The Design And Optimization Of Two-dimension Photonic Crystal Waveguide Wavelength Division Multiplexing

Wavelength division multiplexing (WDM) is the one of the most useful technology of all-fiber network communication system. It is used in seismometers, aerospace, construction of bridges and other areas. The traditional WDM is all along blocked by large size, high losses and unstable transmission. Photonic crystal waveguides (PCW) have attracted lots of research interests in design of WDM, due to their many advantages, such as high transfer rates, low loss transmission and good stability. In addition, photonic crystals, which design flexibility, can be easily prepared many types of optical devices. Therefore, PCW-WDM with high integrates, simple design and high transmission rate become hot spots and trends.In this paper, firstly, two WDM are designed and optimized based on two parallel photonic crystal waveguide coupling and decoupling properties. Next, new type WDM are designed and optimized based on self imaging effect and coupling properties.1. Three-wavelength WDM based on single-mode photonic crystal waveguideA new type three-wavelength WDM based on two dimension photonic crystals waveguide is designed according to the theory of coupling and decoupling. It achieves to separate three communication wavelengths. FDTD method is used to simulate the efficiency of the device, and the simulated results show that higher transmittance is achieved by adjusting the size of a row of dielectric rods. The size of device is23μm×9μm. For the three wavelengths (1310nm,1490nm,1550nm), the transmission rate are86%、87%、85%. The multiplexer structure is simple, compact size, high reliability.2. Four-wavelength WDM based on single-mode photonic crystal waveguideA new type four-wavelength WDM based on two dimension photonic crystals waveguide is designed according to the theory of coupling and decoupling. It achieves to separate four wavelengths. The simulated results show that higher transmittance is achieved by adjusting the size of a row of dielectric rods and adding dielectric rods in the incident medium. Further research shows that adding directional coupler can effectively increase the isolation of the system. The size of device is44μm×18μm. For the four wavelengths (1310nm,1490nm,1550nm,1670nm), the transmission rate are95%,87%,82%and96%, and the isolation rates are19.7,15.4,13.1and19.8dB, respectively. Compared with the3-wavelength WDM, this device has better transmission and isolation.3. three-wavelength WDM based on multimode photonic crystal waveguideA new type three-wavelength WDM is designed according to self-imaging phenomena in multi-mode and two parallel coupled photonic crystal waveguides. The size of device is43μm×10μm. For the three wavelengths (1310nm,1490nm,1550nm), the transmission rate are92%、90%、84%. Compared with the first3-wavelength WDM, this device has better transmission.