Inverse Design And Implementation Of Silicon Photonic Power Divider With Arbitrary Power Ratios

Recent years,with the development of optical communication technology rapidly,it has a great influence on people's lives already.Because the pursuit of information is getting higher and higher,it is our duty to increase the transmission speed,reduce power consumption and improve the level of integration.After integrated optical circuit has been proposed in the 20 th century,it takes a great place in the communication industry.There are three system in photonic integrated system: PLC,In P and Si.The first two systems are both mature technology.But people no longer satisfied with the performance of these two systems with high cost,silicon system gradually enter the public's awareness.Nowadays,with the rapid development of silicon photonics,the research of silicon devices(active and passive devices)has become one of the directions,such as modulators,detectors,filters,couplers,attenuators and the like.This article is mainly use a universal structure to achieve an arbitrary ratio of output optical splitters.The main research include the following aspects:After a large amount of literature research and analysis of the development of optical power splitter and reverse design automatic optimization method,the multi-mode interference coupler is selected as the basic model of the design and the pixel-based automatic optimization method is used as the main optimization method.Our purpose is to achieve a multi-port power splitter with arbitrary splitting ratios.We have analyzed the working principle of multi-mode interferometer.Based on SOI with top layer silicon thickness of 220 nm,the research is based on the multi-mode interferometer as a start,using a self-designed nonlinear optimization method to do the constraint,the simulation is carried out by the finite difference time-domain method,and finally four power divider with super-compact size,different power splitting ratio and different output ports are obtained.Device performance is good,and available in a certain bandwidth.Also three-port device achieved arbitrary ratios which the traditional three-port power divider can't achieve.We have done the samples which prepared by the semiconductor preparation process according to the standards.Multiple samples were successfully prepared and each device in the sample was taken photos by scanning electron micrograph.After that,we set up test lighting path in 1550 nm.At last,the sample was scanned in different wavelength and the data were normalized by Origin and converted to the corresponding transmission efficiency,then calculate the power ratio of each device.The experimental values are close to the simulation results,and the fabrication of the device allows a certain process error,which proves the feasibility of this method to make automatically optimized device.We believe that by continue improving the method and preparation process,this method can be used in more silicon photonics devices,helping to significantly improve device integration and performance,as well as achieving some unattainable performance with conventional devices.