Analytical model for calculating the nonlinear distortion in silicon-based electro-optic Mach-Zehnder modulators

Abstract

[EN] In this study, an analytical model for calculating the nonlinear harmonic/intermodulation distortion for RF signals in silicon-based electro-optic modulators is investigated by considering the nonlinearity on the effective index change curve with the operation point and the device structure simultaneously. Distortion expressions are obtained and theoretical results are presented showing that optimal modulator parameters can be found to linearize it. Moreover, the harmonic distortion of a 1 mm silicon-based asymmetric MZI is RF characterized and used to corroborate the theoretical results. Based on the present model, the nonlinear distortion in terms of bias voltage or operating wavelength is calculated and validated by comparing with the experimental data, showing a good agreement between measurements and theory. Analog photonic link quality parameter like carrier-todistortion is one of the parameters that can be found with that model. Finally, the modulation depth is measured to assure that no over-modulation is produced.This work was supported by the funding from the European Commission under project HELIOS (pHotonics Electronics functional Integration on CMOS), FP7-224312. The work of P. Sanchis and J.-M. Fedeli was supported by the funding funding from TEC2012-38540 LEOMIS, TEC2008-06333 SINADEC, and PROMETEO-2010-087. The work of F. Y. Gardes, D. J. Thomson and G. T. Reed was supported by funding received from the UK EPSRC funding body under the grant "UK Silicon Photonics."Gutiérrez Campo, AM.; Brimont, ACJ.; Herrera Llorente, J.; Aamer, M.; Thomson, DJ.; Gardes, FY.; Reed, GT.... (2013). Analytical model for calculating the nonlinear distortion in silicon-based electro-optic Mach-Zehnder modulators. Journal of Lightwave Technology. 31(23):3603-3612. https://doi.org/10.1109/JLT.2013.2286838S36033612312