This paper introduces the technology ditfuulty of thin-diameter（165 μm in diameter） ultra-low bending-loss optical fiber and the methods to adjust the structure design of optical fiber preform.It uses MCVD to manufacture the optical fiber preform

transfomis G.657 fiber drawing equipment

adjusts the conditions of drawing process

produces geometrical-stable thin diameter optical fiber and carries out performance test of the optical fiber.Comparing this optical fiber with G.657 fiber in mechanical properties

andbending properties

it shows that thin-diameter ultra-low bending-loss optical fiber can meet the requirements of G.657 standards in conventional index

also it still has ultra-low bending-loss performance under a 100-circle bending condition.