Demonstration of Optical FEC Coding Scheme With Convolutional Code Consisting of a Signal Source

Abstract

In this letter, we experimentally demonstrated an all-optical forward error correction (FEC) coding scheme with the $(7, 5)_{8}$ convolutional code using a single signal source to compensate time-dependent noise. The proposed coding scheme was comprised of optical XOR gates, delay lines, and optical wavelength converters, which are based on four-wave mixing in highly non-linear fibers. The temporal waveforms of the optical FEC coding scheme were experimentally achieved for 10 Gb/s return-to-zero differential phase shift keying (RZ-DPSK) signals modulated with $2^{23}-1$ , and the obtained idler signals accurately corresponded to the $(7, 5)_{8}$ code between any input signals. Under the optimized conditions of operational wavelengths, the proposed scheme theoretically offered 4.0 and 3.5 dB net coding gains for the conditions of BER $\geq 10^{-8}$ and BER $= 10^{-9}$ , respectively, owing to its small power penalties.