Research On Integrated Devices Of Photonic Crystal Electro-optic Modulation And Coarse Wavelength Division Multiplexing

With the rapid development of the information industry,the demands for the performance of communication systems continue to increase,and there is an urgent need for research on communication systems with larger transmission capacity and higher transmission speed.At present,the research on devices with a single function has become mature,but how to maintain the good performance of a single device and cascade multiple devices on the same chip still needs more research.Communication systems have the requirements of "small size","large capacity","large bandwidth" and "integration",and silicon-based optoelectronic integration technology has become an important method to solve the problems faced by current communication systems.Silicon-based optoelectronic integration has the advantages of low power consumption,low cost,high integration,and high compatibility with CMOS technology.The electro-optic modulator and the wavelength division multiplexer are responsible for the information loading and capacity expansion respectively in the communication system,so the research on the integration of these two modules is essential.In this paper,an integrated device of electro-optic modulation and coarse wavelength division multiplexing based on silicon-based photonic crystal ring resonator is proposed.The device is composed of two modules of electro-optic modulation and coarse wavelength division multiplexing.The electro-optical modulation module is based on a ring resonator and a side-coupling structure,and realizes the "on" and "off" modulation of the device through the plasma dispersion effect.Coarse wavelength division multiplexing module is based on ring resonator,side-coupling structure and double reflective wall structure.By reasonably selecting the parameters of ring resonator and the distance from cavity to reflective wall,the multiplexing function of specific working wavelength is realized.In the integrated device,the modulation module and the coarse wavelength division multiplexing module are cascaded,and the cascaded devices are adjusted to obtain the optimal performance of the integrated device and realize dual-wavelength modulation and download.In addition,the tapered waveguide is cascaded at the connection between the nanowire waveguide and the photonic crystal plate of the integrated device,so as to reduce the loss when the nanowire waveguide is cascaded with the photonic crystal wire defect waveguide.Through design,optimization and simulation analysis,the integrated device can realize modulation and wavelength division multiplexing functions with operating wavelengths of 1530nm and 1550nm.The simulation results show that the modulation depth of the integrated device at 1530nm and 1550nm is both 0.99,the insertion loss is 0.48dB and 0.59dB,the channel crosstalk is-34.39dB and-56.44dB,and the extinction ratio is 23.73dB and 22.78dB,respectively.The modulation rate is about 18.18GHz,and the device footprint is 48.42 μm × 10.22 μm × 0.22μm.The integrated device has good performance and compact structure,and can be used in a highspeed and large-capacity optical communication system of CWDM and data centers.