塑料矩形相位光栅波分复用器可有效利用塑料光纤的带宽资源,提高城域接入网的有效接入带宽。推导了在最佳入射角下,基于矢量衍射理论求解的矩形相位光栅-1级衍射效率公式,数值模拟了TE/TM偏振的有效模指数与光栅常数的关系。模拟结果表明,折射率为1.58、占空比为0.5的矩形相位光栅在入射波长为1.5μm的入射光波照射下,TE/TM偏振能够同时达到最高衍射效率所对应的最佳光栅常数为0.82μm,刻槽深度为1.8μm。实际测量了不同入射角下,塑料矩形相位光栅的归一化衍射光强与入射角的关系,研究结果表明,在最佳入射角条件下,塑料矩形相位光栅的偏振相关损耗可低于0.5dB。 Plastic rectangular phase grating wavelength division multiplexer can effectively utilize the bandwidth resources of plastic optical fiber and improve the effective access bandwidth of metro access network. The formula of -1st order diffraction efficiency of rectangular phase grating based on vector diffraction theory is deduced at the optimal incident angle, and the relationship between the effective mode index of TE / TM polarization and the grating constant is numerically simulated. The simulation results show that the optimal grating constant of TE / TM polarization can achieve the highest diffraction efficiency at the same time when the rectangular grating with a refractive index of 1.58 and a duty cycle of 0.5 is irradiated by the incident light with the incident wavelength of 1.5μm is 0.82μm , Notch depth of 1.8μm. The relationship between normalized diffraction intensity and angle of incidence of plastic rectangular phase grating was measured under different incident angles. The results show that the polarization dependent loss of plastic rectangular phase grating can be lower than 0.5dB under the optimal incident angle .