Experimental performance of a fully tunable complex-coefficient optical FIR filter using wavelength conversion and chromatic dispersion.

We experimentally characterize the performance of a continuously tunable all-optical complex-coefficient finite-impulse-response (FIR) filter that exploits nonlinear signal processing (multiplexing and multicasting) and conversion-dispersion-based optical delays. Various length (three and four) optical FIR filters with different tap amplitudes (from 0 to -9 dB), tap phases (from 0 to 2π), and tap delays (~37.4 ps and 25 ps) are realized, showing reconfiguration and tuning capabilities of this FIR filter. The measured frequency responses show close agreement with the theoretical filter responses.