Tunable optical equalizer for 40-Gbps intensity-modulated signal using PLC-based finite-impulse-response filter

Using a PLC-based 16-tap optical FIR filter, we demonstrate tunable optical equalization for 40-Gbps intensity-modulated signals. Such equalizer compensates for both intensity distortion due to tight filtering and phase distortion due to ±100-ps/nm chromatic dispersion, giving significant receiver-sensitivity improvement.