采用硅基二氧化硅阵列波导光栅设计并制作了宽带低串扰单纤三向器.为使三个波长间隔相差较大的输出谱获得相同的带宽，在输出波导与罗兰圆交界采用了不同结构的多模干涉器.二维有限差分束传播法的模拟结果表明，理论上1 310 nm、1 490 nm和1 550 nm波长的3 dB带宽分别达到23 nm、23.5 nm和25 nm，插入损耗均为4 dB，1 310 nm波长的串扰小于-40 dB，1 490 nm与1 550 nm波长间串扰小于-40 dB；采用宽带光源测试结果表明，1 550 nm波长的3 dB带宽为23 nm，采用三个独立窄带光源测试结果表明，三个波长的插入损耗均为7 dB，1 310 nm波长的串扰小于-40 dB，1 490 nm与1 550 nm波长间的串扰小于-39 dB，测试与模拟结果基本一致.

A wide bandwidth low crosstalk triplexer is designed and fabricated using silica arrayed waveguide gratings(AWGs).In order to obtain wide bandwidth for all three wavelengths whose wavelength differences are large，multimode interferences(MMIs)with different structures are used at the junction between output waveguides and Rowland circle.Using two-dimensional finite difference beam propagation method，the simulated results show that 3 dB bandwidth of the designed triplexer are up to 23 nm,23.5 nm and 25 nm for 1 310 nm,1 490 nm and 1 550 nm，respectively.The insertion losses all are 4 dB.The crosstalk is less than -40 dB for 1 310 nm，and are less than -40 dB for 1 490 nm and 1 550 nm.Using broadband light source，the measured results show that 3dB bandwidth for 1 550 nm is 23 nm.Using three independent narrowband light sources，the measured results show that the insertion losses of the three waves all are 7 dB.The crosstalk is less than -40 dB for 1 310 nm，and are less than -39 dB for 1490 nm and 1 550 nm.The measured and simulated results are basically consistent.