Theory of three-cladding dispersion-compensating fibre (DCF) with negative
dispersion slope is analyzed, suggestions of adjusting various parameters i
n DCF are given, and a novel overclad technology is proposed. At the same t
ime spinning when drawing was ap plied to lower polarization mode dispersio
n in DCF, and finally modified chemical vapour deposition technology was al
tered for preparation of the advanced DCFs.