Study On Optical Filter And Its Array Based On Silicon

The development of the Internet and the popularity of intelligent devices have promoted the arrival of the big data era.Under the background of explosive growth of data flow and rapid development of artificial intelligence,the new requirements are brought to the information technology:one is to improve the transmission capacity of information,the other is to improve the computational performance of information processing.At present,the traditional information technology,as well as the information transmission,is based on electronic technology,which has encountered bottlenecks in bandwidth,loss,and the transmission capacity.The integrated electronic chip is used for information processing,and the photolithography accuracy of manufacturing process is gradually close to the theoretical limit,which slows down the development of the chip-computation performance.To solve these two problems mentioned above,silicon photonic technology is considered to be an effective solution.Silicon photonic technology takes photons as the transmission signals,which has the advantages in large bandwidth,long distance,large capacity,and low loss.It can solve the problem of mass data exchange in the data center.Moreover,the optical computing technology based on optical signals is nearly one thousand times faster than the electrical computing technology with the same power,which can greatly improve the information processing capacity of the chip and has received great attention all over the world.Silicon-based filter is an important research field of silicon photonic technology,which is the basic unit to realize complex signal processing in optical domain.The common optical structures of the optical filters include array waveguide gratings,Bragg gratings,Mach-Zehnder interferometers and microring resonators.Both Mach-Zehnder interferometer and microring resonator have the advantages in flexible structures and good tunability,which are also widely used in the design of neural networks and programmable logic arrays in optical computing.In this paper,a filter based on silicon with tunable bandwidth and central wavelength is designed by using the structure of microring–assisted Mach-Zehnder interferometer.The finite difference time domain method is used to simulate the performance of the proposed filter.The simulation results show that both the bandwidth and center wavelength of the filter can be tuned.The tuning range of the bandwidth is 1.4-10.6 nm,accounting for 11.5%-85%of the whole FSR.At the same time of tuning the bandwidth,the center wavelength can be moved continuously within the whole free spectrum range(12.5nm).During the adjustment of bandwidth and central wavelength,the passband loss is less than 1d B and the stopband extinction ratio is more than 20d B.The effective size of the device is about 40×60?m~2?In this paper,we also researched a typical array of MZI.Based on this array,a silicon-based optical wavelength division multiplexer is designed and simulated.The simulation results show that the wavelength division multiplexer can multiplex 8 wavelength channels in the range of 1.535-1.57?m.The effective size of the device is about 300×600?m~2,the passband loss is less than2d B,and the minimum stopband extinction ratio is 21d B.It can be applied to the silicon-based wavelength division multiplexing transceiver module of optical computing equipment and large-scale computer center.