Dispersion minimisation in single-mode fibres between 1.3 ¿m and 1.7 ¿m

The possibility of minimising total dispersion near 1.3 ¿m in truly single-mode fibres is examined. It is also shown that dispersion-free single-mode fibres can be obtained at 1.7 ¿m. More generally, we observe that the total dispersion can be cancelled at any wavelength between 1.3 ¿m and 1.7 ¿m.