Photonic crystal triple wavelength division multiplexer based on application of FTTH

The invention relates to a photonic crystal triple wavelength division multiplexer based on the application of FTTH (fiber to the home). The division multiplexer adopts the two-dimensional photonic crystal with hexagonal lattice air holes on a high refractivity flat plate. The photonic crystal triple wavelength division multiplexer contains four photonic crystal line-defect waveguides and two photonic crystal point-defect micro-cavities, wherein the four photonic crystal line-defect waveguides are an input waveguide, a first channel, a second channel and a third channel respectively; the two defect micro-cavities are a downlink micro-cavity with the wavelength of 1490nm and a downlink micro-cavity with the wavelength of 1310nm; the two micro-cavities are placed on both sides of the input waveguide; and the second channel and the third channel are separately connected with the 1310nm of downlink micro-cavity and the 1490nm of downlink micro-cavity, and the tail end of the input waveguide is connected with the