B.S.T.J. brief: Experimental verification of ultra-wide bandwidth spectra in double-clad single-mode fiber

The low-loss and low-dispersion properties of single-mode fibers make them obvious choices for wide bandwidth system applications with very long repeater spans. This brief describes the fabrication procedure and transmission properties of a double-clad single-mode fiber which is capable of wide bandwidth (greater than 100 GHz-km for laser sources with 4-nm emission bandwidths) transmission over the widest wavelength range (1.45 μm to 1.73 μm) thus far reported in the literature. This range completely covers the lowest-loss wavelength window for fused-silica optical fibers. Double-clad lightguides
^1–4
were formed by using an inner cladding to form an index well between the core and a pure silica outer cladding. A computer-aided analytical procedure was used to choose the proper fiber diameter so that waveguide dispersion effects could be used to cancel material dispersion at predetermined wavelengths.
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