THEORETICAL PERFORMANCE OF 10 GB S LIGHTWAVE SYSTEMS USING A III-V SEMICONDUCTOR MACH-ZEHNDER MODULATOR/

The system performance is assessed for 10 Gb/s lightwave systems that use a III-V semiconductor Mach-Zehnder intensity modulator and operate at a wavelength of 1.55 mum with standard single-mode optical fiber. The modulator is modeled by an equivalent circuit and an experimentall y derived functional dependence of the attenuation and phase constants on applied voltage. The influence of the format of the modulating sig nal and the splitting ratio of the input Y-branch waveguide on the chi rp characteristics of the modulator is examined based upon calculation of the receiver sensitivity. Optimum system performance is obtained f or an asymmetric splitting ratio.