It is a technical difficulty of fabricating laser resonator gratings that the -1 and 0 order diffraction efficiencies of the gratings are equal to expectation values synchronously in controlling zero plane width of grating groove by ruling technology. Based on the electromagnetic theory of gratings

the triangle model and design method of laser resonator gratings with 0 order coupling-out and -1 order oscillation are proposed according to the characteristics of TM polarization in non-anomaly region. The characteristics are that the change gradient of diffraction efficiency of the TM polarized wave in the region close to λ/d≈1.414 is small

and the diffraction efficiency is increased with a blazed angle and decreased with an apex angle monotonically. This model can realize the random energy distributions of 0 and -1 order diffraction efficiencies and can avoid the uncertainty of technique coming from old methods and reduce the fabricating difficulty.The model is used to fabricate a grating with diffraction efficiency of 65% and its efficiency error is only 0.6% at 10.6 μm. Moreover

the method can also be applied to design a grating with -1 order oscillation and -1 order coupling-out

so that the design method and fabrication technology of two kinds of gratings are unified.