Design And Implement Of Electro-optic Modulator On Silicon Based On Microring Resonator

Electro-optic modulator is the key device in the optical fiber communication (OFC) network. The electro-optic modulator applied widely in the OFC currently is made by the materials of LiNbO3 orⅢ-Ⅴcompound, the process of which is not compatible with the standard COMS process and leads the device to high price. Silicon distribution is broad in the earth and very cheap. Silicon-based technology is mature so that the cost of producing an electro-optic modulator will be decreased strikingly if they are made by silicon. On the other hand, the traditional electric interconnection is facing the bottleneck now. There is a tendency that the electrical interconnection will be replaced by the optic interconnection. The research and implement of electro-optic modulator based on silicon waveguide will pull the development of the optical interconnection on silicon chip. And the electro-optic modulator based on silicon can be integrated with electronic integrated circuit. From this point, the research of electro-optic modulator based on silicon waveguide is meaningful.In this paper, the mechanism of the electro-optic modulator on silicon based on microring resonator (MRR) is elaborated. The principle and characteristics of the MRR are investigated by the transfer matrix method. The effect of various factors to the MRR is analyzed. The influence of the coupling and decay coefficient to the MRR is explained in detail. In order to avoid the mode dispersion, the single polarization and single mode rib optic waveguide is designed in this paper by using the BPM module of the waveguide designing soft named Rsoft. The transmission loss, bend loss and coupling loss between the fiber and waveguide is simulated by the FDTD module of Rsoft. The test result shows that the MRR with narrow 3dB bandwidth value and high extinction ratio is implemented. The 3dB bandwidth value and the extinction ratio for the MRR are around 0.158nm and 9dB respectively. The free spectra range (FSR) is about lOnm. The coupling is loss to the fiber is around 5.5dB/facet. The fundamental quasi-TE mode is only promised to transmit in the waveguide. All these work are prepared very well for the design and implement of electro-optical modulator. The electrical structure, which is a pin diode, is analyzed and simulated in this paper as well. The simulation tool is called ISE-TCAD which is produced by the Synopsys. The pin diode match to the need of the electro-optic modulation is designed. Finally, the high performance pin diode is combined to the MRR, which implements an electro-optical modulator on silicon. The test result shows that the electro-optical modulator can operate at a speed 20Hz with a modulation depth 11.723dB.