Multispan inline and adaptive group delay ripple equalization concepts @ 40 Gb/s with optical FIR-filters

We presented an analytical solution for equalizing the impact of GDR by modeling the inverse system and demonstrated by simulations that optical FIR-filters can act as an excellent equalizer concerning GDR at 40 Gb/s. We compared concepts with inline and adaptive compensation. With fixed dispersion compensated fibre Bragg gratings (DCFBGs), the inline setup could only compensate for GDR. As the adaptive setup could equalize as well for GDR, residual dispersion and self phase modulation (SPM) at the same time, fixed DCFBGs in combination with adaptive optical FIR-filters result in better performance than tunable DCFBGs. This concept provides a group delay ripple and SPM mitigated tunable dispersion compensating module based on fixed DCFBGs and optical FIR-filters capable for high speed optical transmission systems.