“…Since the drawing temperature has a strong effect on the optical loss in SMFs [1,3,5], all of the fibers were drawn at the same, lowest possible temperature, 1860°C, which prevented disruption due to the strong tension and made it possible to minimize the optical loss. To study the effect of the shape of the RIP across SMFs, several series of preforms with graded (smooth) and step index profiles were prepared by MCVD.…”