Nonlinear effects of an external intensity modulator on the performance of an optical up-conversion system for millimeter-wave over fiber applications

摘要

The nonlinear effects of an electro-optic intensity modulator in an optical up-conversion system for millimeter-wave (mm-wave) over fiber applications are investigated in this paper. In the analysis, general nonlinearities caused by the Mach-Zehnder modulator used for optical up-conversion are analyzed and discussed. Electrical fields of the up-converted optical signal are expressed in power series form, which are widely used in electronics in expressing memoryless nonlinearity. Harmonic distortion and inter-modulation distortion generated in an optical up-conversion, a scheme recently proposed for mm-wave over fiber applications, are analyzed in detail. One-tone and two-tone measurements are performed to validate the analyses based on our newly proposed optical up-conversion configuration.