APPARATUS & METHOD FOR DRAWING OPTICAL FIBER HAVING DESIRED WAVEGUIDE PARAMETERS AND FIBER PRODUCED THEREBY

摘要

An apparatus and method for drawing a fiber having desired waveguide parameters, particularly cut-off wavelength is provided. The apparatus is characterized by a temperature measurement means (113) provided near surface (A) of the preform (105), being capable of directly measuring surface temperature of that part of the preform (105) which is outside the furnace; and a programmable logic controller [PLC] (114) connectable to said temperature measurement means (113), and being capable of controlling and maintaining temperature of that part of the preform (105) which is inside the furnace (101) by continuously controlling and maintaining the power supply to heating (elements 104) of the furnace, wherein the PLC (114) is capable of controlling and maintaining power supply to the heating elements (104) by employing equation (1) till the preform completely just enters the furnace Power supply = (start power) x C + (surface temperature of preform which is outside furnace) x (slope term)...... Eqn. (1) an