Performance of 10 Gb/s lightwave systems based on lithium niobate Mach-Zehnder modulators with asymmetric Y-branch waveguides

The dependence of the transmission performance of 10 Gb/s systems on the splitting ratio of the Y-branch waveguides in a lithium niobate Mach-Zehnder modulator is assessed theoretically for single arm and dual arm modulation formats. When the splitting ratio is optimized, dual arm modulation using a push-pull configuration offers better dispersion limited performance than a conventional negative chirp modulator with symmetric Y-branch waveguides and single arm modulation (/spl alpha/ parameter of -1). The push-pull configuration also has the advantage of reducing the requirement on the amplitude of the modulating signals.>