Design and performance analysis of SOA-MZI-based Tbps all-optical gray converters with M-ary DPSK coded binary, gray, and octal inputs

Abstract

We propose three different types of all-optical code converters with high data rates of 1 Tbps based on a semiconductor optical amplifier in Mach–Zehnder interferometer configuration. The gray code is a cyclic code, which is more suitable for accurate representation of numbers, error detection, correction, and rounding of decimal quantities. The OR and XOR logic gates are the key structures in the proposed design to convert binary inputs to gray (BITG), binary coded decimal (BCD) inputs to gray (BCDTG) and octal inputs to binary (OCTB) outputs. The output of proposed all-optical gray code converters is verified for all three types of input representations. The bit error rate is negligible for all the input combinations. The obtained average extinction ratio for all-optical code converters are 87, 84, and 78 dB. The optimum value of quality factor up to 59 is achieved at 0.1 A, ±5, and 0.3, respectively, for the injection current, linewidth enhancement factor, and optical confinement factor. For the first time to the authors’ knowledge, all-optical gray code converters yield high data rates of 1 Tbps for the semiconductor optical amplifier-Mach–Zehnder interferometer configurations using the M-ary differential phase-shift keying modulation scheme.