained experimentally with a numerical integration to evaluate Hankel transform. If we know the near field, we can obtain the effective area from these data and equally of numerical integration.