S形弯曲波导是集成光器件中不可缺少的部分。对比分析了常见不同形状的S形光波导的传输损耗,找到了低损耗的余弦形状。在Marcuse弯曲波导研究的基础上,通过曲线拟合方法,得到了几种近似计算损耗的公式。用Matlab进行仿真,得到了损耗曲线。与传统低坡模型进行对比分析,以找到与实际值最接近的模型。结果表明,高斯曲线拟合方法可以更好地描述余弦形状波导的损耗。 S-bend waveguide is an indispensable part of the integrated optical device. The transmission loss of common S-shaped optical waveguides with different shapes is analyzed and compared, and the cosine shape with low loss is found. Based on the Marcuse flexural waveguide, several formulas for calculating the loss are obtained by the curve fitting method. Using Matlab simulation, the loss curve was obtained. Compared with the traditional low-slope model to find the closest model with the actual value. The results show that the Gaussian curve fitting method can better describe the cosine-shaped waveguide loss.