Research On Silicon-based Thermo-optic Modulator Based On Two-dimensional Materials

The emerging two-dimensional materials represented by graphene,with unique physical properties,have shown great research potential in many scientific fields.Transition metal dichalcogenide is a large branch of two-dimensional materials.Its band gap is adjustable with the number of layers and it has a higher carrier mobility,all of which make it have good research and application prospects in optoelectronic devices.Platinum diselenide is a relatively new member of this branch.Its theoretical carrier mobility can be comparable to black phosphorus,at the same time,the smaller band gap and broader light absorption spectrum enable its application scenarios to be extended to the near-infrared band.The silicon-based micro-ring resonator is an important component in the silicon-based photonic circuit,and it can be applied to filtering,modulation,and switching.Micro-ring modulators based on the thermo-optic effect of silicon have been extensively studied before,and using the thermo-optic properties of two-dimensional materials to control silicon-based microring devices can exhibit superior performance.In this paper,by combining the excellent characteristics of platinum diselenide with micro-ring resonators,two siliconbased micro-ring thermo-optic modulators based on platinum diselenide are proposed and prepared.The main contents are as follows:(1)The basic principles and important parameters of the micro-ring resonator are analyzed.The research status of silicon-based optical modulators based on two-dimensional materials is reviewed.The optical and electrical properties of platinum diselenide are introduced.The manufacturing process and test methods of silicon waveguide devices are introduced.(2)A silicon-based micro-ring modulator based on light-to-heat conversion characteristics of platinum diselenide is proposed and implemented.The pump light directly illuminates the micro-ring covered by the platinum diselenide film,and the effective refractive index of the waveguide can be tuned by changing the temperature,so that the transmission spectrum of the device is shifted,and the photothermal modulation function is realized.The experimentally measured tuning efficiency of the device is 0.0040 nm m W-1,and the 10%~90% rise and fall times are 304 ?s and 284 ?s,respectively.(3)A silicon-based platinum diselenide electrothermal modulator is proposed and produced.The platinum diselenide is used as the micro-heater that can directly contact the surface of the waveguide,and the Joule heating effect of the material is used to realize the electrothermal modulation function.According to the resistance and spectrum test results of the device,combined with numerical simulation,the influence of material thickness,length and electrode design on the performance of the modulator is analyzed.