(b) Draw the chromatic dispersion curve of a standard single mode optical fibre and indicate the zero dispersion wavelength of the fibre. Explain briefly the two mechanisms that contribute to the total chromatic dispersion of a single mode fibre. When we want to change the zero dispersion wavelength, which type of dispersion can be changed and how? If the operating wavelength of a single mode fibre is changed from 1300mm to 1550mm, will the bending loss of the fibre increase or decrease? For normal Silica fibre, what is the main problem if we change the operating wavelength to 3 um