An ultracompact triplexer is designed based on silicon nanowire AWG for FTTH.The output optical fields simulated by 2D-FDTD are clear,which shows the demultiplexing function for download 1 490 nm and 1 550 nm and the multiplexing function for upload 1 310 nm.The further simulated output spectra show that the output power for 1 490 nm,1 550 nm and 1 310 nm are 0.49 mW,0.49 mW and 0.55 mW,respectively,when the input power for three wavelengths are all 1mW.So the corresponding insertion loss are 3.1 dB,3.1 dB ...