Coherent Optical Solutions Using AWGs
White Paper
ABCs of Arbitrary Waveform Generators
Don’t let your fiber optical network be the bottleneck of your communications system. Fiber is the backbone of network systems. Today’s optical infrastructures must support an ever-increasing demand for more data over existing lines. This white paper will take a look at applied data coding schemes that can solve bottlenecks in your communications network to keep up with the growing demand for speed and data.
The Beginning
Optical data transport started with the simplest and cheapest digital coding schemes: return-to-zero (RZ) and non-return-to-zero (NRZ) on-off-keying (OOK). The signal is ideally a sequence of ones (power-on) and zeros (power-off). This concept faces a limit when transfer rates reach 40 Gb/s. Above this rate, spectrally broadened channels start to overlap with the neighboring channels, resulting in crosstalk and degradation of the modulated information. The industry moved to more complex modulation schemes like quadrature phase shift keying (QPSK) to reduce the dispersion impairments seen in OOK schemes.