An improved Y defect-based photonic crystal optical splitter is proposed so as to improve the transmittance of its output ports.Lead-in defects are introduced into the complete 2-D photonic crystal to form a 1×4 Y-type photonic crystal splitter.Each of the output ports is enabled to have a higher transmittance by regulating the radiuses of the four dielectric cylinders in the first branch

while flexible adjustment of the high transmittance and output optical energy at the output ports can be achieved by changing the radius of one dielectric cylinder in the second branch.It is concluded that such a splitter can be extensively applied in the fields of optical circuit integration

integrated optics

low-light level information processing and optical communications in the future.