Simultaneous demonstration of multiple optical tapped delay line functions on multiple data channels

An optical-tapped-delay-line (OTDL) can implement various processing functions on data that is transmitted over an optical network, including format conversion, complex filtering, and pattern recognition. Previous demonstrations of OTDL functions have either processed: (i) one data channel with one or more OTDL functions, or (ii) multiple data channels with one OTDL function per channel. In this work, we experimentally demonstrate three OTDL functions simultaneously on two optical data channels to obtain six optical data outputs. The inputs include: (i) two quadrature-phase-shift-keying (QPSK) channels, and (ii) two on-off-keying (OOK) channels. In each case, delayed data copies and pumps encoded with the OTDL function weights undergo nonlinear wave mixing in a periodically poled lithium niobate (PPLN) waveguide. Six optical data outputs are simultaneously generated at six different frequencies. In the QPSK case, the average symbol correctness over 3072 symbols is: (i) ~99.5% at 7.5-Gbaud and ~98.8% at 10-Gbaud for format conversion, (ii) ~98.1% at 7.5-Gbaud and ~94.3% at 10-Gbaud for complex filtering, and (iii) 100% at both baud rates for pattern recognition. In the OOK case, the average symbol correctness at 7.5-Gbaud is ~99.8% for format conversion, ~99.9% for complex filtering, and 100% for pattern recognition.