Optimization and simulation are performed for a polymer four-port microring optical router with three channel wavelengths, which contains four-group basic routing elements with two different ring radii. In terms of microring resonance theory, coupled mode theory and transfer matrix method, expressions of output power of basic routing element and optical router are derived. In order to realize single-mode propagation, low optical transmission loss and phase match between microring waveguide and channel waveguide, the device parameters are optimized. With the selected three channel wavelengths of 1550 nm, 1552 nm and 1554 nm, characteristics are calculated and analyzed, including output spectrum, insertion loss and crosstalk. Simulation results indicate that the device has 12 possible I/O routing paths, the insertion losses of three channel wavelengths along their routing paths are within the range of 0.02-0.61 dB, the maximum crosstalk between the on-port along each routing path and other off-ports is less than-39 dB, and the device footprint size is ~0.13 mm2. Based on the proposed structure, through proper selection on ring radius, the routing structure can also be used for other channel wavelengths. Therefore, the designed structure shows wide applications in integrated optical networks-on-chip(NoC).
The analysis on the traditional asymmetric Mach-Zehnder interferometer (AMZI) optical filter based on two 3 dB directional couplers (DCs) shows that by adding an additional nonlinear phase generated by phase-generating coupler (PGC) to the original phase difference of the AMZI, its non-periodic frequency response can be modified, and a strictly periodic spectrum can be obtained. A novel structure of the AMZI filter using two PGCs before and after the AMZI region is proposed. With the needed free spectrum range (FSR) of 20 nm, the design and optimization of the device are performed using polymer SU-8 as the core and PMMA-GMA as the buffer. Though the insertion loss (IL) gets larger than that of the traditional AMZI filter, the FSR is nearly uniform as the expected period of 20 nm.
A novel 1×2 polymer electro-optic(EO)switch based on seven vertical-turning serial-coupled microrings is proposed for dropping crosstalk and obtaining flat boxlike spectrum.The device structure,theory and formulation are presented,and the microring resonance order and coupling gaps are optimized.The switching voltage of the device for obtaining crosstalk lower than 30 dB under through state is decided to be about 1.86 V.Under the operation voltages of 0 V(drop state)and 1.86 V(through state),the switching performance is characterized,and the output spectrum is analyzed.The calculation results show that the crosstalk at through state and that at drop state are 30.2 dB and 53.2 dB,respectively,while the insertion losses are 0.86 dB and 3.18 dB,respectively.Owning to the seven serial-coupled microrings resonance structure,the proposed switch reveals the favorable boxlike spectrum compared with the simple device with only one microring,and thus the crosstalk under drop state is improved from 26.8 dB to 53.2 dB.Due to the low crosstalk,this device can be used in optical networks-on-chip for signal switching and routing.
研制了一种新型全聚合物49信道绝热低偏振相关阵列波导光栅(AWG)芯片。利用直接紫外光写入技术,实现了波导芯片的设计与制备。利用Matlab软件对AWG的传输特性进行了优化模拟,通过对聚合物衬底的热膨胀系数和聚合物波导的热光系数进行调控,得到了器件良好的绝热低偏振相关特性。测得AWG的中心波长为1550.918 nm,波长间隔为0.8 nm,插入损耗的信道变化范围是5.51 d B^10.62 d B,串扰大于20 d B,偏振漂移和温度变化分别是0.08 nm和0.03 nm/K。这种新技术十分适用于高性能多功能集成光路中,具有广阔的应用前景。
