A Si Optical Modulator Based on Fano-Like Resonance

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.