Design And Study Of The 90 Degree Bending Waveguides With High Transmission Performance Based On 2D Cube Lattice Photonic Crystal

In the year 1987, E.Yablonovitch and S.John had proposed the concept of photonic crystals(Ph Cs), which could be co nsidered as an artificial micro-structure composed with two or more dielectrics with different εs, and the dielectrics arrayed periodically. The Ph Cs can be used to construct lots of all-optical devices, such as Ph C waveguides(PCWs), Ph C logic gates, Ph C resonators, and Ph C light switches because it can provide some useful attributions such as optical bandgaps and light localization and has great application potential in all-optical integrating circuits. PCWs are the most fundamental component in all devices based on Ph Cs, and they are as important as wires in electronic integrated circuits. The study about 90-degree bent PCWs began in the year 1998, but none of the articles could provide a satisfying transmission performance. We propose a general method named “Multi-scatting Compensation Method” for eliminating the reflection of waves in photonic crystal waveguides by introducing extra scatters inside the PCWs, and we successfully designed a number of 90-degree bent PCWs with this method. The PCWs designed can work well with properties such as high return loss(RL), low insertion loss(IL), small size, low power consumption, highly integratable, and easy to be fabricated. Moreover, these PCWs can be adjusted to any requred operating wavelength to acquire well performance through changing their structures subtly.The study and work in this paper are listed as below:1. We proposed a general method, based on the theory “Multi-scatting Compensation Method”, for eliminating the reflection of waves in photonic crystal waveguides by introducing extra scatterers inside the PCWs, which can be used to design general waveguides.2. We designed a 90-degree bent PCW structure based on 2D cubic lattice Ph C composed with silicon background circular which can be described as “rods- in-airs(RIA)”, and placed two silicon circular rods as scatterers.3. We adjusted the scatterer ’s structure parameters through simulations, and finally got the best result for RL=43d B and IL=0.0022 d B.