Optical 4-bit binary to gray and gray to binary code conversion has been demonstrated. The encoders are designed by implementing XOR gates in optical domain. Phase modulation in Mach–Zehnder interferometer has been exploited to achieve results at considerably high data rates of up to 60 Gbps. Also, the designs, being reversible in nature, will amount to less power consumption when embedded in an optical network. Performance parameters of the design, such as Q factor and extinction ratio, are analyzed based on simulation results carried out using comprehensive design suite OptiSystem-13.
In this paper a study on modulation formats like non return to zero (NRZ), return to zero (RZ) and carrier suppressed
return to zero (CSRZ) in terms of generation, dispersion analysis and performance at the receiver end has been done for a standard single mode fiber (SMF) of fixed length and data rate. The principle of external modulation through a Mach Zehnder Modulator (MZM) is been employed for the generation of the various formats. Linear effect or dispersion performance of formats alone is considered here. A dispersion compensation technique based on dispersion compensation fibers (DCF) that improves the performance of the optical link is also studied. The performances have been analyzed in terms of bit error rate (BER) and quality factor (Q-factor). The study reveals that RZ exhibits superior performance over the other formats in terms of dispersion tolerance, BER and Q-factor values. It is also shown that by introducing a DCF module system performance can be improved.