入射光在光栅内传输时将激发产生离散模.本文采用模态法调节光栅内离散模的传输特性，使TE和TM偏振光所激发的0、1模为传输模，其余高阶模为消逝模.通过调控0模和1模间的累积相位差，对衍射光进行调控，实现了－1级近100%的高效衍射.采用模态法分三部设计了共振域的矩形全偏振闪耀光栅：1）根据光栅的共振条件给出光栅周期，光栅周期越大槽深越小；2）根据特征模方程计算出光栅占空比；3）根据耦合模条件计算机光栅槽深.实验结果表明，该光栅的TE和TM偏振光同时具备近100%的－1级衍射效率.给出了633 nm波长－1级矩形石英全偏振闪耀光栅的典型设计实例，计算结果表明：所设计的全偏振闪耀光栅对TE和TM偏振入射光的－1级衍射效率分别高达96.7%和98.1%，且具有较宽的入射角及入射波长的变化适应范围，较大的制作容差.

A plan wave incident upon the grating will excite discrete modes. The modes with n2eff>0 can propagate through the gratings, while those with n2eff<0 are evanescent modes. The basic idea behind the simplified modal investigation is the excitation and coupling of the propagating modes in gratings. If an odd number multiple phase difference is accumulated for the first two propagating modes, the incident light will be diffracted into the －1st order with nearly 100 % diffraction efficiency. A highly efficient full polarization blazed grating with rectangular groove was designed theoretically by modal method in the resonance domain. The design procedure of the full polarization rectangular blazed grating could be divided into three steps. Step 1: present the grating period in the resonance domain. Step 2: present fill factor by the eigenvalue functions of the grating. Step 3: present groove depth based on the phase difference of the propagating modes. As an example, the design of the fused silica full polarization rectangular blazed grating was demonstrated for the wavelength of 633 nm, which has about 96.7% and 98.1% negative first-order diffraction efficiency for TE and TM polarizations, respectively. The full polarization blazed grating with fused silica has a wide-band incident angles and incident wavelengths, which especially has high fabrication tolerances.