General design approach to multichannel fiber Bragg grating
A general technique to design a multichannel fiber Bragg grating (FBG) is reported, which incurs the minimum refractive change of the core. The grating thus designed can compensate a large number of wavelength channels with different dispersion and different spacing. It also enables the design of a multichannel optical add-drop multiplexer (OADM), and at the same time, the channels are dispersion compensated. The technique is extended to linearize the group time delay of the grating by the inclusion of the third-order chirping factor of each channel. Finally, the fabrication tolerance of such FBG is discussed