文摘
We have proposed a general design concept of a wavelength division multiplexed optical 16-QAM modulator using silicon micro ring modulator (MRM) and presented the characteristics of such modulator with preconditioned electrical inputs. We have shown using numerical simulations the need for optimization of the preconditioned radio frequency (RF) input voltages for high speed operation. Studies have been carried out for optimizing the rise-time and the fall-time of the symbol phases for a given baud-rate, keeping the power consumption of the modulator to its minimum value. We have addressed the effect of recombination lifetime of the carriers, coupling coefficients in the MRM structure, and cross-talk from adjacent MRMs on the performance of the proposed WDM 16-QAM modulator. It has been presented that after proper optimization of preconditioned RF input, the proposed modulator produces 2 dB optical signal-to-noise ratio (OSNR) penalty (with respect to back-to-back condition) over approximately ±1340 ps/nm and ±340 ps/nm dispersion window for 5GS/s and 10GS/s symbol rates respectively for WDM transmission.