A Si Optical Modulator Based on Fano-Like Resonance
Han Du, Weiwei Zhang, Wei Cao, David J. Thomson, Callum G. Littlejohns, Xingzhao Yan, D. T. Tran, Mehdi Banakar, Graham T. Reed
Abstract
In this letter, we present an experimental demonstration of a Si optical modulator based on Fano-like resonance, which is the first of its kind in the literature. The Fano-like resonance is obtained through weak coupling between two optical resonators in the prototype device and a PN junction is designed for carrier-depletion type electro-refractive modulation. 20 Gb/s data rate on-off keying (OOK) is obtained experimentally on the prototype device. Compared with a ring resonator modulator with a similar optical resonance linewidth, a Fano-like resonance based modulator can potentially have a higher extinction ratio (ER) because the Fano-like resonance has an asymmetric spectrum line shape and the line shape on one side can be sharper than the Lorentz resonance line shape of a ring resonator.