降低AWG插入损耗和串扰设计新方法

在AWG器件的设计中引入了抛物线型的楔形波导结构,根据过渡区理论优化了引入的抛物线型楔形结构的形状和尺寸.采用抛物线型楔形结构代替直线型楔形结构,AWG的插入损耗降低了2 dB左右.在优化参数时使输出/输入波导间距与阵列波导间距取不同的值,并使输出/输入波导间距适当增大,而阵列波导间距取较小值,这样使得串扰降至－30 dB以下且插入损耗保持在低水平.运用光束传播方法给出器件的输出光谱并证实了理论上预想的结果.

A New Design to Reduce Insertion Loss and Crosstalk of AWG

The parabolic taper structure was introduced which is smoother than the linear taper. The structure of the parabolic taper waveguides was optimized using the transition region theory. By introducing the parabolic taper, the insertion loss reduced more than 2 dB compared with using the linear one. Through evaluating the pitches of adjacent input/output waveguides ΔX and arraying waveguides d as different values, the value of ΔX was chosen about 2.5 times of d by enlarging the pitches of adjacent input/output waveguides, and a crosstalk under -30 dB was obtained. These proposed methods considerably reduced the insertion loss and the crosstalk of AWG without any more difficulties in fabricating the AWG device which can also be easily applied to AWG of various materials.