DYNAMIC HOLOGRAPHIC SPECTRAL EQUALIZATION FOR WDM

We report a new technique for active management of wavelength division multiplexing (WDM) channels in an optically amplified telecommunicati ons system, based on a polarization-insensitive holographic in-line wa velength filter. Results are presented for the control, amplification and equalization of five WDM channels spaced by 4 nm, Input signal pow er variations of 8.5 and 2.0 dB are reduced to 0.4 and 0.3 dB, respect ively, by switching between two equalising holograms in 5 ms, with sig nals experiencing gains of up to 3.3 dB while undergoing equalization, An unused channel and amplified spontaneous emission noise from the e rbium-doped fiber amplifier (EDFA) have also been suppressed by greate r than 18 dB, This is the first demonstration of active holographic sp ectral equalization for WDM.