大截面单模脊波导器件的几何结构满足单模条件并不意味着波导工作在最佳状态。漏泄模的干扰往往不容忽视。标量有限差分波束传输法(FDBPM)被用来计算具有不同几何尺寸的单模脊波导漏泄模的衰减度。当漏泄模衰减最大时,脊波导的几何尺寸最优。经过优化之后的脊波导,仍然满足单模条件,但漏泄模的衰减很大,对主模不构成干扰。对于一个脊宽固定为2μm、脊高比率固定为0.45的典型单模波导,将脊波导总高作为可变参数,在总高为5.4~1.3μm的范围内,计算不同波导尺寸下的漏泄模衰减度,计算表明,总高度2.25μm是最佳波导尺寸。 The geometry of a large cross-section single-mode ridge waveguide device that satisfies single-mode conditions does not mean that the waveguide works optimally. Leakage of interference often can not be ignored. Scalar Finite Difference Beam Transmission (FDBPM) is used to calculate the attenuation of single mode ridge waveguide leakage modes with different geometries. When the leakage mode attenuation maximum, ridge waveguide geometry optimal. After optimization, the ridge waveguide still satisfies the single-mode condition, but the attenuation of the leakage mode is large and does not interfere with the main mode. For a typical single-mode waveguide with a ridge width of 2μm and a ridge-height ratio of 0.45, the total height of the ridge waveguide is used as a variable parameter, and the leakage modes at different waveguide sizes are calculated in a total height range of 5.4-1.3μm Attenuation, calculation shows that the total height of 2.25μm is the best waveguide size.