mode optical fiber has low attenuation

THE INVENTION REGARDS FIBER OPTIC. THE INVENTION IS ONE mode fiber DOUBLE DUCT INCLUDING HEART 11 12 INNER SHEATH WITH REFRACTIVE INDEX LOWER THAN THAT OF THE HEART AND AN OUTER JACKET WHICH REFRACTIVE INDEX IS BETWEEN THE HEART AND THE INLAND DUCT. REDUCED ON MITIGATION OF FIBER TO THE BIGGEST WAVELENGTH TAKING WORTH AT LEAST 6.5 TO THE RELATIONSHIP BETWEEN THE RADIUS OF THE INNER LINER AND RADIUS OF THE HEART. APPLICATION TELECOMMUNICATIONS OPTICAL LONG DISTANCE.