Study on the loss mechanism of the expand beam fiber connector

The basic principle expand beam fiber connector is firstly introduced. Then its loss mechanism is analyzed,including the variable loss and the invariable loss. The variable loss comes from the error of leveling for cells of the system,such as the loss of radial excursion,the loss of portrait excursion and the loss portrait obliquity. In all loss,the radial excursion is the greatest,then the loss of portrait obliquity,the invariable loss and the loss of portrait excursion. The invariable loss comes from the materials and surface processing of the system itself,such as the loss of Fresnel,ball aberration,diffraction,chromatic aberration and absorb.Finally,the efficient methods to reduce loss are presented.