Abstract: Disclosed is a wide-band dispersion controlled optical fiber. The optical fiber enables the use of optical signals in various wavelength regions in a wavelength division multiplexing mode communication network by controlling the position of the zero dispersion wavelength, and enables long distance transmission by controlling dispersion slope and bending loss. Furthermore, there is an advantage in that the optical fiber enables not only short distance transmission but also middle/long distance transmission using a single type of optical fiber because the optical fiber is controlled to have negative dispersion values in the O-band wavelength region and positive dispersion values with small deviations in the C-band and L-band wavelength regions.

Abstract: Disclosed are a method and apparatus for overcladding a glass rod with a glass tube. The method includes (a) preparing a sealing tube, provided with a hole formed through the central portion thereof, (b) attaching the sealing tube to an upper end of the glass tube, (c) aligning the glass rod with the glass tube such that the glass rod is inserted into the sealing tube and (d) sealing an upper end of the sealing tube by heating an outer wall of the sealing tube.

Abstract: Disclosed is a wide-band dispersion controlled optical fiber. The optical fiber enables the use of optical signals in various wavelength regions in a wavelength division multiplexing mode communication network by controlling the position of the zero dispersion wavelength, and enables long distance transmission by controlling dispersion slope and bending loss. Furthermore, there is an advantage in that the optical fiber enables not only short distance transmission but also middle/long distance transmission using a single type of optical fiber because the optical fiber is controlled to have negative dispersion values in the O-band wavelength region and positive dispersion values with small deviations in the C-band and L-band wavelength regions.