Chromatic Dispersion Compensation using Optical All Pass Filters

The purpose of this paper is to experimentally study Optical All Pass Filters (OAPF) and optimize the value of distance of origin from poles (r). Using the value of transfer function of optical all pass filter which is of 2 order we found the factor of numerator and denominator. In this work, we took the value of ̳r‘ as 0.660 and the angular position (w0) as 0.390. The power taken as 18dBm. When the power of laser is increased beyond 18dBm, poor results of BER and Q-factor were obtained, because non linearity‘s are added. The phase response of OAPF is designed to cancel the phase delay of single mode fiber (SMF) which is the main cause of Chromatic Dispersion (CD). The simulation of the mathematical model of the optical communication system at 10 Gb/s employing the proposed OAPF is presented. The different values of optical fiber lengths starting from 100km to 180 km. At operating wavelength of 1.55 μm, the CD is 17ps/nm-km which is the amount of broadening in picoseconds that would occur in a pulse with a spectral width of optical source as one nanometer, while propagating through one kilometer of fiber. There is an improvement in BER with equalizer up to 10 in 1 channel, up to 10 in 2 channel and up to 10 in 3 channel as compared without equalizer. The improvement in Q-factor for the fiber length of 180 km is up to 4 times in 1 channel, up to 5 times in 2 channel and up to 3 times in 3 channel. Keywords––single mode fibre, chromatic dispersion, four wave mixing, dispersion compensation, optical communication.