Go!Foton’s Thermally Expanded Core Fiber has an enlarged mode field diameter (MFD) obtained by heating a conventional singlemode fiber locally at high temperature (~1300 to 1450 ⁰C). The core expansion rate depends on heating temperature and heating time. TEC Fiber has the feature that although thermal diffusion changes the refractive index profile, the normal frequency does not change and hence the single mode condition is maintained through the process.
Features